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2.  Data Gathering Bias: Trait Vulnerability to Psychotic Symptoms? 
PLoS ONE  2015;10(7):e0132442.
Jumping to conclusions (JTC) is associated with psychotic disorder and psychotic symptoms. If JTC represents a trait, the rate should be (i) increased in people with elevated levels of psychosis proneness such as individuals diagnosed with borderline personality disorder (BPD), and (ii) show a degree of stability over time.
The JTC rate was examined in 3 groups: patients with first episode psychosis (FEP), BPD patients and controls, using the Beads Task. PANSS, SIS-R and CAPE scales were used to assess positive psychotic symptoms. Four WAIS III subtests were used to assess IQ.
A total of 61 FEP, 26 BPD and 150 controls were evaluated. 29 FEP were revaluated after one year. 44% of FEP (OR = 8.4, 95% CI: 3.9–17.9) displayed a JTC reasoning bias versus 19% of BPD (OR = 2.5, 95% CI: 0.8–7.8) and 9% of controls. JTC was not associated with level of psychotic symptoms or specifically delusionality across the different groups. Differences between FEP and controls were independent of sex, educational level, cannabis use and IQ. After one year, 47.8% of FEP with JTC at baseline again displayed JTC.
JTC in part reflects trait vulnerability to develop disorders with expression of psychotic symptoms.
PMCID: PMC4493127  PMID: 26147948
3.  The Influence of Perceived Stress on Cortical Reactivity: A Proof-Of-Principle Study 
PLoS ONE  2015;10(6):e0129220.
The aim of this study was to investigate how perceived stress may affect electroencephalographical (EEG) activity in a stress paradigm in a sample of 76 healthy participants. EEG activity was analyzed using multilevel modeling, allowing estimation of nested effects (EEG time segments within subjects). The stress paradigm consisted of a 3-minute pre-stimulus stress period and a 2-minute post-stimulus phase. At t=3 minutes, a single electrical stimulus was delivered. Participants were unaware of the precise moment of stimulus delivery and its intensity level. In the EEG time course of alpha activity, a stronger increase was observed during the post-stimulus period as compared to the pre-stimulus period. An opposite time course effect was apparent for gamma activity. Both effects were in line with a priori expectations and support the validity of this experimental EEG-stress paradigm. Secondly, we investigated whether interaction effects of stress and coping, as measured with the Perceived Stress Scale-10 questionnaire (PSS-10), could be demonstrated. A higher perceived stress score was accompanied by a greater increase in delta- and theta-activity during the post-stimulus phase, compared to low scores. In contrast, low coping capacity was associated with a stronger decrease in slow beta, fast beta and gamma activity during the post-stimulus phase. The results of the present article may be interpreted as proof-of-principle that EEG stress-related activity depends on the level of subjectively reported perceived stress. The inclusion of psychosocial variables measuring coping styles as well as stress-related personality aspects permits further examination of the interconnection between mind and body and may inform on the process of transformation from acute to chronic stress.
PMCID: PMC4475054  PMID: 26090882
4.  From Affective Experience to Motivated Action: Tracking Reward-Seeking and Punishment-Avoidant Behaviour in Real-Life 
PLoS ONE  2015;10(6):e0129722.
Many of the decisions and actions in everyday life result from implicit learning processes. Important to psychopathology are, for example, implicit reward-seeking and punishment-avoidant learning processes. It is known that when specific actions get associated with a rewarding experience, such as positive emotions, that this will increase the likelihood that an organism will engage in similar actions in the future. Similarly, when actions get associated with punishing experiences, such as negative emotions, this may reduce the likelihood that the organism will engage in similar actions in the future. This study examines whether we can observe these implicit processes prospectively in the flow of daily life. If such processes take place then we expect that current behaviour can be predicted by how similar behaviour was experienced (in terms of positive and negative affect) at previous measurement moments. This was examined in a sample of 621 female individuals that had participated in an Experience Sampling data collection. Measures of affect and behaviour were collected at 10 semi-random moments of the day for 5 consecutive days. It was examined whether affective experience that was paired with certain behaviours (physical activity and social context) at previous measurements modified the likelihood to show similar behaviours at next measurement moments. Analyses were performed both at the level of observations (a time scale with units of ± 90 min) and at day level (a time scale with units of 24 h). As expected, we found that affect indeed moderated the extent to which previous behaviour predicted similar behaviour later in time, at both beep- and day-level. This study showed that it is feasible to track reward-seeking and punishment-avoidant behaviour prospectively in humans in the flow of daily life. This opens up a new toolbox to examine processes determining goal-oriented behaviour in relation to psychopathology in humans.
PMCID: PMC4472779  PMID: 26087323
5.  EEG Changes Due to Experimentally Induced 3G Mobile Phone Radiation 
PLoS ONE  2015;10(6):e0129496.
The aim of this study was to investigate whether a 15-minute placement of a 3G dialing mobile phone causes direct changes in EEG activity compared to the placement of a sham phone. Furthermore, it was investigated whether placement of the mobile phone on the ear or the heart would result in different outcomes. Thirty-one healthy females participated. All subjects were measured twice: on one of the two days the mobile phone was attached to the ear, the other day to the chest. In this single-blind, cross-over design, assessments in the sham phone condition were conducted directly preceding and following the mobile phone exposure. During each assessment, EEG activity and radiofrequency radiation were recorded jointly. Delta, theta, alpha, slowbeta, fastbeta, and gamma activity was computed. The association between radiation exposure and the EEG was tested using multilevel random regression analyses with radiation as predictor of main interest. Significant radiation effects were found for the alpha, slowbeta, fastbeta, and gamma bands. When analyzed separately, ear location of the phone was associated with significant results, while chest placement was not. The results support the notion that EEG alterations are associated with mobile phone usage and that the effect is dependent on site of placement. Further studies are required to demonstrate the physiological relevance of these findings.
