Marriage and reductions in men's alcohol, tobacco, and cannabis use.

BACKGROUND: Psychoactive substance use is lower among married compared to divorced or unmarried men; yet, the nature of this effect remains unclear because becoming and staying married is potentially confounded with substance-related background familial and individual factors, like parental divorce and personality. The authors investigated the associations between marital status and substance use; how substance use changed across the transition to marriage; and whether marriage effects were likely to be causal. METHOD: The sample included 1790 adults from male-male twin pairs from a population-based registry. Measures of marital status and alcohol, tobacco, and cannabis use came from Life History Calendars. Data were analyzed using regression, co-twin comparison, and within-person models. The latter models are tools for quasi-causal inference that control for familial and individual-level confounders. RESULTS: Married men used less alcohol, tobacco, and cannabis than men who were divorced/separated or single. In analyses of substance use across the transition to marriage, men reduced their alcohol and cannabis use both before and after marriage, but their tobacco use only after marriage. These effects were largely robust in co-twin and within-person analyses. CONCLUSIONS: Marriage was associated with substantial reductions in substance use compared to being divorced/separated or single, and these reductions began prior to marriage. The co-twin comparison and within-person models ruled out the alternative explanation that marriage effects were due to confounding background familial and individual factors. These results provide strong evidence that the social role expectations associated with marriage reduce psychoactive substance use.

Time course of panic disorder and posttraumatic stress disorder onsets.

PURPOSE: Posttraumatic stress disorder (PTSD) often co-occurs with panic disorder (PD), with some etiological models positing a causal role of panic reactivity in PTSD onset; however, data addressing the temporal ordering of these conditions are lacking. The aim of this study was to examine the bi-directional associations between PD and PTSD in a nationally representative, epidemiologic sample of trauma-exposed adults. METHODS: Participants were community-dwelling adults (62.6% women; Mage = 48.9, SD 16.3) with lifetime DSM-IV PTSD criterion A trauma exposure drawn from the 2001/2 National Epidemiologic Survey on Alcohol and Related Conditions (NESARC) and re-interviewed in 2004/5 (N = 12,467). Cox discrete-time proportional hazards models with time-varying covariates were used to investigate the bi-directional associations between lifetime PD and PTSD, accounting for demographic characteristics, trauma load, and lifetime history of major depression, generalized anxiety disorder, and social anxiety disorder. RESULTS: PD was significantly associated with subsequent onset of PTSD (HR 1.210, 95%CI = 1.207-1.214, p < .001), and PTSD was significantly associated with onset of PD (HR 1.601, 95% CI 1.597-1.604, p < .001). The association between PTSD and subsequent PD was stronger in magnitude than that between PD and subsequent PTSD (Z = - 275.21, p < .01). Men evidenced stronger associations between PD and PTSD compared to women. CONCLUSIONS: Results were consistent with a bidirectional pathway of risk, whereby PD significantly increased risk for the development of PTSD, and PTSD significantly increased risk for PD. Given the association between PTSD and subsequent PD, particularly among men, clinicians may consider supplementing PTSD treatment with panic-specific interventions, such as interoceptive exposure, to prevent or treat this disabling comorbidity.

Shared and specific genetic risk factors for lifetime major depression, depressive symptoms and neuroticism in three population-based twin samples.

