Strength is negatively associated with depression and accounts for some of the sex difference A replication and extension

Background Depression occurs about twice as often in women as in men, a disparity that remains poorly understood. In a previous publication, Hagen and Rosenstrom predicted and found that grip strength, a highly sexually dimorphic index of physical formidability, mediated much of the effect of sex on depression. Striking results like this are more likely to be published than null results, potentially biasing the scientific record. It is therefore critical to replicate and extend them. Methodology Using new data from the 2013-14 cycle of the National Health and Nutrition Examination Survey, a nationally representative sample of US households (n = 3650), we replicated models of the effect of sex and grip strength on depression reported in Hagen and Rosenstrom, along with additional potential confounds and a new detailed symptom-level exploration. Results Overall, the effects from the original paper were reproduced although with smaller effect sizes. Grip strength mediated 38% of the effect of sex on depression, compared to 63% in Hagen and Rosenstrom. These results were extended with findings that grip strength had a stronger association with some depression symptoms, like suicidality, low interest and low mood than with other symptoms, like appetite changes. Conclusions Grip strength is negatively associated with depression, especially its cognitive-affective symptoms, controlling for numerous possible confounds. Although many factors influence depression, few of these reliably occur cross-culturally in a sex-stratified manner and so are unlikely to explain the well-established, cross-cultural sex difference in depression. The sex difference in upper body strength occurs in all populations and is therefore a candidate evolutionary explanation for some of the sex difference in depression. Lay summary: Why are women at twice the risk of developing depression as men? Depression typically occurs during social conflicts, such as physical or sexual abuse. Physically strong individuals can often single-handedly resolve conflicts in their favor, whereas physically weaker individuals often need help from others. We argue that depression is a credible cry for help. Because men generally have greater strength than women, we argue that men may be more likely to resolve conflicts using physical formidability and women to signal others for help. We find that higher grip strength is associated with lower depression, particularly symptoms like feeling down or thoughts of suicide and that strength accounts for part of the sex difference in rates of depression.Peer reviewe

Associations between specific depressive symptoms and psychosocial functioning in psychotherapy

Background: Psychotherapy for depression aims to reduce symptoms and to improve psychosocial functioning. We examined whether some symptoms are more important than others in the association between depression and functioning over the course of psychotherapy treatment.Methods: We studied associations between specific symptoms of depression (PHQ-9) and change in social and occupational functioning (SOFAS), both with structural equation models (considering liabilities of depression and each specific symptom) and with logistic regression models (considering the risk for individual patients). The study sample consisted of adult patients (n symbolscript 771) from the Finnish Psychotherapy Quality Registry (FPQR) who completed psychotherapy treatment between September 2018 and September 2021.Results: Based on our results of logistic regression analyses and SEM models, the baseline measures of depression symptoms were not associated with changes in functioning. Changes in depressed mood or hopelessness, problems with sleep, feeling tired, and feeling little interest or pleasure were associated with improved func-tioning during psychotherapy. The strongest evidence for symptom-specific effects was found for the symptom of depressed mood or hopelessness. Limitations: Due to our naturalistic study design containing only two measurement points, we were unable to study the causal relationship between symptoms and functioning. Conclusions: Changes in certain symptoms during psychotherapy may affect functioning independently of un-derlying depression. Knowledge about the dynamics between symptoms and functioning could be used in treatment planning or implementation. Depressed mood or hopelessness appears to have a role in the dynamic relationship between depression and functioning.Peer reviewe

Genetic and Environmental Structure of DSM-IV Criteria for Antisocial Personality Disorder: A Twin Study

Results from previous studies on DSM-IV and DSM-5 Antisocial Personality Disorder (ASPD) have suggested that the construct is etiologically multidimensional. To our knowledge, however, the structure of genetic and environmental influences in ASPD has not been examined using an appropriate range of biometric models and diagnostic interviews. The 7 ASPD criteria (section A) were assessed in a population-based sample of 2794 Norwegian twins by a structured interview for DSM-IV personality disorders. Exploratory analyses were conducted at the phenotypic level. Multivariate biometric models, including both independent and common pathways, were compared. A single phenotypic factor was found, and the best-fitting biometric model was a single-factor common pathway model, with common-factor heritability of 51% (95% CI 40–67%). In other words, both genetic and environmental correlations between the ASPD criteria could be accounted for by a single common latent variable. The findings support the validity of ASPD as a unidimensional diagnostic construct

Specific Antisocial and Borderline Personality Disorder Criteria and General Substance Use : A Twin Study

