The associations of CAs with persistence of DSM-IV/CIDI disorders
Two-thirds of the CAs are significantly associated with greater persistence of disorders in bivariate backward recurrence models that examine one CA at a time and that pool across the 20 DSM-IV/CIDI disorders. () These ORs are all weak in substantive terms (1.1-1.3), indicating that persistence in a given year is only modestly higher among people with than without a history of CAs. Furthermore, most significant bivariate ORs become insignificant in a multivariate model that includes all CAs. The two CAs that remain significant in the multivariate additive model (physical abuse and sexual abuse) have weak ORs (1.1-1.2). In addition, only a weak dose-response relationship exists between number of CAs and disorder persistence in the multivariate model of number of CAs, with ORs of 1.3-1.4 for respondents who experienced a high number of CAs (compared to respondents who experienced no CAs). We can nonetheless reject the hypothesis that the two significant ORs occurred by chance in the set of 12 (χ212 = 63.1, p < .001) as well as the hypothesis that the 12 ORs do not differ significantly among themselves (χ211= 41.6, p < .001). The latter result means that we would have under-estimated the associations of CAs with persistence by using a simple 0-12 summary count measure.
Bivariate and multivariate associations (odds ratios) between childhood adversities (CAs) and the persistence of DSM-IV/CIDI disorders (N=10,915)a
The most complex model we considered, a multivariate interactive model, includes separate predictors for type of CA (i.e., one predictor for each of the 12 CAs) and number of CAs (i.e., separate predictors for respondents who were exposed to exactly one, exactly two, exactly three…etc. CAs) and distinguishes between MFF CAs and other CAs. This model shows that type (χ27 = 31.1, p < .001) but not number (χ26 = 6.0, p = .43) of MFF CAs is significantly associated with disorder persistence, while neither type (χ25 = 4.6, p = .47) nor number (χ25 = 3.2, p = .36) of non-MFF CAs is associated with persistence. The significant MFF CAs include parental mental illness, physical abuse, sexual abuse, and neglect, each of which has a modestly elevated OR (1.2-1.2). The ORs associated with number of MFF CAs become increasingly smaller and less than 1.0 in this model as number increases, documenting significant sub-additive interactions among the MFF CAs (i.e., that the joint effects of multiple MFF CAs are significantly less than the product of the ORs associated with the individual CAs in the cluster).
Disaggregation by type of disorder
Disaggregation of the final model by type of disorder reveals differential associations of CAs with persistence of mood, anxiety, disruptive behavior, and substance disorders. () Type of MFF CA is significantly associated with persistence of mood, anxiety, and substance disorders (χ27 = 19.8-52.8, p = .006-<.001), but not disruptive behavior disorders (χ27 = 8.5, p = .29). All MFF CAs other than parental criminality are associated with mood, anxiety, or substance disorders, with significant ORs in the range 1.2-1.9. Only two of these ORs vary significantly across the three types of disorders: (i) a higher OR of parental substance disorders with respondent substance disorders (1.5) than the other disorders (1.0-1.1); and (ii) a higher OR of physical abuse with mood disorders (1.9) than the other disorders (1.1-1.3). Type of Non-MFF CA is associated with persistence of disruptive behavior disorders (χ25 = 12.9, p = .025), but not mood, anxiety, or substance disorders (χ25 = 1.0-6.0, p = .31-.96), although none of the individual CAs is significantly associated with disruptive behavior disorders. A test of the joint associations of the 21 type and number of CA variables with disorder persistence across the four disorder classes is significant (χ263 = 95.7, p = .005), indicating differential associations by disorder type.
Multivariate associations (odds ratios) between childhood adversities (CAs) and the persistence of DSM-IV/CIDI classes of disorders based on a simple interactive model (N=10,915)a
The ORs for number of MMF CAs are significantly related to persistence of mood and substance disorders (χ26 = 20.4-29.5, p = .002 - <.001), but not anxiety or disruptive behavior disorders (χ27 = 3.2-7.8, p = .25-.78). As in the aggregate model, the ORs associated with number of CAs are negative, indicating sub-additive interactions. The ORs for number of Non-MFF CAs, in comparison, are significantly related to persistence of mood disorders (χ23 = 13.5, p = .004), but not any of the other types of disorders (χ23 = 0.6-3.5, p = .33-.90), and are greater than 1.0. This means that even though none of the non-MFF CAs, when occurring alone, is significantly related to persistence of mood disorders, persistence is significantly higher among respondents who experienced a number of these CAs than respondents who experienced none.
