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1.  Trauma and psychotic experiences: transnational data from the World Mental Health Survey 
Traumatic events are associated with increased risk of psychotic experiences, but it is unclear whether this association is explained by mental disorders prior to psychotic experience onset.
To investigate the associations between traumatic events and subsequent psychotic experience onset after adjusting for post-traumatic stress disorder and other mental disorders.
We assessed 29 traumatic event types and psychotic experiences from the World Mental Health surveys and examined the associations of traumatic events with subsequent psychotic experience onset with and without adjustments for mental disorders.
Respondents with any traumatic events had three times the odds of other respondents of subsequently developing psychotic experiences (OR=3.1, 95% CI 2.7–3.7), with variability in strength of association across traumatic event types. These associations persisted after adjustment for mental disorders.
Exposure to traumatic events predicts subsequent onset of psychotic experiences even after adjusting for comorbid mental disorders.
PMCID: PMC5709675  PMID: 29097400
2.  Association between psychotic experiences and subsequent suicidal thoughts and behaviors: A cross-national analysis from the World Health Organization World Mental Health Surveys 
JAMA psychiatry  2017;74(11):1136-1144.
Community-based studies have linked psychotic experiences (PEs) with increased risks of suicidal thoughts and behaviors (STBs). However, it is not known if these associations vary across the life-course or if mental disorders (antecedent to the STBs) contribute to these associations.
To examine the temporal association between PEs and subsequent STBs across the life span as well as the influence of mental disorders (antecedent to the STBs) on these associations.
A total of 33,370 adult respondents across 19 countries from the WHO World Mental Health (WMH) Surveys were assessed for PEs, STBs (ideation, plans, and attempts), and 21 DSM-IV mental disorders. Discrete-time survival analysis was used to investigate the associations of PEs with subsequent onsets of STBs.
Prevalence and frequency of STBs with PEs, and odds ratios and 95%CIs.
Of 33 370 included participants, among those with PEs (n = 2488), the lifetime prevalence (SE) of suicidal ideation, plans, and attempts was 28.5%(1.3), 10.8%(0.7), and 10.2%(0.7), respectively. Respondents with 1 or more PEs had 2-fold increased odds of subsequent STBs after adjusting for antecedent or intervening mental disorders (suicidal ideation: odds ratio, 2.2; 95%CI, 1.8-2.6; suicide plans: odds ratio, 2.1; 95%CI, 1.7-2.6; and suicide attempts: odds ratio, 1.9; 95%CI, 1.5-2.5). There were significant dose-response relationships of number of PE types with subsequent STBs that persisted after adjustment for mental disorders. Although PEs were significant predictors of subsequent STB onset across all life stages, associations were strongest in individuals 12 years and younger. After adjustment for antecedent mental disorders, the overall population attributable risk proportions for lifetime suicidal ideation, plans, and attempts associated with temporally prior PEs were 5.3%, 5.7%, and 4.8%, respectively.
PEs are associated with elevated odds of subsequent STBs across the life-course that cannot be explained by antecedent mental disorders. These results highlight the importance of including information about PEs in screening instruments designed to predict STBs.
PMCID: PMC5710219  PMID: 28854302
3.  Cross-national Epidemiology of Panic Disorder and Panic Attacks in the World Mental Health Surveys 
Depression and anxiety  2016;33(12):1155-1177.
The scarcity of cross-national reports and the changes in DSM-5 regarding panic disorder (PD) and panic attacks (PAs) call for new epidemiological data on PD and PAs and its subtypes in the general population.
To present representative data about the cross-national epidemiology of PD and PAs in accordance with DSM-5 definitions.
Design and Setting
Nationally representative cross-sectional surveys using the World Health Organization Composite International Diagnostic Interview version 3.0.
Respondents (n=142,949) from 25 high, middle and lower-middle income countries across the world aged 18 years or older.
Main Outcome Measures
PD and presence of single and recurrent PAs.
Lifetime prevalence of PAs was 13.2% (s.e. 0.1%). Among persons that ever had a PA, the majority had recurrent PAs (66.5%; s.e. 0.5%), while only 12.8% fulfilled DSM-5 criteria for PD. Recurrent PAs were associated with a subsequent onset of a variety of mental disorders (OR 2.0; 95% CI 1.8–2.2) and their course (OR 1.3; 95% CI 1.2–2.4) whereas single PAs were not (OR 1.1; 95% CI 0.9–1.3 and OR 0.7; 95% CI 0.6–0.8). Cross-national lifetime prevalence estimates were 1.7% (s.e. 0.0%) for PD with a median age of onset of 32 (IQR 20–47). Some 80.4% of persons with lifetime PD had a lifetime comorbid mental disorder.
We extended previous epidemiological data to a cross-national context. The presence of recurrent PAs in particular is associated with subsequent onset and course of mental disorders beyond agoraphobia and PD, and might serve as a generic risk marker for psychopathology.
PMCID: PMC5143159  PMID: 27775828
4.  Childhood adversities and post-traumatic stress disorder: evidence for stress sensitisation in the World Mental Health Surveys* 
Although childhood adversities are known to predict increased risk of post-traumatic stress disorder (PTSD) after traumatic experiences, it is unclear whether this association varies by childhood adversity or traumatic experience types or by age.
To examine variation in associations of childhood adversities with PTSD according to childhood adversity types, traumatic experience types and life-course stage.
Epidemiological data were analysed from the World Mental Health Surveys (n = 27 017).