Antisocial (ASPD) and borderline (BPD) personality disorders (PDs) are associated with increased risk for substance use. They are "specific" risk factors among PDs in that they withstand adjusting for the other PDs, whereas the reverse does not hold. Specificity is a classic sign of causation. This empirical work addresses 3 further problems that can undermine causal inferences in personality and substance-use research: hierarchical nature of etiologic factors in psychiatry, imperfectly operationalized PD criteria, and possible genetic or environmental confounding, as seen in lack of "etiologic continuity." We used exploratory structural equation bifactor modeling and biometric models to mitigate these problems. The participants were Norwegian adult twins of ages 19-36 years (N = 2,801). Criteria for Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), PDs were assessed using a structured interview. General substance-use risk was indicated by World Health Organization Composite International Diagnostic Interviewed alcohol use disorder and illicit drug use, and by self-reported regular smoking. A general risk factor for all criteria of both ASPD and BPD was the strongest individual correlate of general substance use and showed etiologic continuity, though just 3 specific PD criteria could predict substance use to the same extent. The findings indicate that a broad latent factor for both ASPD and BPD may be a specific and a genetically and environmentally unconfounded risk factor for substance use. Substance-use treatment research might benefit from attending to transdiagnostic models of ASPD, BPD, and related behavioral disinhibition.Peer reviewe

Joint factorial structure of psychopathology and personality

Background Normative and pathological personality traits have rarely been integrated into a joint large-scale structural analysis with psychiatric disorders, although a recent study suggested they entail a common individual differences continuum. Methods We explored the joint factor structure of 11 psychiatric disorders, five personality-disorder trait domains (DSM-5 Section III), and five normative personality trait domains (the 'Big Five') in a population-based sample of 2796 Norwegian twins, aged 19-46. Results Three factors could be interpreted: (i) a general risk factor for all psychopathology, (ii) a risk factor specific to internalizing disorders and traits, and (iii) a risk factor specific to externalizing disorders and traits. Heritability estimates for the three risk factor scores were 48% (95% CI 41-54%), 35% (CI 28-42%), and 37% (CI 31-44%), respectively. All 11 disorders had uniform loadings on the general factor (congruence coefficient of 0.991 with uniformity). Ignoring sign and excluding the openness trait, this uniformity of factor loadings held for all the personality trait domains and all disorders (congruence 0.983). Conclusions Based on our findings, future research should investigate joint etiologic and transdiagnostic models for normative and pathological personality and other psychopathology.Peer reviewe

Explaining the sex difference in depression with a unified bargaining model of anger and depression

Peer reviewe

Social anxiety disorder is a risk factor for alcohol use problems in the National Comorbidity Surveys

Background: According to the self-medication and biopsychosocial models, individuals with social anxiety disorder (SAD) are at increased risk of developing an alcohol use disorder (AUD) as alcohol represents a maladaptive coping mechanism for some sufferers of SAD. The SAD-to-AUD causation was earlier supported in Norwegian longitudinal twin data and later questioned using longitudinal data from the USA.Methods: We re-analyzed partly the same USA-based data (National Comorbidity Surveys, n = 5001), conducting theoretical and simulation analyses on different formulations of temporality and using real-data Logistic regression analysis to investigate whether baseline SAD was associated with AUD at the follow-up.Results: Upon proper analysis of temporality, SAD preceded AUD. Specifically, SAD was the only one of the seven anxiety disorders that predicted 10-year later AUD after adjusting for all other anxiety disorders and AUD at the baseline (odds ratio was 1.70% and 95% confidence interval 1.12-2.57). SAD was also associated with incident AUD (OR = 1.64, 95% CI = 1.14-2.37). We provide formal, simulation-based, and data-based arguments on how certain flawed models of incidence attenuate the temporal association. Conclusions: We demonstrated temporality and specificity in SAD-to-AUD association, which are considered signs of causation. We further identified and discussed problems in previous statistical analyses with different conclusions. Our findings add support for models positing causal effects of SAD on AUD, such as the self-medication and biopsychosocial models. The available evidence suggests that treating SAD should incur better chances of preventing AUD compared to treating other anxiety disorders, which lack comparable evidence on causation.Peer reviewe

Borderline personality disorder and depression severity predict suicidal outcomes : A six-month prospective cohort study of depression, bipolar depression, and borderline personality disorder

