Jennifer A. Sumner

Overgeneral autobiographical memory as a predictor of the course of depression: A meta-analysis.

Overgeneral autobiographical memory (OGM) is a robust phenomenon in depression, but the extent to which OGM predicts the course of depression is not well-established. This meta-analysis synthesized data from 15 studies to examine the degree to which OGM 1) correlates with depressive symptoms at follow-up, and 2) predicts depressive symptoms at follow-up over and above initial depressive symptoms. Although the effects are small, specific and categoric/overgeneral memories generated during the Autobiographical Memory Test significantly predicted the course of depression. Fewer specific memories and more categoric/overgeneral memories were associated with higher follow-up depressive symptoms, and predicted higher follow-up symptoms over and above initial symptoms. Potential moderators were also examined. The age and clinical depression status of participants, as well as the length of follow-up between the two depressive symptom assessments, significantly moderated the predictive relationship between OGM and the course of depression. The predictive relationship between specific memories and follow-up depressive symptoms became greater with increasing age and a shorter length of follow-up, and the predictive relationship was stronger for participants with clinical depression diagnoses than for nonclinical participants. These findings highlight OGM as a predictor of the course of depression, and future studies should investigate the mechanisms underlying this relationship.

The mechanisms underlying overgeneral autobiographical memory: an evaluative review of evidence for the CaR-FA-X model.

Overgeneral autobiographical memory (OGM) has been found to be an important cognitive phenomenon with respect to depression and trauma-related psychopathology (e.g., posttraumatic stress disorder), and researchers have been interested in better understanding the factors that contribute to this proposed vulnerability factor. The most prominent model of mechanisms underlying OGM to date is Williams et al.s (2007) CaR-FA-X model. This model proposes that three processes influence OGM: capture and rumination, functional avoidance, and impaired executive control. The author reviews the current state of support for the CaR-FA-X model by evaluating 38 studies that have examined OGM and one or more mechanisms of the model. Collectively, these studies reveal robust support for associations between OGM and both rumination and impaired executive control. OGM also appears to be a cognitive avoidance strategy, and there is evidence that avoiding the retrieval of specific memories reduces distress after an aversive event, at least in the short term. Important issues that have been left unresolved are highlighted, including the nature of the capture phenomenon, the role of trauma in functional avoidance, and the developmental nature of functional avoidance. Recommendations for future research that will enhance understanding of the factors that contribute to OGM are suggested.

Trauma Exposure and Posttraumatic Stress Disorder Symptoms Predict Onset of Cardiovascular Events in Women

Background— Psychological stress is a proposed risk factor for cardiovascular disease (CVD), and posttraumatic stress disorder (PTSD), the sentinel stress-related mental disorder, occurs twice as frequently in women as men. However, whether PTSD contributes to CVD risk in women is not established. Methods and Results— We examined trauma exposure and PTSD symptoms in relation to incident CVD over a 20-year period in 49 978 women in the Nurses’ Health Study II. Proportional hazards models estimated hazard ratios and 95% confidence intervals for CVD events confirmed by additional information or medical record review (n=548, including myocardial infarction [n=277] and stroke [n=271]). Trauma exposure and PTSD symptoms were assessed by using the Brief Trauma Questionnaire and a PTSD screen. In comparison with no trauma exposure, endorsing ≥4 PTSD symptoms was associated with increased CVD risk after adjusting for age, family history, and childhood factors (hazard ratio,1.60; 95% confidence interval, 1.20–2.13). Being trauma-exposed and endorsing no PTSD symptoms was associated with elevated CVD risk (hazard ratio, 1.45; 95% confidence interval, 1.15–1.83), although being trauma-exposed and endorsing 1 to 3 PTSD symptoms was not. After adjusting for adult health behaviors and medical risk factors, this pattern of findings was maintained. Health behaviors and medical risk factors accounted for 14% of the trauma/no symptoms–CVD association and 47% of the trauma/4+ symptoms–CVD association. Conclusion— Trauma exposure and elevated PTSD symptoms may increase the risk of CVD in this population of women. These findings suggest that screening for CVD risk and reducing health risk behaviors in trauma-exposed women may be promising avenues for prevention and intervention.