Four childhood adversities (physical and sexual abuse, neglect, parent psychopathology) were associated with similarly increased odds of PTSD following traumatic experiences (odds ratio (OR) = 1.8), whereas the other eight childhood adversities assessed did not predict PTSD. Childhood adversity-PTSD associations did not vary across traumatic experience types, but were stronger in childhood-adolescence and early-middle adulthood than later adulthood.
Childhood adversities are differentially associated with PTSD, with the strongest associations in childhood–adolescence and early-middle adulthood. Consistency of associations across traumatic experience types suggests that childhood adversities are associated with generalised vulnerability to PTSD following traumatic experiences.
PMCID: PMC5663970  PMID: 28935660
5.  The cross-national epidemiology of specific phobia in the World Mental Health Surveys 
Psychological medicine  2017;47(10):1744-1760.
Although specific phobia is highly prevalent, associated with impairment, and an important risk factor for the development of other mental disorders, cross-national epidemiological data are scarce, especially from low and middle-income countries. This paper presents epidemiological data from 22 low, lower-middle, upper-middle and high-income countries.
Data came from 25 representative population-based surveys conducted in 22 countries (2001–2011) as part of the World Health Organization World Mental Health Surveys initiative (N=124,902). The presence of specific phobia as defined by the Diagnostic and Statistical Manual of Mental Disorders, fourth edition was evaluated using the World Health Organization Composite International Diagnostic Interview.
The cross-national lifetime and 12-month prevalence rates of specific phobia were, respectively, 7.4% and 5.5%, being higher in females (9.8% and 7.7%) than in males (4.9% and 3.3%) and higher in high and higher-middle income countries than in low/lower-middle income countries. The median age of onset was young (8 years). Of the 12-month patients, 18.7% reported severe role impairment (13.3%–21.9% across income groups) and 23.1% reported any treatment (9.6%–30.1% across income groups). Lifetime comorbidity was observed in 60.2% of those with lifetime specific phobia, with the onset of specific phobia preceding the other disorder in most cases (72.6%). Interestingly, rates of impairment, treatment-use and comorbidity increased with the number of fear subtypes.
Specific phobia is common and associated with impairment in a considerable percentage of cases. Importantly, specific phobia often precedes the onset of other mental disorders, making it a possible early-life indicator of psychopathology vulnerability.
PMCID: PMC5674525  PMID: 28222820
specific phobia; epidemiology; comorbidity; cross-national; impairment; treatment
6.  Cross-sectional Comparison of the Epidemiology of DSM-5 Generalized Anxiety Disorder Across the Globe 
JAMA psychiatry  2017;74(5):465-475.
Generalized anxiety disorder (GAD) is poorly understood compared with other anxiety disorders, and debates persist about the seriousness of this disorder. Few data exist on GAD outside a small number of affluent, industrialized nations. No population-based data exist on GAD as it is currently defined in DSM-5.
To provide the first epidemiologic data on DSM-5 GAD and explore cross-national differences in its prevalence, course, correlates, and impact.
Data come from the World Health Organization World Mental Health Survey Initiative. Cross-sectional general population surveys were carried out in 26 countries using a consistent research protocol and assessment instrument. A total of 147 261 adults from representative household samples were interviewed face-to-face in the community. The surveys were conducted between 2001 and 2012. Data analysis was performed from July 22, 2015, to December 12, 2016.
The Composite International Diagnostic Interview was used to assess GAD along with comorbid disorders, role impairment, and help seeking.
Respondents were 147 261 adults aged 18 to 99 years. The surveys had a weighted mean response rate of 69.5%. Across surveys, DSM-5 GAD had a combined lifetime prevalence (SE) of 3.7%(0.1%), 12-month prevalence of 1.8%(0.1%), and 30-day prevalence of 0.8%(0). Prevalence estimates varied widely across countries, with lifetime prevalence highest in high-income countries (5.0% [0.1%]), lower in middle-income countries (2.8% [0.1%]), and lowest in low-income countries (1.6% [0.1%]). Generalized anxiety disorder typically begins in adulthood and persists over time, although onset is later and clinical course is more persistent in lower-income countries. Lifetime comorbidity is high (81.9% [0.7%]), particularly with mood (63.0% [0.9%]) and other anxiety (51.7% [0.9%]) disorders. Severe role impairment is common across life domains (50.6% [1.2%]), particularly in high-income countries. Treatment is sought by approximately half of affected individuals (49.2% [1.2%]), especially those with severe role impairment (59.4% [1.8%]) or comorbid disorders (55.8% [1.4%]) and those living in high-income countries (59.0% [1.3%]).
The findings of this study show that DSM-5 GAD is more prevalent than DSM-IV GAD and is associated with substantial role impairment. The disorder is especially common and impairing in high-income countries despite a negative association between GAD and socioeconomic status within countries. These results underscore the public health significance of GAD across the globe while uncovering cross-national differences in prevalence, course, and impairment that require further investigation.
PMCID: PMC5594751  PMID: 28297020
7.  The association between psychotic experiences and disability: results from the WHO World Mental Health Surveys 
Acta psychiatrica Scandinavica  2017;136(1):74-84.
While psychotic experiences (PEs) are known to be associated with a range of mental and general medical disorders, little is known about the association between PEs and measures of disability. We aimed to investigate this question using the World Mental Health surveys.
Lifetime occurrences of 6 types of PEs were assessed along with 21 mental disorders and 14 general medical conditions. Disability was assessed with a modified version of the WHO Disability Assessment Schedule. Descriptive statistics and logistic regression models were used to investigate the association between PEs and high disability scores (top quartile) with various adjustments.