BACKGROUND: Vulnerability to depression can be measured in different ways. We here examine how genetic risk factors are inter-related for lifetime major depression (MD), self-report current depressive symptoms and the personality trait Neuroticism. METHOD: We obtained data from three population-based adult twin samples (Virginia n = 4672, Australia #1 n = 3598 and Australia #2 n = 1878) to which we fitted a common factor model where risk for 'broadly defined depression' was indexed by (i) lifetime MD assessed at personal interview, (ii) depressive symptoms, and (iii) neuroticism. We examined the proportion of genetic risk for MD deriving from the common factor v. specific to MD in each sample and then analyzed them jointly. Structural equation modeling was conducted in Mx. RESULTS: The best fit models in all samples included additive genetic and unique environmental effects. The proportion of genetic effects unique to lifetime MD and not shared with the broad depression common factor in the three samples were estimated as 77, 61, and 65%, respectively. A cross-sample mega-analysis model fit well and estimated that 65% of the genetic risk for MD was unique. CONCLUSION: A large proportion of genetic risk factors for lifetime MD was not, in the samples studied, captured by a common factor for broadly defined depression utilizing MD and self-report measures of current depressive symptoms and Neuroticism. The genetic substrate for MD may reflect neurobiological processes underlying the episodic nature of its cognitive, motor and neurovegetative manifestations, which are not well indexed by current depressive symptom and neuroticism.

Childhood Risk Factors for Heavy Episodic Alcohol Use and Alcohol Problems in Late Adolescence: A Marginal Structural Model Analysis.

OBJECTIVE: This study seeks to clarify the nature of the association between five well-studied late childhood predictors and alcohol-related behaviors in adolescence. METHOD: We examined, in 7,168 subjects from the Avon Longitudinal Study of Parents and Children (ALSPAC), using linear probability and marginal structural models, the association between parental alcohol problems, peer group deviance, antisocial behavior, and low parental monitoring, and sensation seeking assessed at multiple times from ages 12.5 to 18 years and heavy episodic drinking and alcohol problems at ages 16.5, 17.5, and 20 years. RESULTS: Based on the pattern of the attenuation in the association with heavy episodic drinking and alcohol problems from the linear probability to marginal structural models, our five factors were divisible into three groups. For parental alcohol problems, no substantial attenuation was seen. For peer group deviance and antisocial behavior, the associations in the marginal structural models were modestly attenuated (10%-20%). By contrast, for low parental monitoring and sensation seeking, moderate attenuations of 41% and 35%, respectively, were observed. CONCLUSIONS: Our results are consistent with the hypothesis that all or nearly all of the association between parental alcohol problems and heavy episodic drinking and alcohol problems in mid to late adolescence is causal. For peer group deviance and antisocial behavior, the large majority of the associations appear to be causal, but confounding influences are also present. However, for low parental monitoring and sensation seeking, our findings suggest that a substantial proportion of the observed association with alcohol outcomes reflects confounding rather than causal influences.

The impact of resilience and subsequent stressful life events on MDD and GAD.

BACKGROUND: There remains a dearth of research examining the "buffering" effect of resilience, wherein resilience at one point in time would be expected to protect an individual against development of psychopathology following future adverse life events. METHODS: Using longitudinal data from an epidemiological twin sample (N = 7463), this study tested whether resilience would act as a buffer for stressful life events (SLEs) against risk for major depressive disorder (MDD) and generalized anxiety disorder (GAD). Resilience, demographics, and psychopathology were measured at Time 1 and recent SLEs and current MDD and GAD were measured at Time 2. RESULTS: Final models, controlling for demographic covariates and Time 1 diagnosis, examined the impact of Time 1 resilience, recent SLEs, their interaction, and a three-way interaction adding sex on MDD and GAD. CONCLUSIONS: The pattern of findings was the same for MDD and GAD, wherein main effects and two-way interactions of resilience and SLEs were significant, such that greater resilience was protective even in the context of high numbers of past-year SLEs. The three-way interaction was not significant, suggesting that the relationship between SLEs and resilience on psychopathology was the same for both men and women. Findings support the conceptualization of resilience as a buffer against the impact of future life stressors on common internalizing psychopathology. Longitudinal designs and trajectory-based studies that include recurring measures of SLEs could inform conceptualizations of resilience in the context of ongoing adversity and aid in developing interventions aimed at fostering healthy adaptation in the face of stressors.

Sex similarities and differences in risk factors for recurrence of major depression.