PMCID: PMC4459698  PMID: 26053854
6.  Experience Sampling-Based Personalized Feedback and Positive Affect: A Randomized Controlled Trial in Depressed Patients 
PLoS ONE  2015;10(6):e0128095.
Positive affect (PA) plays a crucial role in the development, course, and recovery of depression. Recently, we showed that a therapeutic application of the experience sampling method (ESM), consisting of feedback focusing on PA in daily life, was associated with a decrease in depressive symptoms. The present study investigated whether the experience of PA increased during the course of this intervention.
Multicentre parallel randomized controlled trial. An electronic random sequence generator was used to allocate treatments.
University, two local mental health care institutions, one local hospital.
102 pharmacologically treated outpatients with a DSM-IV diagnosis of major depressive disorder, randomized over three treatment arms.
Six weeks of ESM self-monitoring combined with weekly PA-focused feedback sessions (experimental group); six weeks of ESM self-monitoring combined with six weekly sessions without feedback (pseudo-experimental group); or treatment as usual (control group).
Main outcome
The interaction between treatment allocation and time in predicting positive and negative affect (NA) was investigated in multilevel regression models.
102 patients were randomized (mean age 48.0, SD 10.2) of which 81 finished the entire study protocol. All 102 patients were included in the analyses. The experimental group did not show a significant larger increase in momentary PA during or shortly after the intervention compared to the pseudo-experimental or control groups (χ2 (2) =0.33, p=.846). The pseudo-experimental group showed a larger decrease in NA compared to the control group (χ2 (1) =6.29, p=.012).
PA-focused feedback did not significantly impact daily life PA during or shortly after the intervention. As the previously reported reduction in depressive symptoms associated with the feedback unveiled itself only after weeks, it is conceivable that the effects on daily life PA also evolve slowly and therefore were not captured by the experience sampling procedure immediately after treatment.
Trial Registration NTR1974
PMCID: PMC4452775  PMID: 26034983
7.  Does the Brain Detect 3G Mobile Phone Radiation Peaks? An Explorative In-Depth Analysis of an Experimental Study 
PLoS ONE  2015;10(5):e0125390.
This study aimed to investigate whether third generation mobile phone radiation peaks result in event related potentials. Thirty-one healthy females participated. In this single-blind, cross-over design, a 15 minute mobile phone exposure was compared to two 15 minute sham phone conditions, one preceding and one following the exposure condition. Each participant was measured on two separate days, where mobile phone placement was varied between the ear and heart. EEG activity and radiofrequency radiation were recorded jointly. Epochs of 1200ms, starting 200ms before and lasting until 1000ms after the onset of a radiation peak, were extracted from the exposure condition. Control epochs were randomly selected from the two sham phone conditions. The main a-priori hypothesis to be tested concerned an increase of the area in the 240-500ms post-stimulus interval, in the exposure session with ear-placement. Using multilevel regression analyses the placement*exposure interaction effect was significant for the frontal and central cortical regions, indicating that only in the mobile phone exposure with ear-placement an enlarged cortical reactivity was found. Post-hoc analyses based on visual inspection of the ERPs showed a second significantly increased area between 500-1000ms post-stimulus for almost every EEG location measured. It was concluded that, when a dialing mobile phone is placed on the ear, its radiation, although unconsciously, is electrically detected by the brain. The question of whether or not this cortical reactivity results in a negative health outcome has to be answered in future longitudinal experiments.
PMCID: PMC4427287  PMID: 25962168
8.  The transdiagnostic dimension of psychosis: implications for psychiatric nosology and research 
If psychosis is a transdiagnostic dimension, the expression of which is governed by a dynamic set of contextual and emotional factors that are amenable to treatment, current approaches in psychiatric nosology and therapeutic research may need to be revised. The dominant approach to date is to clinically and conceptually situate psychotic symptoms in the construct of schizophrenia. However, schizophrenia, which has a lifetime prevalence of 1%, only represents the poor outcome fraction of a much broader spectrum of psychotic disorders which have a lifetime prevalence of 3.5%. Therefore, research findings in schizophrenia may reflect mechanisms of prognosis rather than fundamental associations with psychosis and other symptom domains per se. Similarly, the discovery that up to 30% of individuals with non-psychotic common mental disorders have subthreshold psychotic symptoms that situate them on the transdiagnostic dimension of psychosis – and which impact clinical severity and treatment response – indicates that the rigid separation between ‘psychotic’ and ‘non-psychotic’ hampers both clinical practice and research. Diagnostic manuals in psychiatry would benefit from a system of transdiagnostic dimensions, including a transdiagnostic dimension of psychosis. Introduction of transdiagnostic dimensions allows for a system combining a nomothetic (i.e., group-specific) categorical diagnosis with an idiographic (i.e., person-specific) combination of dimensional scores. The advantage of such a system is that it encourages consideration of how symptoms dynamically interact with each other in a network of psychopathology, and of how this network is impacted by the social world.
PMCID: PMC4466847  PMID: 26120256
psychosis; diagnosis; nosology; epidemiology; schizophrenia; transdiagnostic
9.  Default Mode Network Connectivity as a Function of Familial and Environmental Risk for Psychotic Disorder 
PLoS ONE  2015;10(3):e0120030.
Research suggests that altered interregional connectivity in specific networks, such as the default mode network (DMN), is associated with cognitive and psychotic symptoms in schizophrenia. In addition, frontal and limbic connectivity alterations have been associated with trauma, drug use and urban upbringing, though these environmental exposures have never been examined in relation to DMN functional connectivity in psychotic disorder.
Resting-state functional MRI scans were obtained from 73 patients with psychotic disorder, 83 non-psychotic siblings of patients with psychotic disorder and 72 healthy controls. Posterior cingulate cortex (PCC) seed-based correlation analysis was used to estimate functional connectivity within the DMN. DMN functional connectivity was examined in relation to group (familial risk), group × environmental exposure (to cannabis, developmental trauma and urbanicity) and symptomatology.