Respondents with PEs were more likely to have top quartile scores on global disability than respondents without PEs (19.1% vs. 7.5%; χ2 = 190.1, p<.001) as well as greater likelihood of cognitive, social, and role impairment. Relationships persisted in each adjusted model. A significant dose-response relationship was also found for the PE type measures with most of these outcomes.
Psychotic experiences are associated with disability measures with a dose response relationship. These results are consistent with the view that PEs are associated with disability regardless of the presence of comorbid mental or general medical disorders.
PMCID: PMC5664954  PMID: 28542726
Psychotic experiences; disability; World Mental Health Survey; WHODAS
8.  Posttraumatic stress disorder associated with unexpected death of a loved one: Cross-national findings from the World Mental Health Surveys 
Depression and anxiety  2016;34(4):315-326.
Unexpected death of a loved one (UD) is the most commonly reported traumatic experience in cross-national surveys. However, much remains to be learned about PTSD after this experience. The WHO World Mental Health (WMH) Survey Initiative provides a unique opportunity to address these issues.
Data from 19 WMH surveys (n=78,023; 70.1% weighted response rate) were collated. Potential predictors of PTSD (respondent socio-demographics, characteristics of the death, history of prior trauma exposure, history of prior mental disorders) after a representative sample of UDs were examined using logistic regression. Simulation was used to estimate overall model strength in targeting individuals at highest PTSD risk.
PTSD prevalence after UD averaged 5.2% across surveys and did not differ significantly between high and low-middle income countries. Significant multivariate predictors included: the deceased being a spouse or child; the respondent being female and believing they could have done something to prevent the death; prior trauma exposure; and history of prior mental disorders. The final model was strongly predictive of PTSD, with the 5% of respondents having highest estimated risk including 30.6% of all cases of PTSD. Positive predictive value (i.e., the proportion of high-risk individuals who actually developed PTSD) among the 5% of respondents with highest predicted risk was 25.3%.
The high prevalence and meaningful risk of PTSD make UD a major public health issue. This study provides novel insights into predictors of PTSD after this experience and suggests that screening assessments might be useful in identifying high-risk individuals for preventive interventions.
PMCID: PMC5661943  PMID: 27921352
PTSD/Posttraumatic Stress Disorder; epidemiology; life events/stress; trauma; crossnational; international
9.  Trauma and PTSD in the WHO World Mental Health Surveys 
Background: Although post-traumatic stress disorder (PTSD) onset-persistence is thought to vary significantly by trauma type, most epidemiological surveys are incapable of assessing this because they evaluate lifetime PTSD only for traumas nominated by respondents as their ‘worst.’
Objective: To review research on associations of trauma type with PTSD in the WHO World Mental Health (WMH) surveys, a series of epidemiological surveys that obtained representative data on trauma-specific PTSD.
Method: WMH Surveys in 24 countries (n = 68,894) assessed 29 lifetime traumas and evaluated PTSD twice for each respondent: once for the ‘worst’ lifetime trauma and separately for a randomly-selected trauma with weighting to adjust for individual differences in trauma exposures. PTSD onset-persistence was evaluated with the WHO Composite International Diagnostic Interview.
Results: In total, 70.4% of respondents experienced lifetime traumas, with exposure averaging 3.2 traumas per capita. Substantial between-trauma differences were found in PTSD onset but less in persistence. Traumas involving interpersonal violence had highest risk. Burden of PTSD, determined by multiplying trauma prevalence by trauma-specific PTSD risk and persistence, was 77.7 person-years/100 respondents. The trauma types with highest proportions of this burden were rape (13.1%), other sexual assault (15.1%), being stalked (9.8%), and unexpected death of a loved one (11.6%). The first three of these four represent relatively uncommon traumas with high PTSD risk and the last a very common trauma with low PTSD risk. The broad category of intimate partner sexual violence accounted for nearly 42.7% of all person-years with PTSD. Prior trauma history predicted both future trauma exposure and future PTSD risk.
Conclusions: Trauma exposure is common throughout the world, unequally distributed, and differential across trauma types with respect to PTSD risk. Although a substantial minority of PTSD cases remits within months after onset, mean symptom duration is considerably longer than previously recognized.
PMCID: PMC5632781
Burden of illness; disorder prevalence and persistence; epidemiology; post-traumatic stress disorder (PTSD); trauma exposure
10.  Protocol for a cohort study of adolescent mental health service users with a nested cluster randomised controlled trial to assess the clinical and cost-effectiveness of managed transition in improving transitions from child to adult mental health services (the MILESTONE study) 
BMJ Open  2017;7(10):e016055.
Disruption of care during transition from child and adolescent mental health services (CAMHS) to adult mental health services may adversely affect the health and well-being of service users. The MILESTONE (Managing the Link and Strengthening Transition from Child to Adult Mental Healthcare) study evaluates the longitudinal course and outcomes of adolescents approaching the transition boundary (TB) of their CAMHS and determines the effectiveness of the model of managed transition in improving outcomes, compared with usual care.
Methods and analysis
This is a cohort study with a nested cluster randomised controlled trial. Recruited CAMHS have been randomised to provide either (1) managed transition using the Transition Readiness and Appropriateness Measure score summary as a decision aid, or (2) usual care for young people reaching the TB. Participants are young people within 1 year of reaching the TB of their CAMHS in eight European countries; one parent/carer and a CAMHS clinician for each recruited young person; and adult mental health clinician or other community-based care provider, if young person transitions. The primary outcome is Health of the Nation Outcome Scale for Children and Adolescents (HoNOSCA) measuring health and social functioning at 15 months postintervention. The secondary outcomes include mental health, quality of life, transition experience and healthcare usage assessed at 9, 15 and 24 months postintervention. With a mean cluster size of 21, a total of 840 participants randomised in a 1:2 intervention to control are required, providing 89% power to detect a difference in HoNOSCA score of 0.30 SD. The addition of 210 recruits for the cohort study ensures sufficient power for studying predictors, resulting in 1050 participants and an approximate 1:3 randomisation.