BACKGROUND: Major depression (MD) occurs about twice as often in women as in men, but it is unclear whether sex differences subsist after disease onset. This study aims to elucidate potential sex differences in rates and risk factors for MD recurrence, in order to improve prediction of course of illness and understanding of its underlying mechanisms. METHODS: We used prospective data from a general population sample (n = 653) that experienced a recent episode of MD. A diverse set of potential risk factors for recurrence of MD was analyzed using Cox models subject to elastic net regularization for males and females separately. Accuracy of the prediction models was tested in same-sex and opposite-sex test data. Additionally, interactions between sex and each of the risk factors were investigated to identify potential sex differences. RESULTS: Recurrence rates and the impact of most risk factors were similar for men and women. For both sexes, prediction models were highly multifactorial including risk factors such as comorbid anxiety, early traumas, and family history. Some subtle sex differences were detected: for men, prediction models included more risk factors concerning characteristics of the depressive episode and family history of MD and generalized anxiety, whereas for women, models included more risk factors concerning early and recent adverse life events and socioeconomic problems. CONCLUSIONS: No prominent sex differences in risk factors for recurrence of MD were found, potentially indicating similar disease maintaining mechanisms for both sexes. Course of MD is a multifactorial phenomenon for both males and females.

Posttraumatic stress disorder and alcohol dependence: Epidemiology and order of onset.

OBJECTIVE: Posttraumatic stress disorder (PTSD) and alcohol dependence (AD) frequently co-occur; however, epidemiologic studies of temporal associations between PTSD and AD are limited. The aims of this study were (a) to investigate the bidirectional associations between PTSD and AD and (b) to examine demographic and clinical correlates of order-of-onset among individuals with PTSD and AD. METHOD: Participants were 11,103 adults (60.6% women; Mage = 48.7 years, SD = 15.9) from the National Epidemiologic Survey on Alcohol and Related Conditions who endorsed lifetime alcohol consumption and DSM-IV PTSD Criterion A trauma exposure (American Psychiatric Association, 2000). Cox proportional hazards models with time-dependent covariates were used to evaluate bidirectional associations between PTSD and AD. Sex differences were assessed using stratified analyses. RESULTS: After adjusting for demographic, trauma, and alcohol characteristics, PTSD was associated with greater likelihood of subsequent AD (hazard ratio [HR] = 1.359, 95% CI = 1.357-1.362), and AD was associated with greater likelihood of subsequent PTSD (HR = 1.274, 95% CI = 1.271-1.277). Bidirectional associations between PTSD and AD were stronger for women compared with men. Among individuals with PTSD and AD, initial onset of PTSD was associated with younger age of first potentially traumatic event. Initial onset of AD was associated with earlier initiation of alcohol use, earlier onset of heavy alcohol use, family history of alcohol problems, and history of generalized anxiety disorder and social anxiety disorder for women but not men. Initial AD was associated with lifetime panic disorder for men and women. CONCLUSIONS: Etiology of PTSD and AD is heterogeneous, and order of onset may reflect differing risk pathways. (PsycINFO Database Record

Clinical features of and risk factors for major depression with history of postpartum episodes in Han Chinese women: A retrospective study.

BACKGROUND: We sought to investigate the clinical features of and risk factors for recurrent major depression (MD) with history of postpartum episodes (PPD) in Han Chinese women and the differences between first-onset postpartum MD (MD that has its first lifetime depressive episode in the postpartum period) and first-onset non-postpartum MD (MD with history of PPD and has its first lifetime depressive episode in a period other than postpartum). METHODS: Data were derived from the China, Oxford and Virginia Commonwealth University Experimental Research on Genetic Epidemiology (CONVERGE) study (N=6017 cases) and analyzed in two steps. We first examined the clinical features of and risk factors for MD patients with (N=981) or without (N=4410) a history of PPD. We then compared the differences between first-onset postpartum MD (N=583) and first-onset non-postpartum MD (N=398) in those with a history of PPD. Linear, logistic and multinomial logistic models were employed to measure the associations. RESULTS: A history of PPD was associated with more guilt feelings, greater psychiatric comorbidity, higher neuroticism, earlier onset and more chronicity (OR 0.2-2.8). Severe premenstrual symptoms (PMS) and more childbirths increased the risk of PPD, as did a family history of MD, childhood sexual abuse, stressful life events and lack of social support (OR 1.1-1.3). In the MD with history of PPD subsample, first-onset postpartum MD was associated with fewer recurrent major depressive episodes, less psychiatric comorbidity, lower neuroticism, less severe PMS and fewer disagreements with their husbands (OR 0.5-0.8), but more childbirths (OR 1.2). LIMITATIONS: Data were obtained retrospectively through interview and recall bias may have affected the results. CONCLUSIONS: MD with history of PPD in Han Chinese women is typically chronic and severe, with particular risk factors including severe PMS and more childbirths. First-onset postpartum MD and first-onset non-postpartum MD can be partly differentiated by their clinical features and risk factors, but are not clearly distinctive.