There was a significant association between group and PCC connectivity with the inferior parietal lobule (IPL), the precuneus (PCu) and the medial prefrontal cortex (MPFC). Compared to controls, patients and siblings had increased PCC connectivity with the IPL, PCu and MPFC. In the IPL and PCu, the functional connectivity of siblings was intermediate to that of controls and patients. No significant associations were found between DMN connectivity and (subclinical) psychotic/cognitive symptoms. In addition, there were no significant interactions between group and environmental exposures in the model of PCC functional connectivity.
Increased functional connectivity in individuals with (increased risk for) psychotic disorder may reflect trait-related network alterations. The within-network “connectivity at rest” intermediate phenotype was not associated with (subclinical) psychotic or cognitive symptoms. The association between familial risk and DMN connectivity was not conditional on environmental exposure.
PMCID: PMC4366233  PMID: 25790002
10.  The Association between Negative Symptoms, Psychotic Experiences and Later Schizophrenia: A Population-Based Longitudinal Study 
PLoS ONE  2015;10(3):e0119852.
Psychotic experiences are common in the general population, and predict later psychotic illness. Much less is known about negative symptoms in the general population.
This study utilized a sample of 4,914 Israel-born individuals aged 25–34 years who were screened for psychopathology in the 1980's. Though not designed to specifically assess negative symptoms, data were available on 9 self-report items representing avolition and social withdrawal, and on 5 interviewer-rated items assessing speech deficits, flat affect and poor hygiene. Psychotic experiences were assessed using the False Beliefs and Perceptions subscale of the Psychiatric Epidemiology Research Interview. Psychiatric hospitalization was ascertained 24 years later using a nation-wide psychiatric hospitalization registry.
After removing subjects with diagnosable psychotic disorders at baseline, 20.2% had at least one negative symptom. Negative symptoms were associated with increased risk of later schizophrenia only in the presence of strong (frequent) psychotic experiences (OR = 13.0, 9% CI: 2.1–79.4).
Negative symptoms are common in the general population, though the majority of people with negative symptoms do not manifest a clinically diagnosed psychiatric disorder. Negative symptoms and psychotic experiences critically depend on each other’s co-occurrence in increasing risk for later schizophrenia.
PMCID: PMC4351950  PMID: 25748557
11.  Time-Lagged Moment-to-Moment Interplay Between Negative Affect and Paranoia: New Insights in the Affective Pathway to Psychosis 
Schizophrenia Bulletin  2013;40(2):278-286.
Evidence suggests that affect plays a role in the development of psychosis but the underlying mechanism requires further investigation. This study examines the moment-to-moment dynamics between negative affect (NA) and paranoia prospectively in daily life. A female general population sample (n = 515) participated in an experience sampling study. Time-lagged analyses between increases in momentary NA and subsequent momentary paranoia were examined. The impact of childhood adversity, stress sensitivity (impact of momentary stress on momentary NA), and depressive symptoms on these time-lagged associations, as well as associations with follow-up self-reported psychotic symptoms (Community Assessment of Psychic Experiences and the Symptom Checklist-90-Revised) were investigated. Moments of NA increase resulted in a significant increase in paranoia over 180 subsequent minutes. Both stress sensitivity and depressive symptoms impacted on the transfer of NA to paranoia. Stress sensitivity moderated the level of increase in paranoia during the initial NA increase, while depressive symptoms increased persistence of paranoid feelings from moment to moment. Momentary paranoia responses to NA increases were associated with follow-up psychotic symptoms. Examination of microlevel momentary experience may thus yield new insights into the mechanism underlying co-occurrence of altered mood states and psychosis. Knowledge of the underlying mechanism is required in order to determine source and place where remediation should occur.
PMCID: PMC3932075  PMID: 23407984
momentary assessment methodology; stress; childhood adversity; psychotic symptoms; depressive symptoms
12.  Psychopathological Mechanisms Linking Childhood Traumatic Experiences to Risk of Psychotic Symptoms: Analysis of a Large, Representative Population-Based Sample 
Schizophrenia Bulletin  2014;40(Suppl 2):S123-S130.
Background: Different psychological models of trauma-induced psychosis have been postulated, often based on the observation of “specific” associations between particular types of childhood trauma (CT) and particular psychotic symptoms or the co-occurrence of delusions and hallucinations. However, the actual specificity of these associations remains to be tested. Methods: In 2 population-based studies with comparable methodology (Netherlands Mental Health Survey and Incidence Study-1 [NEMESIS-1] and NEMESIS-2, N = 13 722), trained interviewers assessed CT, psychotic symptoms, and other psychopathology. Specificity of associations was assessed with mixed-effects regression models with multiple outcomes, a statistical method suitable to examine specificity of associations in case of multiple correlated outcomes. Results: Associations with CT were strong and significant across the entire range of psychotic symptoms, without evidence for specificity in the relationship between particular trauma variables and particular psychotic experiences (PEs). Abuse and neglect were both associated with PEs (ORabuse: 2.12, P < .001; ORneglect: 1.96, P < .001), with no large or significant difference in effect size. Intention-to-harm experiences showed stronger associations with psychosis than CT without intent (χ2 = 58.62, P < .001). Most trauma variables increased the likelihood of co-occurrence of delusions and hallucinations rather than either symptom in isolation. Discussion: Intention to harm is the key component linking childhood traumatic experiences to psychosis, most likely characterized by co-occurrence of hallucinations and delusions, indicating buildup of psychotic intensification, rather than specific psychotic symptoms in isolation. No evidence was found to support psychological theories regarding specific associations between particular types of CT and particular psychotic symptoms.