Ethics and dissemination
The study protocol was approved by the UK National Research Ethics Service (15/WM/0052) and equivalent ethics boards in participating countries. Results will be reported at conferences, in peer-reviewed publications and to all relevant stakeholder groups.
Trial registration number
ISRCTN83240263; NCT03013595 (pre-results).
PMCID: PMC5652531  PMID: 29042376
mental health; child and adolescent mental health services; transition; health services research; cluster randomised controlled trial; longitudinal cohort study; youth mental health; Europe
11.  Meta-analysis of the Interval between the Onset and Management of Bipolar Disorder 
To evaluate the length of the interval between the onset and the initial management of bipolar disorder (BD).
We conducted a meta-analysis using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Systematic searches located studies reporting estimates of the age of onset (AOO) and indicators of the age at initial management of BD. We calculated a pooled estimate of the interval between AOO and age at management. Factors influencing between-study heterogeneity were investigated using sensitivity analyses, meta-regression, and multiple meta-regression.
Twenty-seven studies, reporting 51 samples and a total of 9415 patients, met the inclusion criteria. The pooled estimate for the interval between the onset of BD and its management was 5.8 years (standardized difference, .53; 95% confidence interval, .45 to .62). There was very high between-sample heterogeneity (I 2 = 92.6; Q = 672). A longer interval was found in studies that defined the onset according to the first episode (compared to onset of symptoms or illness) and defined management as age at diagnosis (rather than first treatment or first hospitalization). A longer interval was reported among more recently published studies, among studies that used a systematic method to establish the chronology of illness, among studies with a smaller proportion of bipolar I patients, and among studies with an earlier mean AOO.
There is currently little consistency in the way researchers report the AOO and initial management of BD. However, the large interval between onset and management of BD presents an opportunity for earlier intervention.
PMCID: PMC5407546  PMID: 27462036
meta-analysis; bipolar disorders; age of onset; clinical management; duration of untreated bipolar disorder
12.  Association of DSM-IV Posttraumatic Stress Disorder With Traumatic Experience Type and History in the World Health Organization World Mental Health Surveys 
JAMA psychiatry  2017;74(3):270-281.
Previous research has documented significant variation in the prevalence of posttraumatic stress disorder (PTSD) depending on the type of traumatic experience (TE) and history of TE exposure, but the relatively small sample sizes in these studies resulted in a number of unresolved basic questions.
To examine disaggregated associations of type of TE history with PTSD in a large cross-national community epidemiologic data set.
The World Health Organization World Mental Health surveys assessed 29 TE types (lifetime exposure, age at first exposure) with DSM-IV PTSD that was associated with 1 randomly selected TE exposure (the random TE) for each respondent. Surveys were administered in 20 countries (n = 34 676 respondents) from 2001 to 2012. Data were analyzed from October 1, 2015, to September 1, 2016.
Prevalence of PTSD assessed with the Composite International Diagnostic Interview.
Among the 34 676 respondents (55.4% [SE, 0.6%] men and 44.6% [SE, 0.6%] women; mean [SE] age, 43.7 [0.2] years), lifetime TE exposure was reported by a weighted 70.3% of respondents (mean [SE] number of exposures, 4.5 [0.04] among respondents with any TE). Weighted (by TE frequency) prevalence of PTSD associated with random TEs was 4.0%. Odds ratios (ORs) of PTSD were elevated for TEs involving sexual violence (2.7; 95% CI, 2.0–3.8) and witnessing atrocities (4.2; 95% CI, 1.0–17.8). Prior exposure to some, but not all, same-type TEs was associated with increased vulnerability (eg, physical assault; OR, 3.2; 95% CI, 1.3–7.9) or resilience (eg, participation in sectarian violence; OR, 0.3; 95% CI, 0.1–0.9) to PTSD after the random TE. The finding of earlier studies that more general history of TE exposure was associated with increased vulnerability to PTSD across the full range of random TE types was replicated, but this generalized vulnerability was limited to prior TEs involving violence, including participation in organized violence (OR, 1.3; 95% CI, 1.0–1.6), experience of physical violence (OR, 1.4; 95% CI, 1.2–1.7), rape (OR, 2.5; 95% CI, 1.7–3.8), and other sexual assault (OR, 1.6; 95% CI, 1.1–2.3).
The World Mental Health survey findings advance understanding of the extent to which PTSD risk varies with the type of TE and history of TE exposure. Previous findings about the elevated PTSD risk associated with TEs involving assaultive violence was refined by showing agreement only for repeated occurrences. Some types of prior TE exposures are associated with increased resilience rather than increased vulnerability, connecting the literature on TE history with the literature on resilience after adversity. These results are valuable in providing an empirical rationale for more focused investigations of these specifications in future studies.
PMCID: PMC5441566  PMID: 28055082
13.  The cross-national epidemiology of social anxiety disorder: Data from the World Mental Health Survey Initiative 
BMC Medicine  2017;15:143.
There is evidence that social anxiety disorder (SAD) is a prevalent and disabling disorder. However, most of the available data on the epidemiology of this condition originate from high income countries in the West. The World Mental Health (WMH) Survey Initiative provides an opportunity to investigate the prevalence, course, impairment, socio-demographic correlates, comorbidity, and treatment of this condition across a range of high, middle, and low income countries in different geographic regions of the world, and to address the question of whether differences in SAD merely reflect differences in threshold for diagnosis.