Sex differences in the pathways to symptoms of alcohol use disorder: a study of opposite-sex twin pairs.

BACKGROUND: We sought to develop an empirical, broad-based developmental model for sex differences in risk for symptoms of alcohol use disorders, here called alcohol problems (APs). METHODS: We assessed 18 risk factors in 5 developmental tiers in both members of 1,377 opposite-sex dizygotic twin pairs from the Virginia population-based twin registry. Analyses were conducted by structural modeling, examining within-pair differences. RESULTS: The best-fitting model explained 73% of the variance in men and 71% in women for last year AP. Forty-nine percent of paths differed significantly across sexes. Ten variables had appreciably different predictive effects on AP in males versus females. Three were stronger in females: familial risk, early-onset anxiety disorders, and nicotine dependence. Seven predictors had a stronger total effect in males: novelty seeking, conduct disorder, childhood sexual abuse, parental loss, neuroticism, low self-esteem, and low marital satisfaction. CONCLUSIONS: In a co-twin control design, which matches sisters and brothers on genetic and familial-environmental background, we found numerous sex differences in predictors of last year AP. Factors that were more prominent in men and in women were diverse, reflecting both internalizing and externalizing psychopathology. The model was slightly more successful at predicting AP in men than in women.

Multiple risk factors predict recurrence of major depressive disorder in women.

BACKGROUND: It is difficult to predict recurrence of depressive episodes in patients with major depression (MD): evidence for many risk factors is inconsistent and general prediction algorithms are lacking. The aim of this study was to develop a prediction model for recurrence of depressive episodes in women using improved methodology. METHODS: We used prospective data from a general population sample of female twins with a last-year MD episode (n=194). A rich set of baseline predictors was analyzed with Cox proportional hazards regression subject to elastic net regularization to find a model predicting recurrence of depressive episodes. Prediction accuracy of the model was assessed in an independent test sample (n=133), which was limited by the unavailability of a number of key predictors. RESULTS: A wide variety of risk factors predicted recurrence of depressive episodes in women: depressive and anxiety symptoms during the index episode, the level of symptoms at the moment of interview, psychiatric and family history, early and recent adverse life events, being unmarried, and problems with friends and finances. Kaplan Meier estimated survival curves showed that the model differentiated between patients at higher and lower risk for recurrence; estimated areas under the curve were in the range of 0.61-0.79. LIMITATIONS: Despite our rich set of predictors, certain potentially relevant variables were not available, such as biological measures, chronic somatic diseases, and treatment status. CONCLUSIONS: Recurrence of episodes of MD in women is highly multifactorial. Future studies should take this into account for the development of clinically useful prediction algorithms.

Genomic influences on alcohol problems in a population-based sample of young adults.