PMCID: PMC3934395  PMID: 24562491
epidemiology; childhood adversity; psychosis
13.  Biological Insights From 108 Schizophrenia-Associated Genetic Loci 
Ripke, Stephan | Neale, Benjamin M | Corvin, Aiden | Walters, James TR | Farh, Kai-How | Holmans, Peter A | Lee, Phil | Bulik-Sullivan, Brendan | Collier, David A | Huang, Hailiang | Pers, Tune H | Agartz, Ingrid | Agerbo, Esben | Albus, Margot | Alexander, Madeline | Amin, Farooq | Bacanu, Silviu A | Begemann, Martin | Belliveau, Richard A | Bene, Judit | Bergen, Sarah E | Bevilacqua, Elizabeth | Bigdeli, Tim B | Black, Donald W | Bruggeman, Richard | Buccola, Nancy G | Buckner, Randy L | Byerley, William | Cahn, Wiepke | Cai, Guiqing | Campion, Dominique | Cantor, Rita M | Carr, Vaughan J | Carrera, Noa | Catts, Stanley V | Chambert, Kimberley D | Chan, Raymond CK | Chan, Ronald YL | Chen, Eric YH | Cheng, Wei | Cheung, Eric FC | Chong, Siow Ann | Cloninger, C Robert | Cohen, David | Cohen, Nadine | Cormican, Paul | Craddock, Nick | Crowley, James J | Curtis, David | Davidson, Michael | Davis, Kenneth L | Degenhardt, Franziska | Del Favero, Jurgen | Demontis, Ditte | Dikeos, Dimitris | Dinan, Timothy | Djurovic, Srdjan | Donohoe, Gary | Drapeau, Elodie | Duan, Jubao | Dudbridge, Frank | Durmishi, Naser | Eichhammer, Peter | Eriksson, Johan | Escott-Price, Valentina | Essioux, Laurent | Fanous, Ayman H | Farrell, Martilias S | Frank, Josef | Franke, Lude | Freedman, Robert | Freimer, Nelson B | Friedl, Marion | Friedman, Joseph I | Fromer, Menachem | Genovese, Giulio | Georgieva, Lyudmila | Giegling, Ina | Giusti-Rodríguez, Paola | Godard, Stephanie | Goldstein, Jacqueline I | Golimbet, Vera | Gopal, Srihari | Gratten, Jacob | de Haan, Lieuwe | Hammer, Christian | Hamshere, Marian L | Hansen, Mark | Hansen, Thomas | Haroutunian, Vahram | Hartmann, Annette M | Henskens, Frans A | Herms, Stefan | Hirschhorn, Joel N | Hoffmann, Per | Hofman, Andrea | Hollegaard, Mads V | Hougaard, David M | Ikeda, Masashi | Joa, Inge | Julià, Antonio | Kahn, René S | Kalaydjieva, Luba | Karachanak-Yankova, Sena | Karjalainen, Juha | Kavanagh, David | Keller, Matthew C | Kennedy, James L | Khrunin, Andrey | Kim, Yunjung | Klovins, Janis | Knowles, James A | Konte, Bettina | Kucinskas, Vaidutis | Kucinskiene, Zita Ausrele | Kuzelova-Ptackova, Hana | Kähler, Anna K | Laurent, Claudine | Lee, Jimmy | Lee, S Hong | Legge, Sophie E | Lerer, Bernard | Li, Miaoxin | Li, Tao | Liang, Kung-Yee | Lieberman, Jeffrey | Limborska, Svetlana | Loughland, Carmel M | Lubinski, Jan | Lönnqvist, Jouko | Macek, Milan | Magnusson, Patrik KE | Maher, Brion S | Maier, Wolfgang | Mallet, Jacques | Marsal, Sara | Mattheisen, Manuel | Mattingsdal, Morten | McCarley, Robert W | McDonald, Colm | McIntosh, Andrew M | Meier, Sandra | Meijer, Carin J | Melegh, Bela | Melle, Ingrid | Mesholam-Gately, Raquelle I | Metspalu, Andres | Michie, Patricia T | Milani, Lili | Milanova, Vihra | Mokrab, Younes | Morris, Derek W | Mors, Ole | Murphy, Kieran C | Murray, Robin M | Myin-Germeys, Inez | Müller-Myhsok, Bertram | Nelis, Mari | Nenadic, Igor | Nertney, Deborah A | Nestadt, Gerald | Nicodemus, Kristin K | Nikitina-Zake, Liene | Nisenbaum, Laura | Nordin, Annelie | O’Callaghan, Eadbhard | O’Dushlaine, Colm | O’Neill, F Anthony | Oh, Sang-Yun | Olincy, Ann | Olsen, Line | Van Os, Jim | Pantelis, Christos | Papadimitriou, George N | Papiol, Sergi | Parkhomenko, Elena | Pato, Michele T | Paunio, Tiina | Pejovic-Milovancevic, Milica | Perkins, Diana O | Pietiläinen, Olli | Pimm, Jonathan | Pocklington, Andrew J | Powell, John | Price, Alkes | Pulver, Ann E | Purcell, Shaun M | Quested, Digby | Rasmussen, Henrik B | Reichenberg, Abraham | Reimers, Mark A | Richards, Alexander L | Roffman, Joshua L | Roussos, Panos | Ruderfer, Douglas M | Salomaa, Veikko | Sanders, Alan R | Schall, Ulrich | Schubert, Christian R | Schulze, Thomas G | Schwab, Sibylle G | Scolnick, Edward M | Scott, Rodney J | Seidman, Larry J | Shi, Jianxin | Sigurdsson, Engilbert | Silagadze, Teimuraz | Silverman, Jeremy M | Sim, Kang | Slominsky, Petr | Smoller, Jordan W | So, Hon-Cheong | Spencer, Chris C A | Stahl, Eli A | Stefansson, Hreinn | Steinberg, Stacy | Stogmann, Elisabeth | Straub, Richard E | Strengman, Eric | Strohmaier, Jana | Stroup, T Scott | Subramaniam, Mythily | Suvisaari, Jaana | Svrakic, Dragan M | Szatkiewicz, Jin P | Söderman, Erik | Thirumalai, Srinivas | Toncheva, Draga | Tosato, Sarah | Veijola, Juha | Waddington, John | Walsh, Dermot | Wang, Dai | Wang, Qiang | Webb, Bradley T | Weiser, Mark | Wildenauer, Dieter B | Williams, Nigel M | Williams, Stephanie | Witt, Stephanie H | Wolen, Aaron R | Wong, Emily HM | Wormley, Brandon K | Xi, Hualin Simon | Zai, Clement C | Zheng, Xuebin | Zimprich, Fritz | Wray, Naomi R | Stefansson, Kari | Visscher, Peter M | Adolfsson, Rolf | Andreassen, Ole A | Blackwood, Douglas HR | Bramon, Elvira | Buxbaum, Joseph D | Børglum, Anders D | Cichon, Sven | Darvasi, Ariel | Domenici, Enrico | Ehrenreich, Hannelore | Esko, Tõnu | Gejman, Pablo V | Gill, Michael | Gurling, Hugh | Hultman, Christina M | Iwata, Nakao | Jablensky, Assen V | Jönsson, Erik G | Kendler, Kenneth S | Kirov, George | Knight, Jo | Lencz, Todd | Levinson, Douglas F | Li, Qingqin S | Liu, Jianjun | Malhotra, Anil K | McCarroll, Steven A | McQuillin, Andrew | Moran, Jennifer L | Mortensen, Preben B | Mowry, Bryan J | Nöthen, Markus M | Ophoff, Roel A | Owen, Michael J | Palotie, Aarno | Pato, Carlos N | Petryshen, Tracey L | Posthuma, Danielle | Rietschel, Marcella | Riley, Brien P | Rujescu, Dan | Sham, Pak C | Sklar, Pamela | St Clair, David | Weinberger, Daniel R | Wendland, Jens R | Werge, Thomas | Daly, Mark J | Sullivan, Patrick F | O’Donovan, Michael C