Data from 28 community surveys in the WMH Survey Initiative, with 142,405 respondents, were analyzed. We assessed the 30-day, 12-month, and lifetime prevalence of SAD, age of onset, and severity of role impairment associated with SAD, across countries. In addition, we investigated socio-demographic correlates of SAD, comorbidity of SAD with other mental disorders, and treatment of SAD in the combined sample. Cross-tabulations were used to calculate prevalence, impairment, comorbidity, and treatment. Survival analysis was used to estimate age of onset, and logistic regression and survival analyses were used to examine socio-demographic correlates.
SAD 30-day, 12-month, and lifetime prevalence estimates are 1.3, 2.4, and 4.0% across all countries. SAD prevalence rates are lowest in low/lower-middle income countries and in the African and Eastern Mediterranean regions, and highest in high income countries and in the Americas and the Western Pacific regions. Age of onset is early across the globe, and persistence is highest in upper-middle income countries, Africa, and the Eastern Mediterranean. There are some differences in domains of severe role impairment by country income level and geographic region, but there are no significant differences across different income level and geographic region in the proportion of respondents with any severe role impairment. Also, across countries SAD is associated with specific socio-demographic features (younger age, female gender, unmarried status, lower education, and lower income) and with similar patterns of comorbidity. Treatment rates for those with any impairment are lowest in low/lower-middle income countries and highest in high income countries.
While differences in SAD prevalence across countries are apparent, we found a number of consistent patterns across the globe, including early age of onset, persistence, impairment in multiple domains, as well as characteristic socio-demographic correlates and associated psychiatric comorbidities. In addition, while there are some differences in the patterns of impairment associated with SAD across the globe, key similarities suggest that the threshold for diagnosis is similar regardless of country income levels or geographic location. Taken together, these cross-national data emphasize the international clinical and public health significance of SAD.
PMCID: PMC5535284  PMID: 28756776
Social anxiety disorder; Social phobia; Cross-national epidemiology; World Mental Health Survey Initiative
14.  Age of Onset and Lifetime Projected Risk of Psychotic Experiences: Cross-National Data From the World Mental Health Survey 
Schizophrenia Bulletin  2016;42(4):933-941.
Given the early age of onset (AOO) of psychotic disorders, it has been assumed that psychotic experiences (PEs) would have a similar early AOO. The aims of this study were to describe (a) the AOO distribution of PEs, (b) the projected lifetime risk of PEs, and (c) the associations of PE AOO with selected PE features.
Data came from the WHO World Mental Health (WMH) surveys. A total of 31 261 adult respondents across 18 countries were assessed for lifetime prevalence of PE. Projected lifetime risk (at age 75 years) was estimated using a 2-part actuarial method. AOO distributions were described for the observed and projected estimates. We examined associations of AOO with PE type metric and annualized PE frequency.
Projected lifetime risk for PEs was 7.8% (SE = 0.3), slightly higher than lifetime prevalence (5.8%, SE = 0.2). The median (interquartile range; IQR) AOO based on projected lifetime estimates was 26 (17–41) years, indicating that PEs commence across a wide age range. The AOO distributions for PEs did not differ by sex. Early AOO was positively associated with number of PE types (F = 14.1, P < .001) but negatively associated with annualized PE frequency rates (F = 8.0, P < .001).
While most people with lifetime PEs have first onsets in adolescence or young adulthood, projected estimates indicate that nearly a quarter of first onsets occur after age 40 years. The extent to which late onset PEs are associated with (a) late onset mental disorders or (b) declining cognitive and/or sensory function need further research.
PMCID: PMC4903064  PMID: 27038468
epidemiology; psychotic experiences; age of onset; lifetime prevalence; World Mental Health Survey
15.  Mental disorders among college students in the WHO World Mental Health Surveys 
Psychological medicine  2016;46(14):2955-2970.
Although mental disorders are significant predictors of educational attainment throughout the entire educational career, most research on mental disorders among students has focused on the primary and secondary school years.
The World Health Organization World Mental Health Surveys were used to examine the associations of mental disorders with college entry and attrition by comparing college students (n = 1,572) and nonstudents in the same age range (18–22; n = 4,178), including nonstudents who recently left college without graduating (n = 702) based on surveys in 21 countries (4 low/lower-middle income, 5 upper middle-income, 1 lower-middle or upper-middle at the times of two different surveys, and 11 high income). Lifetime and 12-month prevalence and age-of-onset of DSM-IV anxiety, mood, behavioural and substance disorders were assessed with the Composite International Diagnostic Interview.
One-fifth (20.3%) of college students had 12-month DSM-IV/CIDI disorders. 83.1% of these cases had pre-matriculation onsets. Disorders with pre-matriculation onsets were more important than those with post-matriculation onsets in predicting subsequent college attrition, with substance disorders and, among women, major depression the most important such disorders. Only 16.4% of students with 12-month disorders received any 12-month healthcare treatment for their mental disorders.
Mental disorders are common among college students, have onsets that mostly occur prior to college entry, in the case of pre-matriculation disorders are associated with college attrition, and are typically untreated. Detection and effective treatment of these disorders early in the college career might reduce attrition and improve educational and psychosocial functioning.
PMCID: PMC5129654  PMID: 27484622
Mental Illness; College; Education; College Dropout; College attrition; Epidemiology
16.  Association of Mental Disorders With Subsequent Chronic Physical Conditions 
JAMA psychiatry  2016;73(2):150-158.