AIMS: Alcohol problems (AP) contribute substantially to the global disease burden. Twin and family studies suggest that AP are genetically influenced, although few studies have identified variants or genes that are robustly associated with risk. This study identifies genetic and genomic influences on AP during young adulthood, which is often when drinking habits are established. DESIGN: We conducted a genome-wide association study of AP. We further conducted gene-based tests, gene ontology analyses and functional genomic enrichment analyses to assess genomic factors beyond single variants that are relevant to AP. SETTING: The Avon Longitudinal Study of Parents and Children, a large population-based study of a UK birth cohort. PARTICIPANTS: Genetic and phenotypical data were available for 4304 participants. MEASUREMENTS: The AP phenotype was a factor score derived from items from the Alcohol Use Disorders Identification Test, symptoms of DSM-IV alcohol dependence, and three additional problem-related items. FINDINGS: One variant met genome-wide significance criteria. Four out of 22,880 genes subjected to gene-based analyses survived a stringent significance threshold (q < 0.05); none of these have been implicated previously in alcohol-related phenotypes. Several biologically plausible gene ontologies were statistically over-represented among implicated single nucleotide polymorphisms (SNPs). SNPs on the Illumina 550 K SNP chip accounted for ~5% of the phenotypical variance in AP. CONCLUSIONS: Genetic and genomic factors appear to play a role in alcohol problems in young adults. Genes involved in nervous system-related processes, such as signal transduction and neurogenesis, potentially contribute to liability to alcohol problems, as do genes expressed in non-brain tissues.

Trauma Exposure and Axis I Psychopathology: A Co-twin Control Analysis in Norwegian Young Adults.

Broad associations between trauma exposure (TE) and Axis I psychopathology have been noted in the literature. However, it is not clear if TE is directly associated with Axis I disorders or if the relationship is better accounted for by familial factors (i.e., early environment and/or genetic factors). The current investigation used the co-twin control method in a large sample of adult twin pairs from the Norwegian Twin Registry (N = 2,776), including 449 twin pairs discordant for DSM-IV Criterion A TE. History of TE and Axis I psychopathology was assessed using DSM-IV based clinical interview. Results suggested that TE was significantly associated with greater likelihood of meeting criteria for major depression, dysthymia, anxiety, substance abuse, eating disorders, and somatization disorder in the general population (odds ratios [OR] ranging from 1.33 to 2.21). Among twins discordant for TE, results suggested that TE may exert a direct influence on major depression, dysthymia, anxiety, substance abuse, eating disorders, and somatization disorder. Shared familial effects may also account for at least some of the relationship between TE and major depression. TE may play an important role in the development of a wide range of Axis I psychopathology above and beyond familial factors. Research and clinical implications are discussed.

The impact of childhood parental loss on risk for mood, anxiety and substance use disorders in a population-based sample of male twins.

Previous studies have identified the relationship between parental loss and psychopathology later in life. However, this relationship varied depending on the kind of loss, the parent involved, and the type of psychopathology. In the present study, we examined the association between parental loss (any loss, death, and separation) during childhood and lifetime risk for seven common psychiatric and substance use disorders in a sample of 2605 male twins from the Virginia population-based twin registry. Using structural equation modeling (SEM), we also examined the extent to which the influence of parental loss contributes to adult psychopathology. Parental separation was associated with a wide range of adult psychopathology, whereas parental death was specifically associated with phobia and alcohol dependence. Maternal and paternal separations were almost equally associated with most forms of psychopathology. SEM suggested that parental loss accounted for about 10% of the variance of adult psychopathology, of which parental separation had the strongest impacts on risk for depression and drug abuse/dependence (11% of the total variance). Our findings suggest that early parental separation has stronger and wider effects on adult psychopathology than parental death.

Socioeconomic status and alcohol-related behaviors in mid- to late adolescence in the Avon Longitudinal Study of Parents and Children.