BackgroundSuicide risk is high in patients with major depressive disorder (MDD), bipolar disorder (BD) and borderline personality disorder (BPD). Whether risk levels of and risk factors for suicidal ideation (SI) and suicide attempts (SA) are similar or different in these disorders remains unclear, as few directly comparative studies exist. The relationship of short-term changes in depression severity and SI is underinvestigated, and might differ across groups, for example, between BPD and non-BPD patients.MethodsWe followed, for 6 months, a cohort of treatment-seeking, major depressive episode (MDE) patients in psychiatric care (original n = 124), stratified into MDE/MDD, MDE/BD and MDE/BPD subcohorts. We examined risks of suicide-related outcomes and their risk factors prospectively. We examined the covariation of SI and depression over time with biweekly online modified Patient Health Questionnaire 9 surveys and analysed this relationship through multi-level modelling.ResultsRisk of SA in BPD (22.2%) was higher than non-BPD (4.23%) patients. In regression models, BPD severity was correlated with risk of SA and clinically significant SI. During follow-up, mean depression severity and changes in depression symptoms were associated with SI risk regardless of diagnosis.ConclusionsConcurrent BPD in depression seems predictive for high risk of SA. Severity of BPD features is relevant for assessing risk of SA and SI in MDE. Changes in depressive symptoms indicate concurrent changes in risk of SI. BPD status at intake can index risk for future SA, whereas depressive symptoms appear a useful continuously monitored risk index.Peer reviewe

Adaptive and non-adaptive models of depression: A comparison using register data on antidepressant medication during divorce

Divorce is associated with an increased probability of a depressive episode, but the causation of events remains unclear. Adaptive models of depression propose that depression is a social strategy in part, whereas non-adaptive models tend to propose a diathesis-stress mechanism. We compare an adaptive evolutionary model of depression to three alternative non-adaptive models with respect to their ability to explain the temporal pattern of depression around the time of divorce. Register-based data (304,112 individuals drawn from a random sample of 11% of Finnish people) on antidepressant purchases is used as a proxy for depression. This proxy affords an unprecedented temporal resolution (a 3-monthly prevalence estimates over 10 years) without any bias from non-compliance, and it can be linked with underlying episodes via a statistical model. The evolutionary-adaptation model (all time periods with risk of divorce are depressogenic) was the best quantitative description of the data. The non-adaptive stress-relief model (period before divorce is depressogenic and period afterwards is not) provided the second best quantitative description of the data. The peak-stress model (periods before and after divorce can be depressogenic) fit the data less well, and the stress-induction model (period following divorce is depressogenic and the preceding period is not) did not fit the data at all. The evolutionary model was the most detailed mechanistic description of the divorce-depression link among the models, and the best fit in terms of predicted curvature; thus, it offers most rigorous hypotheses for further study. The stress-relief model also fit very well and was the best model in a sensitivity analysis, encouraging development of more mechanistic models for that hypothesis

The p factor of psychopathology and personality in middle childhood : genetic and gestational risk factors

A correction has been issued for this article: DOI: https://doi.org/10.1017/S0033291723000879BackgroundA joint, hierarchical structure of psychopathology and personality has been reported in adults but should also be investigated at earlier ages, as psychopathology often develops before adulthood. Here, we investigate the joint factor structure of psychopathology and personality in eight-year-old children, estimate factor heritability and explore external validity through associations with established developmental risk factors. MethodsPhenotypic and biometric exploratory factor analyses with bifactor rotation on genetically informative data from the Norwegian Mother, Father, and Child Cohort (MoBa) study. The analytic sub-sample comprised 10 739 children (49% girls). Mothers reported their children's symptoms of depression (Short Moods and Feelings Questionnaire), anxiety (Screen for Anxiety Related Disorders), attention-deficit/hyperactivity disorder inattention and hyperactivity, oppositional-defiant disorder, conduct disorder (Parent/Teacher Rating Scale for Disruptive Behavior Disorders), and Big Five personality (short Hierarchical Personality Inventory for Children). Developmental risk factors (early gestational age and being small for gestational age) were collected from the Medical Birth Registry. ResultsGoodness-of-fit indices favored a p factor model with three residual latent factors interpreted as negative affectivity, positive affectivity, and antagonism, whereas psychometric indices favored a one-factor model. ADE solutions fitted best, and regression analyses indicated a negative association between gestational age and the p factor, for both the one- and four-factor solutions. ConclusionCorrelations between normative and pathological traits in middle childhood mostly reflect one heritable and psychometrically interpretable p factor, although optimal fit to data required less interpretable residual latent factors. The association between the p factor and low gestational age warrants further study of early developmental mechanisms.Peer reviewe