It is clear that mental disorders in treatment settings are associated with a higher incidence of chronic physical conditions, but whether this is true of mental disorders in the community, and how generalized (across a range of physical health outcomes) these associations are, is less clear. This information has important implications for mental health care and the primary prevention of chronic physical disease.
To investigate associations of 16 temporally prior DSM-IV mental disorders with the subsequent onset or diagnosis of 10 chronic physical conditions.
Eighteen face-to-face, cross-sectional household surveys of community-dwelling adults were conducted in 17 countries (47 609 individuals; 2 032 942 person-years) from January 1, 2001, to December 31, 2011. The Composite International Diagnostic Interview was used to retrospectively assess the lifetime prevalence and age at onset of DSM-IV–identified mental disorders. Data analysis was performed from January 3, 2012, to September 30, 2015.
Lifetime history of physical conditions was ascertained via self-report of physician’s diagnosis and year of onset or diagnosis. Survival analyses estimated the associations of temporally prior first onset of mental disorders with subsequent onset or diagnosis of physical conditions.
Most associations between 16 mental disorders and subsequent onset or diagnosis of 10 physical conditions were statistically significant, with odds ratios (ORs) (95% CIs) ranging from 1.2 (1.0–1.5) to 3.6 (2.0–6.6). The associations were attenuated after adjustment for mental disorder comorbidity, but mood, anxiety, substance use, and impulse control disorders remained significantly associated with onset of between 7 and all 10 of the physical conditions (ORs [95% CIs] from 1.2 [1.1–1.3] to 2.0 [1.4–2.8]). An increasing number of mental disorders experienced over the life course was significantly associated with increasing odds of onset or diagnosis of all 10 types of physical conditions, with ORs (95% CIs) for 1 mental disorder ranging from 1.3 (1.1–1.6) to 1.8 (1.4–2.2) and ORs (95% CIs) for 5 or more mental disorders ranging from 1.9 (1.4–2.7) to 4.0 (2.5–6.5). In population-attributable risk estimates, specific mental disorders were associated with 1.5% to 13.3% of physical condition onsets.
These findings suggest that mental disorders of all kinds are associated with an increased risk of onset of a wide range of chronic physical conditions. Current efforts to improve the physical health of individuals with mental disorders may be too narrowly focused on the small group with the most severe mental disorders. Interventions aimed at the primary prevention of chronic physical diseases should optimally be integrated into treatment of all mental disorders in primary and secondary care from early in the disorder course.
PMCID: PMC5333921  PMID: 26719969
17.  Associations between DSM-IV mental disorders and subsequent onset of arthritis 
We investigated the associations between DSM-IV mental disorders and subsequent arthritis onset, with and without mental disorder comorbidity adjustment. We aimed to determine whether specific types of mental disorders and increasing numbers of mental disorders were associated with the onset of arthritis later in life.
Data were collected using face-to-face household surveys, conducted in 19 countries from different regions of the world (n = 52,095). Lifetime prevalence and age at onset of 16 DSM-IV mental disorders were assessed retrospectively with the World Health Organization (WHO) Composite International Diagnostic Interview (WHO-CIDI). Arthritis was assessed by self-report of lifetime history of arthritis and age at onset. Survival analyses estimated the association of initial onset of mental disorders with subsequent onset of arthritis.
After adjusting for comorbidity, the number of mood, anxiety, impulse-control, and substance disorders remained significantly associated with arthritis onset showing odds ratios (ORs) ranging from 1.2 to 1.4. Additionally, the risk of developing arthritis increased as the number of mental disorders increased from one to five or more disorders.
This study suggests links between mental disorders and subsequent arthritis onset using a large, multi-country dataset. These associations lend support to the idea that it may be possible to reduce the severity of mental disorder-arthritis comorbidity through early identification and effective treatment of mental disorders.
PMCID: PMC4884652  PMID: 26944393
arthritis; comorbidity; mental disorders; substance abuse
18.  The bi-directional associations between psychotic experiences and DSM-IV mental disorders 
The American journal of psychiatry  2016;173(10):997-1006.
While it is now recognized that psychotic experiences (PEs) are associated with an increased risk of later mental disorders, we lack a detailed understanding of the reciprocal time-lagged relationships between first onsets of PEs and mental disorders.
The WHO World Mental Health (WMH) surveys assessed lifetime prevalence and age-of-onset of PEs and 21 common DSM-IV mental disorders among 31,261 adult respondents from 18 countries.
Temporally primary PEs were significantly associated with subsequent first onset of 8 of the 21 mental disorders (major depressive disorder, bipolar disorder, generalized anxiety disorder, social phobia, post-traumatic stress disorder, adult separation anxiety disorder, bulimia nervosa, alcohol abuse), with ORs (95%CI) ranging from 1.3 (1.2–1.5; major depressive disorder) to 2.0 (1.5–2.6; bipolar disorder). In contrast, 18 of 21 primary mental disorders were significantly associated with subsequent first onset of PEs, with ORs (95% CI) ranging from 1.5 (1.0–2.1; childhood separation anxiety disorder) to 2.8 (1.0–7.8; anorexia nervosa).
While temporally primary PEs are associated with an elevated risk of several subsequent mental disorders, we found that most mental disorder are associated with an elevated risk of subsequent PEs. Further investigation of the underlying factors accounting for these time-order relationships might shed light on the etiology of PEs.
PMCID: PMC5175400  PMID: 26988628
19.  Associations between DSM-IV mental disorders and subsequent self-reported diagnosis of cancer 
Journal of psychosomatic research  2014;76(3):207-212.
The associations between mental disorders and cancer remain unclear. It is also unknown whether any associations vary according to life stage or gender. This paper examines these research questions using data from the World Mental Health Survey Initiative.