OBJECTIVE: Prior studies of the relationship between socioeconomic status (SES) and alcohol consumption and problems in adolescence have been inconclusive. Few studies have examined all three major SES indicators and a broad range of alcohol-related outcomes at different ages. METHOD: In the Avon Longitudinal Study of Parents and Children cohort, we examined (by logistic regression, with differential weighting to control for attrition) the relationship between family income and parental education and occupational status, and five alcohol outcomes assessed at ages 16 and 18 years. RESULTS: At age 16, high SES-as indexed by income and education-significantly predicted frequent alcohol consumption. Low SES-as measured by education and occupational status-predicted alcohol-related problems. At age 18, high SES-particularly income and education-significantly predicted frequent alcohol consumption and heavy episodic drinking and, more weakly, symptoms of alcohol dependence. All three measures of SES were inversely related to high-quantity consumption and alcohol behavioral problems. CONCLUSIONS: In adolescents in the United Kingdom, the relationship between SES and alcohol-related behaviors is complex and varies as a function of age, SES measure, and specific outcome. High SES tends to predict increased consumption and, in later adolescence, heavy episodic drinking and perhaps symptoms of alcohol dependence. Low SES predicts alcohol-related behavioral problems and, in later adolescence, high-quantity alcohol consumption.

Sex differences in the pathways to major depression: a study of opposite-sex twin pairs.

OBJECTIVE: The authors sought to clarify the nature of sex differences in the etiologic pathways to major depression. METHOD: Retrospective and prospective assessments of 20 developmentally organized risk factors and the occurrence of past-year major depression were conducted at two waves of personal interviews at least 12 months apart in 1,057 opposite-sex dizygotic twin pairs from a population-based register. Analyses were conducted by structural modeling, examining within-pair differences. RESULTS: Sixty percent of all paths in the best-fit model exhibited sex differences. Eleven of the 20 risk factors differed across sexes in their impact on liability to major depression. Five had a greater impact in women: parental warmth, neuroticism, divorce, social support, and marital satisfaction. Six had a greater impact in men: childhood sexual abuse, conduct disorder, drug abuse, prior history of major depression, and distal and dependent proximal stressful life events. The life event categories responsible for the stronger effect in males were financial, occupational, and legal in nature. CONCLUSIONS: In a co-twin control design, which matches sisters and brothers on genetic and familial-environmental background, personality and failures in interpersonal relationships played a stronger etiologic role in major depression for women than for men. Externalizing psychopathology, prior depression, and specific "instrumental" classes of acute stressors were more important in the etiologic pathway to major depression for men. The results are consistent with previously proposed typologies of major depression that suggest two subtypes that differ in prevalence in women (deficiencies in caring relationships and interpersonal loss) and men (failures to achieve expected goals, with lowered self-worth).

Childhood trauma and personality disorder criterion counts: a co-twin control analysis.

Correlational studies consistently report relationships between childhood trauma (CT) and most personality disorder (PD) criteria and diagnoses. However, it is not clear whether CT is directly related to PDs or whether common familial factors (i.e., shared environment and/or genetic factors) better account for that relationship. The current study used a cotwin control design to examine support for a direct effect of CT on PD criterion counts. Participants were from the Norwegian Twin Registry (N = 2,780), including a subset (n = 898) of twin pairs (449 pairs, 45% monozygotic [MZ]) discordant for CT meeting DSM-IV Posttraumatic Stress Disorder Criterion A. All participants completed the Norwegian version of the Structured Interview for DSM-IV Personality. Significant associations between CT and all PD criterion counts were detected in the general sample; however, the magnitude of observed effects was small, with CT accounting for no more than approximately 1% of variance in PD criterion counts. A significant, yet modest, interactive effect was detected for sex and CT on Schizoid and Schizotypal PD criterion counts, with CT being related to these disorders among women but not men. After common familial factors were accounted for in the discordant twin sample, CT was significantly related to Borderline and Antisocial PD criterion counts, but no other disorders; however, the magnitude of observed effects was quite modest (r2 = .006 for both outcomes), indicating that the small effect observed in the full sample is likely better accounted for by common genetic and/or environmental factors. CT does not appear to be a key factor in PD etiology.

Dimensions of parental alcohol use/problems and offspring temperament, externalizing behaviors, and alcohol use/problems.

