PurposeSiblings of probands with depressive and anxiety disorders are at increased risk for psychopathology, but little is known about how risk factors operate within families to increase... Show morePurposeSiblings of probands with depressive and anxiety disorders are at increased risk for psychopathology, but little is known about how risk factors operate within families to increase psychopathology for siblings. We examined the additional impact of psychosocial risk factors in probands—on top of or in combination with those in siblings—on depressive/anxious psychopathology in siblings.MethodsThe sample included 636 participants (Mage = 49.7; 62.4% female) from 256 families, each including a proband with lifetime depressive and/or anxiety disorders and their sibling(s) (N = 380 proband-sibling pairs). Sixteen psychosocial risk factors were tested. In siblings, depressive and anxiety disorders were determined with standardized psychiatric interviews; symptom severity was measured using self-report questionnaires. Analyses were performed with mixed-effects models accounting for familial structure.ResultsIn siblings, various psychosocial risk factors (female gender, low income, childhood trauma, poor parental bonding, being single, smoking, hazardous alcohol use) were associated with higher symptomatology and likelihood of disorder. The presence of the same risk factor in probands was independently associated (low income, being single) with higher symptomatology in siblings or moderated (low education, childhood trauma, hazardous alcohol use)—by reducing its strength—the association between the risk factor and symptomatology in siblings. There was no additional impact of risk factors in probands on likelihood of disorder in siblings.ConclusionOur findings demonstrate the importance of weighing psychosocial risk factors within a family context, as it may provide relevant information on the risk of affective psychopathology for individuals. Show less
Background: Investigating siblings of probands with affective disorders enables the identification of psychopathology-related risk features. Leveraging data from an older adult sample, as compared... Show moreBackground: Investigating siblings of probands with affective disorders enables the identification of psychopathology-related risk features. Leveraging data from an older adult sample, as compared to most previous sibling studies, enabled us to study more definitive clinical profiling across the lifespan. We examined prevalence of depressive/anxiety disorders in siblings, proband-sibling resemblance in psychopathology-related features, and whether unaffected siblings showed higher levels of these features than healthy controls. Methods: The sample (N=929; Mage=50.6) consisted of 256 probands with lifetime depressive and/or anxiety disorders, their 380 siblings, and 293 healthy controls without affected relatives. Fifteen psychopathologyrelated features were investigated across four domains: mental health symptoms, social vulnerabilities, cognitive vulnerabilities, and personality. Results: Lifetime disorders were present in 50.3% of siblings. Prevalence was 2-3 times higher than Dutch population frequencies. We found small to medium probandsibling resemblance across psychopathology-related features (rho=0.10-0.32). Unaffected siblings reported poorer interpersonal functioning and more negative life events, childhood trauma, and rumination than healthy controls. Limitations: Due to the cross-sectional study design, the directionality of effects cannot be determined. No inferences can be made about potential differences in familial resemblance in psychopathology-related features between high- and low-risk families. Conclusions: Siblings of probands with affective disorders are at higher risk for depressive/anxiety disorders. Even when unaffected, still show higher psychosocial vulnerability than healthy controls. Nevertheless, the only modest proband-sibling resemblance across psychopathology-related features suggests that individual mechanisms differentiate clinical trajectories across the lifespan. Identification of these mechanisms is crucial to improve resilience in subjects with familial risk. Show less
Background: Brothers and sisters growing up together share a large proportion of their genes and rearing environment. However, some siblings thrive whereas others struggle. This study investigated... Show moreBackground: Brothers and sisters growing up together share a large proportion of their genes and rearing environment. However, some siblings thrive whereas others struggle. This study investigated family-wide childhood bonding experiences with mother and father, in addition to individual-specific recollections, in relation to current depressive and anxiety symptom levels in adulthood. We examined whether extraversion and internal locus of control (iLoC) had a protective effect in this.Methods: The sample consisted of 256 families with at least one lifetime depressed or anxious person (N = 596; ages 20-78). Multilevel modeling with cross-level interactions was used.Results: Adult siblings showed moderate to high agreement in their childhood parental bonding (PB) recollections. Over-and-above the association between individual-specific recollections of PB and adult internalizing symptoms, family-wide poor PB was additionally linked to elevated symptom levels. Within families characterized by poor maternal bonding persons with an iLoC were relatively less anxious (but not less depressed), whereas extraversion was not protective in this context.Limitation: Although evidence exists that poor childhood PB has an impact on (adult) psychopathology, causality cannot be determined and possible recall bias of PB should be noted. Moreover, next to their moderating effects, extraversion and LoC may also act as mediators.Conclusions: Our findings extend prior work by demonstrating the importance of siblings' childhood PB experiences next to a person's own recollections when investigating adult internalizing symptoms, while also elucidating individual differences within families. Show less