Nature  2014;511(7510):421-427.
Schizophrenia is a highly heritable disorder. Genetic risk is conferred by a large number of alleles, including common alleles of small effect that might be detected by genome-wide association studies. Here, we report a multi-stage schizophrenia genome-wide association study of up to 36,989 cases and 113,075 controls. We identify 128 independent associations spanning 108 conservatively defined loci that meet genome-wide significance, 83 of which have not been previously reported. Associations were enriched among genes expressed in brain providing biological plausibility for the findings. Many findings have the potential to provide entirely novel insights into aetiology, but associations at DRD2 and multiple genes involved in glutamatergic neurotransmission highlight molecules of known and potential therapeutic relevance to schizophrenia, and are consistent with leading pathophysiological hypotheses. Independent of genes expressed in brain, associations were enriched among genes expressed in tissues that play important roles in immunity, providing support for the hypothesized link between the immune system and schizophrenia.
PMCID: PMC4112379  PMID: 25056061
14.  Familial Liability to Psychosis Is Associated With Attenuated Dopamine Stress Signaling in Ventromedial Prefrontal Cortex 
Schizophrenia Bulletin  2013;40(1):66-77.
Objective: Patients diagnosed with a psychotic disorder and their first-degree relatives display increased reactivity to stress. Theory predicts that experience of psychosocial stress is associated both with ventromedial prefrontal and mesolimbic dopamine neurotransmission. However, while there is evidence of aberrant striatal dopamine processing in psychotic disorder, the role of the prefrontal cortex remains under-researched. This study aimed at investigating stress-induced in vivo dopamine release in ventromedial prefrontal cortex (vmPFC) of individuals at familial risk for psychosis. Method: Fourteen healthy first-degree relatives of patients with a diagnosis of psychotic disorder and 10 control subjects underwent a single dynamic positron emission tomography (PET) scanning session after intravenous administration of 183.2 (SD = 7.6) MBq [18F]fallypride. Psychosocial stress was initiated at 100min postinjection using a computerized mental arithmetic task with social evaluative threat components. PET data were analyzed using the linearized simplified reference region model. Regression analyses were performed to compare the spatial extent of task-related ligand displacement between control subjects and relatives and to find how it related to self-rated experiences of psychosocial stress and psychosis. Results: First-degree relatives displayed hyporeactive dopamine signaling in the vmPFC in response to stress. Increased levels of subjectively rated stress were associated with increased intensity of psychotic experiences. This effect was particularly pronounced in first-degree relatives. Conclusion: Although previous studies have hypothesized a role for prefrontal dopamine dysfunction in psychosis, this study, to our knowledge, is the first in vivo human imaging study showing attenuated (ie, hyporeactive) dopamine stress neuromodulation in vmPFC of individuals at familial risk for psychosis.
PMCID: PMC3885294  PMID: 23363687
schizophrenia; positron emission tomography; neuromodulation; relatives; mesolimbic; salience
15.  Testing an mHealth Momentary Assessment Routine Outcome Monitoring Application: A Focus on Restoration of Daily Life Positive Mood States 
PLoS ONE  2014;9(12):e115254.
Routine Outcome Monitoring (ROM) is used as a means to enrich the process of treatment with feedback on patient outcomes, facilitating patient involvement and shared decision making. While traditional ROM measures focus on retrospective accounts of symptoms, novel mHealth technology makes it possible to collect real life, in-the-moment ambulatory data that allow for an ecologically valid assessment of personalized and contextualized emotional and behavioural adjustment in the flow daily life (mROM).
In a sample of 34 patients with major depressive disorder, treated with antidepressants, the combined effect of treatment and natural course was examined over a period of 18 weeks with Ecological Momentary Assessment (EMA). EMA consisted of repeated, within-subject, mini-measurements of experience (eg positive affect, negative affect, medication side effects) and context (eg stressors, situations, activities) at 10 unselected semi-random moments per day, for a period of six days, repeated three times over the 18-week period (baseline, week 6 and week 18).