An item response theory/confirmatory factor analysis of the Autobiographical Memory Test

The Autobiographical Memory Test (AMT) is used to assess the degree of specificity of autobiographical memory. The AMT usually contains cue words of both positive and negative valence, but it is unclear whether these valences form separate factors or not. Accordingly, confirmatory factor analysis assessed whether the AMT measures one overall factor, or whether different cue types are related to different factors. Results were consistent across three datasets (N = 333, N = 405, and N = 336). A one-factor model fitted each dataset well, which suggests that responses to positive and negative cues are related to the one construct. In addition, item response theory analyses showed that the AMT is most precise for people who score low on memory specificity. Implications for using the AMT with high-functioning samples are discussed.

Current psychometric and methodological issues in the measurement of overgeneral autobiographical memory

Autobiographical memory is a multifaceted construct that is related to psychopathology and other difficulties in functioning. Across many studies, a variety of methods have been used to study autobiographical memory. The relationship between overgeneral autobiographical memory (OGM) and psychopathology has been of particular interest, and many studies of this cognitive phenomenon rely on the Autobiographical Memory Test (AMT) to assess it. In this paper, we examine several methodological approaches to studying autobiographical memory, and focus primarily on methodological and psychometric considerations in OGM research. We pay particular attention to what is known about the reliability, validity, and methodological variations of the AMT. The AMT has adequate psychometric properties, but there is great variability in methodology across studies that use it. Methodological recommendations and suggestions for future studies are presented.

The Psychiatric Genomics Consortium Posttraumatic Stress Disorder Workgroup: Posttraumatic Stress Disorder Enters the Age of Large-Scale Genomic Collaboration

The development of posttraumatic stress disorder (PTSD) is influenced by genetic factors. Although there have been some replicated candidates, the identification of risk variants for PTSD has lagged behind genetic research of other psychiatric disorders such as schizophrenia, autism, and bipolar disorder. Psychiatric genetics has moved beyond examination of specific candidate genes in favor of the genome-wide association study (GWAS) strategy of very large numbers of samples, which allows for the discovery of previously unsuspected genes and molecular pathways. The successes of genetic studies of schizophrenia and bipolar disorder have been aided by the formation of a large-scale GWAS consortium: the Psychiatric Genomics Consortium (PGC). In contrast, only a handful of GWAS of PTSD have appeared in the literature to date. Here we describe the formation of a group dedicated to large-scale study of PTSD genetics: the PGC-PTSD. The PGC-PTSD faces challenges related to the contingency on trauma exposure and the large degree of ancestral genetic diversity within and across participating studies. Using the PGC analysis pipeline supplemented by analyses tailored to address these challenges, we anticipate that our first large-scale GWAS of PTSD will comprise over 10 000 cases and 30 000 trauma-exposed controls. Following in the footsteps of our PGC forerunners, this collaboration—of a scope that is unprecedented in the field of traumatic stress—will lead the search for replicable genetic associations and new insights into the biological underpinnings of PTSD.

Overgeneral autobiographical memory and chronic interpersonal stress as predictors of the course of depression in adolescents

This study investigated whether overgeneral autobiographical memory (OGM) predicts the course of depression in adolescents. As part of a larger longitudinal study of risk for emotional disorders, 55 adolescents with a past history of major depressive disorder or minor depressive disorder completed the Autobiographical Memory Test. Fewer specific memories predicted the subsequent onset of a major depressive episode (MDE) over a 16-month follow-up period, even when covarying baseline depressive symptoms. This main effect was qualified by an interaction between specific memories and chronic interpersonal stress: Fewer specific memories predicted greater risk of MDE onset over follow-up at high (but not low) levels of chronic interpersonal stress. Thus, our findings suggest that OGM, in interaction with chronic interpersonal stress, predicts the course of depression among adolescents, and highlight the importance of measuring interpersonal stress in OGM research.