The World Health Organization Composite International Diagnostic Interview retrospectively assessed the lifetime prevalence of 16 DSM-IV mental disorders in face-to-face household population surveys in nineteen countries (n = 52,095). Cancer was indicated by self-report of diagnosis. Smoking was assessed in questions about current and past tobacco use. Survival analyses estimated associations between first onset of mental disorders and subsequently reported cancer.
After adjustment for comorbidity, panic disorder, specific phobia and alcohol abuse were associated with a subsequently self-reported diagnosis of cancer. There was an association between number of mental disorders and the likelihood of reporting a cancer diagnosis following the onset of the mental disorder. This suggests that the associations between mental disorders and cancer risk may be generalised, rather than specific to a particular disorder. Depression is more strongly associated with self-reported cancers diagnosed early in life and in women. PTSD is also associated with cancers diagnosed early in life.
This study reports the magnitude of the associations between mental disorders and a self-reported diagnosis of cancer and provides information about the relevance of comorbidity, gender and the impact at different stages of life. The findings point to a link between the two conditions and lend support to arguments for early identification and treatment of mental disorders.
PMCID: PMC5129659  PMID: 24529039
Cancer; Psychiatry; Mental disorder; Epidemiology
20.  Association between mental disorders and subsequent adult onset asthma 
Background and objectives
Associations between asthma and anxiety and mood disorders are well established, but little is known about their temporal sequence. We examined associations between a wide range of DSM-IV mental disorders with adult onset of asthma and whether observed associations remain after mental comorbidity adjustments.
During face-to-face household surveys in community-dwelling adults (n = 52,095) of 19 countries, the WHO Composite International Diagnostic Interview retrospectively assessed lifetime prevalence and age at onset of 16 DSM-IV mental disorders. Asthma was assessed by self-report of physician’s diagnosis together with age of onset. Survival analyses estimated associations between first onset of mental disorders and subsequent adult onset asthma, without and with comorbidity adjustment.
1,860 adult onset (21 years+) asthma cases were identified, representing a total of 2,096,486 person-years of follow up. After adjustment for comorbid mental disorders several mental disorders were associated with subsequent adult asthma onset: bipolar (OR=1.8; 95%CI 1.3–2.4), panic (OR=1.4; 95%CI 1.0–2.0), generalized anxiety (OR=1.3; 95%CI 1.1–1.7), specific phobia (OR=1.4; 95%CI 1.2–1.6); post-traumatic stress (OR=1.5; 95%CI 1.1–2.0); binge eating (OR=1.9; 95%CI 1.2–2.9) and alcohol abuse (OR=1.5; 95%CI 1.2–2.0). Mental comorbidity linearly increased the association with adult asthma. The association with subsequent asthma was stronger for mental disorders with an early onset (before age 21).
A wide range of temporally prior mental disorders are significantly associated with subsequent onset of asthma in adulthood. The extent to which asthma can be avoided or improved among those with early mental disorders deserves study.
PMCID: PMC5120389  PMID: 25263276
Asthma; Mental Disorders; Population; Epidemiology; Chronic Disease; Comorbidity
21.  Associations between DSM-IV mental disorders and subsequent COPD diagnosis 
Journal of psychosomatic research  2015;79(5):333-339.
COPD and mental disorder comorbidity is commonly reported, although findings are limited by substantive weaknesses. Moreover, few studies investigate mental disorder as a risk for COPD onset. This research aims to investigate associations between current (12-month) DSM-IV mental disorders and COPD, associations between temporally prior mental disorders and subsequent COPD diagnosis, and cumulative effect of multiple mental disorders.
Data were collected using population surveys of 19 countries (n = 52,095). COPD diagnosis was assessed by self-report of physician's diagnosis. The World Mental Health-Composite International Diagnostic Interview (WMH-CIDI) was used to retrospectively assess lifetime prevalence and age at onset of 16 DSM-IV disorders. Adjusting for age, gender, smoking, education, and country, survival analysis estimated associations between first onset of mental disorder and subsequent COPD diagnosis.
COPD and several mental disorders were concurrently associated across the 12-month period (ORs 1.5–3.8). When examining associations between temporally prior disorders and COPD, all but two mental disorders were associated with COPD diagnosis (ORs 1.7–3.5). After comorbidity adjustment, depression, generalized anxiety disorder, and alcohol abuse were significantly associated with COPD (ORs 1.6–1.8). There was a substantive cumulative risk of COPD diagnosis following multiple mental disorders experienced over the lifetime. Conclusions: Mental disorder prevalence is higher in those with COPD than those without COPD. Over time, mental disorders are associated with subsequent diagnosis of COPD; further, the risk is cumulative for multiple diagnoses. Attention should be given to the role of mental disorders in the pathogenesis of COPD using prospective study designs.
PMCID: PMC5120393  PMID: 26526305
Alcohol abuse; Anxiety disorders; Comorbidity; COPD; Depression
22.  Pediatric-Onset and Adult-Onset Separation Anxiety Disorder Across Countries in the World Mental Health Survey 
The American journal of psychiatry  2015;172(7):647-656.
The age-at-onset criterion for separation anxiety disorder was removed in DSM-5, making it timely to examine the epidemiology of separation anxiety disorder as a disorder with onsets spanning the life course, using cross-country data.
The sample included 38,993 adults in 18 countries in the World Health Organization (WHO) World Mental Health Surveys. The WHO Composite International Diagnostic Interview was used to assess a range of DSM-IV disorders that included an expanded definition of separation anxiety disorder allowing onsets in adulthood. Analyses focused on prevalence, age at onset, comorbidity, predictors of onset and persistence, and separation anxiety-related role impairment.