EMA measures of emotional and behavioural adjustment were sensitive to the effects of treatment and natural course over the 18-week period, particularly EMA measures focussing on positive mood states and the ability to use natural rewards (impact of positive events on positive mood states), with standardized effect sizes of 0.4–0.5. EMA measures of activities, social interaction, stress-sensitivity and negative mood states were also sensitive to change over time.
This study supports the use of mROM as a means to involve the patient in the process of needs assessment and treatment. EMA data are meaningful to the patient, as they reflect daily life circumstances. Assessment of treatment response with mROM data allows for an interpretation of the effect of treatment at the level of daily life emotional and social adjustment – as an index of health, obviating the need for an exclusive focus on traditional measures of ‘sickness’.
PMCID: PMC4267819  PMID: 25513813
16.  Hyper-Theory-of-Mind in Children with Psychotic Experiences 
PLoS ONE  2014;9(11):e113082.
Alterations in Theory-of-Mind (ToM) are associated with psychotic disorder. In addition, studies in children have documented that alterations in ToM are associated with Psychotic Experiences (PE). Our aim was to examine associations between an exaggerated type of ToM (HyperToM) and PE in children. Children with this type of alteration in ToM infer mental states when none are obviously suggested, and predict behaviour on the basis of these erroneous beliefs. Individuals with HyperToM do not appear to have a conceptual deficit (i.e. lack of representational abilities), but rather they apply their theory of the minds of others in an incorrect or biased way.
Hypotheses were tested in two studies with two independent samples: (i) a general population sample of 1630 Danish children aged 11–12 years, (ii) a population-based sample of 259 Dutch children aged 12–13 years, pertaining to a case-control sampling frame of children with auditory verbal hallucinations. Multinomial regression analyses were carried out to investigate the associations between PE and ToM and HyperToM respectively. Analyses were adjusted for gender and proxy measures of general intelligence.
Low ToM score was significantly associated with PE in sample I (OR = 1.6 95%CI 1.1–2.3 χ2(4) = 12.42 p = 0.010), but not in sample II (OR = 0.9 95%CI 0.5–1.8 χ2(3) = 7.13 p = 0.816). HyperToM was significantly associated with PE both in sample I (OR = 1.8, 95%CI 1.2–2.7 χ2(3) = 10.11 p = 0.006) and II (OR = 4.6, 95%CI 1.3–16.2 χ2(2) = 7.56 p = 0.018). HyperToM was associated particularly with paranoid delusions in both sample I (OR = 2.0, 95%CI: 1.1–3.7% χ2(4) = 9.93 p = 0.021) and II (OR = 6.2 95%CI: 1.7–23.6% χ2(4) = 9.90 p = 0.044).
Specific alterations in ToM may be associated with specific types of psychotic experiences. HyperToM may index risk for developing psychosis and paranoid delusions in particular.
PMCID: PMC4232592  PMID: 25397582
17.  Attenuated Psychosis Syndrome in DSM-5 
Schizophrenia research  2013;150(1):31-35.
Despite advances in the treatment of schizophrenia over the past half-century, the illness is frequently associated with a poor outcome. This is principally related to the late identification and intervention in the course of the illness by which time patients have experienced a substantial amount of socio-occupational decline that can be difficult to reverse. The emphasis has therefore shifted to defining psychosis-risk syndromes and evaluating treatments that can prevent transition to psychosis in these ultra-high risk groups. To consider the appropriateness of adding psychosis risk syndrome to our diagnostic nomenclature, the Psychotic Disorders Workgroup extensively reviewed all available data, consulted a range of experts, and carefully considered the variety of expert and public comments on the topic. It was clear that reliable methods were available to define a syndrome characterized by sub-threshold psychotic symptoms (in severity or duration) and which was associated with a very significant increase in the risk of development of a full-fledged psychotic disorder (schizophrenia spectrum, psychotic mood disorder, other psychotic disorder) within the next year. At the same time, the majority of individuals with “attenuated psychotic symptoms” had one or more other current psychiatric comorbid conditions (usually mood or anxiety disorders, substance use disorder; Fusar-Poli 2012) and exhibited a range of psychiatric outcomes other than conversion to psychosis (significant proportions either fully recover or develop some other psychiatric disorder with a minority developing a psychotic disorder). Whereas the reliability of the diagnosis is well established in academic and research settings, it was found to be less so in community and other clinical settings. Furthermore, the nosological relationship of Attenuated Psychosis Syndrome (APS) to schizotypal personality disorder and other psychiatric conditions was unclear. Further study will hopefully resolve these questions. The Workgroup decided to recommend the inclusion of Attenuated Psychosis Syndrome as a category in the appendix (Section 3) of DSM-5 as a condition for further study.
PMCID: PMC3778120  PMID: 23773295
18.  Horizon 2020 Priorities in Clinical Mental Health Research: Results of a Consensus-Based ROAMER Expert Survey 
Within the ROAMER project, which aims to provide a Roadmap for Mental Health Research in Europe, a two-stage Delphi survey among 86 European experts was conducted in order to identify research priorities in clinical mental health research. Expert consensus existed with regard to the importance of three challenges in the field of clinical mental health research: (1) the development of new, safe and effective interventions for mental disorders; (2) understanding the mechanisms of disease in order to be able to develop such new interventions; and (3) defining outcomes (an improved set of outcomes, including alternative outcomes) to use for clinical mental health research evaluation. Proposed actions involved increasing the utilization of tailored approaches (personalized medicine), developing blended eHealth/mHealth decision aids/guidance tools that help the clinician to choose between various treatment modalities, developing specific treatments in order to better target comorbidity and (further) development of biological, psychological and psychopharmacological interventions. The experts indicated that addressing these priorities will result in increased efficacy and impact across Europe; with a high probability of success, given that Europe has important strengths, such as skilled academics and a long research history. Finally, the experts stressed the importance of creating funding and coordinated networking as essential action needed in order to target the variety of challenges in clinical mental health research.