Examining the mechanisms of overgeneral autobiographical memory: Capture and rumination, and impaired executive control

Overgeneral autobiographical memory (OGM) is an important cognitive phenomenon in depression, but questions remain regarding the underlying mechanisms. The CaR-FA-X model (Williams et al., 2007) proposes three mechanisms that may contribute to OGM, but little work has examined the possible additive and/or interactive effects among them. We examined two mechanisms of CaR-FA-X: capture and rumination, and impaired executive control. We analysed data from undergraduates (N=109) scoring high or low on rumination who were presented with cues of high and low self-relevance on the Autobiographical Memory Test (AMT). Executive control was operationalised as performance on both the Stroop Colour-Word Task and the Controlled Oral Word Association Test (COWAT). Hierarchical generalised linear modelling was used to predict whether participants would generate a specific memory on a trial of the AMT. Higher COWAT scores, lower rumination, and greater cue self-relevance predicted a higher probability of a specific memory. There was also a rumination×cue self-relevance interaction: Higher (vs lower) rumination was associated with a lower probability of a specific memory primarily for low self-relevant cues. We found no evidence of interactions between these mechanisms. Findings are interpreted with respect to current autobiographical memory models. Future directions for OGM mechanism research are discussed.

Largest GWAS of PTSD (N=20 070) yields genetic overlap with schizophrenia and sex differences in heritability

The Psychiatric Genomics Consortium-Posttraumatic Stress Disorder group (PGC-PTSD) combined genome-wide case–control molecular genetic data across 11 multiethnic studies to quantify PTSD heritability, to examine potential shared genetic risk with schizophrenia, bipolar disorder, and major depressive disorder and to identify risk loci for PTSD. Examining 20 730 individuals, we report a molecular genetics-based heritability estimate (h2SNP) for European-American females of 29% that is similar to h2SNP for schizophrenia and is substantially higher than h2SNP in European-American males (estimate not distinguishable from zero). We found strong evidence of overlapping genetic risk between PTSD and schizophrenia along with more modest evidence of overlap with bipolar and major depressive disorder. No single-nucleotide polymorphisms (SNPs) exceeded genome-wide significance in the transethnic (overall) meta-analysis and we do not replicate previously reported associations. Still, SNP-level summary statistics made available here afford the best-available molecular genetic index of PTSD—for both European- and African-American individuals—and can be used in polygenic risk prediction and genetic correlation studies of diverse phenotypes. Publication of summary statistics for ∼10 000 African Americans contributes to the broader goal of increased ancestral diversity in genomic data resources. In sum, the results demonstrate genetic influences on the development of PTSD, identify shared genetic risk between PTSD and other psychiatric disorders and highlight the importance of multiethnic/racial samples. As has been the case with schizophrenia and other complex genetic disorders, larger sample sizes are needed to identify specific risk loci.

Testing a Hierarchical Model of Neuroticism and Its Cognitive Facets Latent Structure and Prospective Prediction of First Onsets of Anxiety and Unipolar Mood Disorders During 3 Years in Late Adolescence

Neuroticism and several other traits have been proposed to confer vulnerability for unipolar mood disorders (UMDs) and anxiety disorders (ADs). However, it is unclear whether the associations of these vulnerabilities with these disorders are attributable to a latent variable common to all vulnerabilities, more narrow latent variables, or both. In addition, some researchers have suggested that neuroticism predicts UMDs, ADs, and substance use disorders (SUDs) with comparable strength, whereas other researchers have hypothesized that neuroticism is more strongly related to UMDs and ADs. We tested hypotheses about the factor structure of several vulnerabilities and the prospective associations of these latent variables with initial onsets of UMDs, ADs, and SUDs during a 3-year period in 547 participants recruited as high school juniors. Although a general neuroticism factor predicted SUDs, it predicted UMDs and ADs more strongly and especially predicted comorbid UMDs and ADs. There was also mixed support for specific associations involving more narrow latent vulnerabilities.