Lifetime separation anxiety disorder prevalence averaged 4.8% across countries (interquartile range [25th–75th percentiles]=1.4%–6.4%), with 43.1% of lifetime onsets occurring after age 18. Significant time-lagged associations were found between earlier separation anxiety disorder and subsequent onset of internalizing and externalizing DSM-IV disorders and conversely between these disorders and subsequent onset of separation anxiety disorder. Other consistently significant predictors of lifetime separation anxiety disorder included female gender, retrospectively reported childhood adversities, and lifetime traumatic events. These predictors were largely comparable for separation anxiety disorder onsets in childhood, adolescence, and adulthood and across country income groups. Twelve-month separation anxiety disorder prevalence was considerably lower than lifetime prevalence (1.0% of the total sample; interquartile range=0.2%–1.2%). Severe separation anxiety-related 12-month role impairment was significantly more common in the presence (42.4%) than absence (18.3%) of 12-month comorbidity.
Separation anxiety disorder is a common and highly comorbid disorder that can have onset across the lifespan. Childhood adversity and lifetime trauma are important antecedents, and adverse effects on role function make it a significant target for treatment.
PMCID: PMC5116912  PMID: 26046337
23.  Associations between DSM-IV mental disorders and subsequent non-fatal, self-reported stroke 
Journal of psychosomatic research  2015;79(2):130-136.
To examine the associations between a wide range of mental disorders and subsequent onset of stroke. Lifecourse timing of stroke was examined using retrospectively reconstructed data from cross-sectional surveys.
Data from the World Mental Health Surveys were accessed. This data was collected from general population surveys over 17 countries of 87,250 adults. The Composite International Diagnostic Interview retrospectively assessed lifetime prevalence and age at onset of DSM-IV mental disorders. A weighted subsample (n = 45,288), was used for analysis in the present study. Survival analyses estimated associations between first onset of mental disorders and subsequent stroke onset.
Bivariate models showed that 12/16 mental disorders were associated with subsequent stroke onset (ORs ranging from 1.6 to 3.8). However, after adjustment for mental disorder comorbidity and smoking, only significant relationships between depression and stroke (OR 1.3) and alcohol abuse and stroke (OR 1.5) remained. Among females, having a bipolar disorder was also associated with increased stroke incidence (OR 2.1). Increasing number of mental disorders was associated with stroke onset in a dose–response fashion (OR 3.3 for 5+ disorders).
Depression and alcohol abuse may have specific associations with incidence of non-fatal stroke. General severity of psychopathology may be a more important predictor of non-fatal stroke onset. Mental health treatment should be considered as part of stroke risk prevention. Limitations of retrospectively gathered cross sectional surveys design mean further research on the links between mental health and stroke incidence is warranted.
PMCID: PMC4621960  PMID: 26094010
Depression; Alcohol abuse; Stroke; Comorbidity
24.  Cross-National Comparisons of Sex Differences in Opportunities to Use Alcohol or Drugs, and the Transitions to Use 
Substance use & misuse  2011;46(9):1169-1178.
Sex differences in opportunities to use alcohol or drugs, and transition to use, were investigated in 15 surveys, in 2001–2004 (Europe 6; Americas 3; Africa 2, Asia 3; Oceania 1). The paper focuses on 18–29 year olds (N = 9,873). The World Mental Health Survey Initiative oversaw the surveys; each country obtained its own funding. A complex picture emerged with different results for alcohol and for drugs and for opportunity to use and the transition to use. Sex differences in opportunity to use alcohol were small except in Lebanon and Nigeria, whereas for drugs, the largest differences were in Mexico and Colombia.
PMCID: PMC4809203  PMID: 21417555
alcohol drinking; street drugs; sex factors; epidemiology; natural history; opportunity to use
25.  Sub-threshold Post Traumatic Stress Disorder in the WHO World Mental Health Surveys 
Biological psychiatry  2014;77(4):375-384.
Although only a minority of people exposed to a traumatic event (TE) develops PTSD, symptoms not meeting full PTSD criteria are common and often clinically significant. Individuals with these symptoms have sometimes been characterized as having sub-threshold PTSD, but no consensus exists on the optimal definition of this term. Data from a large cross-national epidemiological survey are used to provide a principled basis for such a definition.
The WHO World Mental Health (WMH) Surveys administered fully-structured psychiatric diagnostic interviews to community samples in 13 countries containing assessments of PTSD associated with randomly selected TEs. Focusing on the 23,936 respondents reporting lifetime TE exposure, associations of approximated DSM-5 PTSD symptom profiles with six outcomes (distress-impairment, suicidality, comorbid fear-distress disorders, PTSD symptom duration) were examined to investigate implications of different sub-threshold definitions.
Although consistently highest distress-impairment, suicidality, comorbidity, and symptom duration were observed among the 3.0% of respondents with DSM-5 PTSD than other symptom profiles, the additional 3.6% of respondents meeting two or three of DSM-5 Criteria BE also had significantly elevated scores for most outcomes. The proportion of cases with threshold versus sub-threshold PTSD varied depending on TE type, with threshold PTSD more common following interpersonal violence and sub-threshold PTSD more common following events happening to loved ones.
Sub-threshold DSM-5 PTSD is most usefully defined as meeting two or three of the DSM-5 Criteria B-E. Use of a consistent definition is critical to advance understanding of the prevalence, predictors, and clinical significance of sub-threshold PTSD.
PMCID: PMC4194258  PMID: 24842116
posttraumatic stress disorder; PTSD; partial PTSD; sub-threshold PTSD; nosology; epidemiology

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