PMCID: PMC4211014  PMID: 25337940
clinical mental health research; Delphi survey; priorities; Horizon 2020
19.  Novel Evidence That Attributing Affectively Salient Signal to Random Noise Is Associated with Psychosis 
PLoS ONE  2014;9(7):e102520.
We wished to replicate evidence that an experimental paradigm of speech illusions is associated with psychotic experiences. Fifty-four patients with a first episode of psychosis (FEP) and 150 healthy subjects were examined in an experimental paradigm assessing the presence of speech illusion in neutral white noise. Socio-demographic, cognitive function and family history data were collected. The Positive and Negative Syndrome Scale (PANSS) was administered in the patient group and the Structured Interview for Schizotypy-Revised (SIS-R), and the Community Assessment of Psychic Experiences (CAPE) in the control group. Patients had a much higher rate of speech illusions (33.3% versus 8.7%, ORadjusted: 5.1, 95% CI: 2.3–11.5), which was only partly explained by differences in IQ (ORadjusted: 3.4, 95% CI: 1.4–8.3). Differences were particularly marked for signals in random noise that were perceived as affectively salient (ORadjusted: 9.7, 95% CI: 1.8–53.9). Speech illusion tended to be associated with positive symptoms in patients (ORadjusted: 3.3, 95% CI: 0.9–11.6), particularly affectively salient illusions (ORadjusted: 8.3, 95% CI: 0.7–100.3). In controls, speech illusions were not associated with positive schizotypy (ORadjusted: 1.1, 95% CI: 0.3–3.4) or self-reported psychotic experiences (ORadjusted: 1.4, 95% CI: 0.4–4.6). Experimental paradigms indexing the tendency to detect affectively salient signals in noise may be used to identify liability to psychosis.
PMCID: PMC4097069  PMID: 25020079
20.  Towards Horizon 2020: challenges and advances for clinical mental health research – outcome of an expert survey 
The size and increasing burden of disease due to mental disorders in Europe poses substantial challenges to its population and to the health policy of the European Union. This warrants a specific research agenda concerning clinical mental health research as one of the cornerstones of sustainable mental health research and health policy in Europe. The aim of this research was to identify the top priorities needed to address the main challenges in clinical research for mental disorders.
The research was conducted as an expert survey and expert panel discussion during a scientific workshop.
Eighty-nine experts in clinical research and representing most European countries participated in this survey. Identified top priorities were the need for new intervention studies, understanding the diagnostic and therapeutic implications of mechanisms of disease, and research in the field of somatic-psychiatric comorbidity. The “subjectivity gap” between basic neuroscience research and clinical reality for patients with mental disorders is considered the main challenge in psychiatric research, suggesting that a shift in research paradigms is required.
Innovations in clinical mental health research should bridge the gap between mechanisms underlying novel therapeutic interventions and the patient experience of mental disorder and, if present, somatic comorbidity. Clinical mental health research is relatively underfunded and should receive specific attention in Horizon 2020 funding programs.
PMCID: PMC4085314  PMID: 25061300
clinical research; mental health; randomized clinical trials; Horizon 2020; expert survey; challenge; research agenda; Europe
21.  How to Boost Positive Interpretations? A Meta-Analysis of the Effectiveness of Cognitive Bias Modification for Interpretation 
PLoS ONE  2014;9(6):e100925.
The current meta-analysis explores the strength of effects of cognitive bias modification training for interpretation bias (CBM-I) on positive (i.e., adaptive) interpretations and mood as well as the training and sample characteristics influencing these effects. Data-bases were searched with the key words “interpret* bias AND training” and “interpret* bias AND modif*”. Reference lists of identified articles were checked and authors of identified articles were contacted for further relevant articles and unpublished data. Studies were reviewed for inclusion with eligibility criteria being that the study (a) aimed to target interpretation biases through any kind of training, (b) assessed mood and/or interpretation bias as outcome measures, (c) allocated individuals to training conditions at random, and (d) recruited adult samples. A meta-analytic multilevel mixed-effects model was employed to assess standardized mean changes in interpretation bias, negative mood, and emotional reactivity. In addition, several training and sample characteristics were explored for their potential to enhance benign training effectiveness. On average, benign CBM-I resulted in an increase in positive interpretation bias (p<.01) and a decrease in negative mood state (p<.001), but did not affect emotional reactivity. These effects were not consistently different from control conditions with no or neutral training. However, within benign training conditions imagery instructions and more training sessions were related to larger cognitive and mood effects, whereas feedback about training performance and inclusion of non-benign training items (instead of including benign items only) boosted cognitive effects only. Finally, training was more effective in women (cognitive and mood effects) and presumably samples with symptomatic emotional dysregulation (cognitive effects). Although the effects of emotional dysregulation and number of training sessions could not well be distinguished, there is an indication that when used with imagery instructions and more training sessions, benign CBM-I can be employed as a useful complementary treatment to usual psychotherapies.
PMCID: PMC4072710  PMID: 24968234
22.  Epigenetic Genes and Emotional Reactivity to Daily Life Events: A Multi-Step Gene-Environment Interaction Study 
PLoS ONE  2014;9(6):e100935.
Recent human and animal studies suggest that epigenetic mechanisms mediate the impact of environment on development of mental disorders. Therefore, we hypothesized that polymorphisms in epigenetic-regulatory genes impact stress-induced emotional changes. A multi-step, multi-sample gene-environment interaction analysis was conducted to test whether 31 single nucleotide polymorphisms (SNPs) in epigenetic-regulatory genes, i.e. three DNA methyltransferase genes DNMT1, DNMT3A, DNMT3B, and methylenetetrahydrofolate reductase (MTHFR), moderate emotional responses to stressful and pleasant stimuli in daily life as measured by Experience Sampling Methodology (ESM). In the first step, main and interactive effects were tested in a sample of 112 healthy individuals. Significant associations in this discovery sample were then investigated in a population-based sample of 434 individuals for replication. SNPs showing significant effects in both the discovery and replication samples were subsequently tested in three other samples of: (i) 85 unaffected siblings of patients with psychosis, (ii) 110 patients with psychotic disorders, and iii) 126 patients with a history of major depressive disorder. Multilevel linear regression analyses showed no significant association between SNPs and negative affect or positive affect. No SNPs moderated the effect of pleasant stimuli on positive affect. Three SNPs of DNMT3A (rs11683424, rs1465764, rs1465825) and 1 SNP of MTHFR (rs1801131) moderated the effect of stressful events on negative affect. Only rs11683424 of DNMT3A showed consistent directions of effect in the majority of the 5 samples. These data provide the first evidence that emotional responses to daily life stressors may be moderated by genetic variation in the genes involved in the epigenetic machinery.