In terms of overall strength of associations, simulations suggest that mean duration between time of interview and time of most recent episode would have increased by 4.9% for mood disorders, 0.6% for anxiety disorders, 2.1% for substance disorders, and would be largely unaffected for disruptive behavior disorders if none of the CAs had occurred and the ORs were due to causal effects of CAs.
Disaggregation by age at interview
Disaggregation of the final model by respondent age at interview shows that the significant associations described above are more pronounced in mid-life (ages 30-44 and 45-59) than either earlier (ages 18-29) or later (ages 60+) ages. () It is only in the 30-44 and 45-59 year age groups that we find significantly elevated ORs associated with type of MFF CA (χ27 = 14.3-33.3, p = .045-<.001) and significantly decreasing ORs associated with number of MFF CAs (χ26 = 12.9-15.6, p = .045-.020). As one might expect, the significant ORs associated with type are somewhat larger among respondents in the significant age range (1.2-1.4) than in the total sample (1.2). Type of Non-MFF CA is not related to disorder persistence in any age group (χ25 = 2.5-10.6, p = .78-.06), whereas number of Non-MFF CAs is significantly and positively related to persistence in the 30-44, 45-59, and 60+ age groups (χ22–3 = 6.8-238.4, p = .030-<.001). Simulations suggest that mean duration between time of interview and time of most recent episode would have increased by 1.3% among respondents in the age range 18-29, 2.6% among those ages 30-44, 1.9% among those ages 45-59, and 1.3% among those ages 60+ if none of the CAs had occurred and the ORs were due to causal effects of CAs .
Multivariate associations (odds ratios) between childhood adversities (CAs) and the persistence of DSM-IV/CIDI disorders by age at interview based on a simple interactive model (N=10,915)a
Disaggregation by the cross-classification of age at interview and type of disorder
Further disaggregation of the final model by the cross-classification of respondent age at interview and type of disorder shows further variation. (Detailed results are available on request.) The significantly elevated ORs associated with type of MFF CAs extend into the 60+ age range for mood and substance disorders and the significantly decreasing ORs associated with number of MFF CAs appear as early as in the 18-29 age range for mood and substance disorders and extend into the 60+ age range for anxiety and substance disorders. MFF CAs are more consistently significant (15% of ORs) than non-MFF CAs (2.5% of ORs), although no single MFF CA stands out as most consistently significant. Each MFF CA is significant in at least one subsample and none is significant in more than four of the 16 sub-samples created by cross-classifying the four types of disorders with the four age ranges considered here. Number of non-MFF CAs predicts greater persistence of anxiety disorders in 3 of 4 life course sub-samples. The hypothesis can be rejected that all MFF CAs have the same OR in most subsamples.
Simulated aggregate associations of CAs with time-since most recent episode
We evaluated the overall importance of CAs for disorder persistence using the simulation method described above in the Analysis Methods section. This simulation estimated the extent to which most recent episodes might have been pushed backwards in time (i.e., time since most recent episode increased) in the absence of CAs. () The mean observed time since the most recent episode under the model is 8.3 years. This mean includes respondents who were in episode at the time of interview, who were coded as having a time of 0 years since their most recent episode. This mean increases only very slightly, to 8.4 years, in the simulated data that restricts the ORs associated with CAs to 1.0. This change represents a 1.6% increase in the mean duration of time since most recent episode associated with the absence of CA effects, documenting that even though the associations of CAs with persistence are significant in a statistical sense, the overall substantive importance of CAs is quite modest. Simulations suggest that mean duration between the time of interview and time of most recent episode would have increased by no more than 12.5% (for mood disorders among respondents in the age range 30-44) in the absence of CA effects across sub-samples defined by the cross-classification of disorder and age at interview.
Simulated effects of childhood adversities on proportional increase in mean duration between time of interview and time of most recent episode in sub-samples defined by the cross-classification of disorder type and respondent age at interview