PMCID: PMC4072714  PMID: 24967710
23.  Almost All Antipsychotics Result in Weight Gain: A Meta-Analysis 
PLoS ONE  2014;9(4):e94112.
Antipsychotics (AP) induce weight gain. However, reviews and meta-analyses generally are restricted to second generation antipsychotics (SGA) and do not stratify for duration of AP use. It is hypothesised that patients gain more weight if duration of AP use is longer.
A meta-analysis was conducted of clinical trials of AP that reported weight change. Outcome measures were body weight change, change in BMI and clinically relevant weight change (7% weight gain or loss). Duration of AP-use was stratified as follows: ≤6 weeks, 6–16 weeks, 16–38 weeks and >38 weeks. Forest plots stratified by AP as well as by duration of use were generated and results were summarised in figures.
307 articles met inclusion criteria. The majority were AP switch studies. Almost all AP showed a degree of weight gain after prolonged use, except for amisulpride, aripiprazole and ziprasidone, for which prolonged exposure resulted in negligible weight change. The level of weight gain per AP varied from discrete to severe. Contrary to expectations, switch of AP did not result in weight loss for amisulpride, aripiprazole or ziprasidone. In AP-naive patients, weight gain was much more pronounced for all AP.
Given prolonged exposure, virtually all AP are associated with weight gain. The rational of switching AP to achieve weight reduction may be overrated. In AP-naive patients, weight gain is more pronounced.
PMCID: PMC3998960  PMID: 24763306
24.  Histone Deacetylase 2 in the Mouse Hippocampus: Attenuation of Age-Related Increase by Caloric Restriction 
Current Alzheimer research  2013;10(8):868-876.
The aging process in the hippocampus is associated with aberrant epigenetic marks, such as DNA methylation and histone tail alterations. Recent evidence suggests that caloric restriction (CR) can potentially delay the aging process, while upregulation of antioxidants may also have a beneficial effect in this respect. We have recently observed that CR attenuates age-related changes in the levels of the epigenetic molecules DNA methyltransferase 3a, 5-methylcytidine (5-mC) and 5-hydroxymethylcytosine in the mouse hippocampus while overexpression of the antioxidant Cu/Zn superoxide dismutase 1 (SOD1) does not. However, the impact of aging on the levels of histone-modifying enzymes such as histone deacetylase 2 (HDAC2) in the hippocampus has not been studied in much detail. Here, we investigated immunoreactivity (IR) of HDAC2 in three subregions of the hippocampus (dentate gyrus, CA3 and CA1-2) of mice taken from large cohorts of aging wild-type and transgenic mice overexpressing normal human SOD1, which were kept under normal diet or CR from weaning onwards. Independent from the genotype, aging (between 12 and 24 months) increased levels of HDAC2 IR in the hippocampus. Moreover, CR prevented this age-related increase, particularly in the CA3 and CA1-2 subregions, while SOD1 overexpression did not. Quantitative image analyses showed that HDAC2 IR correlated positively with 5-mC IR while these markers were shown to colocalize in the nucleus of hippocampal cells. Together with recent literature reports, these findings suggest that altered levels of epigenetic regulatory proteins including HDAC2 regulate age-related changes in the mouse hippocampus and that CR may prevent these age-related changes.
PMCID: PMC3966721  PMID: 24093534
Aging; epigenesis; histone deacetylase 2 (HDAC2); caloric restriction; hippocampus
25.  Brain-Derived Neurotrophic Factor/FK506-Binding Protein 5 Genotype by Childhood Trauma Interactions Do Not Impact on Hippocampal Volume and Cognitive Performance 
PLoS ONE  2014;9(3):e92722.
In the development of psychotic symptoms, environmental and genetic factors may both play a role. The reported association between childhood trauma and psychotic symptoms could therefore be moderated by single nucleotide polymorphisms (SNPs) associated with the stress response, such as FK506-binding protein 5 (FKBP5) and brain-derived neurotrophic factor (BDNF). Recent studies investigating childhood trauma by SNP interactions have inconsistently found the hippocampus to be a potential target underlying these interactions. Therefore, more detailed modelling of these effects, using appropriate covariates, is required. We examined whether BDNF/FKBP5 and childhood trauma interactions affected two proxies of hippocampal integrity: (i) hippocampal volume and (ii) cognitive performance on a block design (BD) and delayed auditory verbal task (AVLT). We also investigated whether the putative interaction was different for patients with a psychotic disorder (n = 89) compared to their non-psychotic siblings (n = 95), in order to elicit possible group-specific protective/vulnerability effects. SNPs were rs9296158, rs4713916, rs992105, rs3800373 (FKBP5) and rs6265 (BDNF). In the combined sample, no BDNF/FKBP5 by childhood trauma interactions were apparent for either outcome, and BDNF/FKBP5 by childhood trauma interactions were not different for patients and siblings. The omission of drug use and alcohol consumption sometimes yielded false positives, greatly affected explained error and influenced p-values. The consistent absence of any significant BDNF/FKBP5 by childhood trauma interactions on assessments of hippocampal integrity suggests that the effect of these interactions on psychotic symptoms is not mediated by hippocampal integrity. The importance of appropriate statistical designs and inclusion of relevant covariates should be carefully considered.
PMCID: PMC3962453  PMID: 24658422

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