BACKGROUND: Alcohol consumption (AC) and alcohol problems (AP) are complex traits. How many factors reflecting parental AC and AP are present in the large prospectively followed Avon Longitudinal Study of Parents and Children cohort? Would these factors be uniquely associated with various temperamental and alcohol-related outcomes in the children? METHODS: We factor-analyzed multiple items reflecting maternal and paternal AC and AP measured over a 12-year period from before the birth of the child (n = 14,093 families). We examined, by linear regression controlling for socioeconomic status, the relationship between scales derived from these factors and offspring early childhood temperament, externalizing traits, and adolescent AC and AP (ns ranging from 9,732 to 3,454). RESULTS: We identified 5 coherent factors: typical maternal AC, maternal AC during pregnancy, maternal AP, paternal AC, and paternal AP. In univariate analyses, maternal and paternal AC and AP were modestly and significantly associated with low shyness, sociability, hyperactivity, and conduct problems in childhood and early adolescence; delinquent behavior at age 15; and AC and AP at ages 15 and 18. AC and AP at age 18 were more strongly predicted by parental factors than at age 15. Maternal AC during pregnancy uniquely predicted externalizing traits at ages 4, 13, and 15. CONCLUSIONS: Parental AC and AP are complex multidimensional traits that differ in their association with a range of relevant measures in their children. Controlling for background AC and AP, self-reported levels of maternal AC during pregnancy uniquely predicted externalizing behaviors in childhood and adolescence.

Parenting and risk for mood, anxiety and substance use disorders: a study in population-based male twins.

BACKGROUND: Previous studies consistently identified a relationship between parenting behavior and psychopathology. In this study, we extended prior analyses performed in female twins to a large sample of twins from male-male pairs. METHODS: We used interview data on 2,609 adult male twins from a population-based twin registry. We examined the association between three retrospectively reported parenting dimensions (coldness, protectiveness, and authoritarianism) and lifetime history of seven common psychiatric and substance use disorders. Using univariate structural equation modeling, we also examined the influence of the genetic and environmental factors on parenting. RESULTS: Examined individually, coldness was consistently associated with risk for a broad range of adult psychopathology. Averaged odds of psychiatric disorders associated with parenting were increased between 26 and 36 %. When the three parenting dimensions were examined together, coldness remained significant for major depression, phobia, and generalized anxiety disorder. Controlling for other disorders, the associations between the parenting dimensions and psychopathology were non-specific. Twin fitting model demonstrated that modest heritability accounted for parenting, whereas most variance resulted from the non-shared environment. CONCLUSIONS: Based on our current and prior findings, there is broad similarity in the impact of parenting on adult psychopathology between men and women.

Two-part random effects growth modeling to identify risks associated with alcohol and cannabis initiation, initial average use and changes in drug consumption in a sample of adult, male twins.

AIMS: Our aim was to profile alcohol and cannabis initiation and to characterize the effects of developmental and environmental risk factors on changes in average drug use over time. DESIGN: We fitted a two-part random effects growth model to identify developmental and environmental risks associated with alcohol and cannabis initiation, initial average use and changes in average use. PARTICIPANTS: 1796 males aged 24-63 from the Virginia Adult Twin Study of Psychiatric and Substance Use Disorders. MEASUREMENTS: Data from three interview waves included self-report measures of average alcohol and cannabis use between ages 15 and 24, genetic risk of problem drug use, childhood environmental risks, personality, psychiatric symptoms, as well as personal, family and social risk factors. FINDINGS: Average alcohol and cannabis use were correlated at all ages. Genetic risk of drug use based on family history, higher sensation seeking, and peer group deviance predicted both alcohol and cannabis initiation. Higher drug availability predicted cannabis initiation while less parental monitoring and drug availability were the best predictors of how much cannabis individuals consumed over time. CONCLUSION: The liability to initiate alcohol and cannabis, average drug use as well as changes in drug use during teenage years and young adulthood is associated with known risk factors.

The impact of environmental experiences on symptoms of anxiety and depression across the life span.

Symptoms of anxiety and depression are relatively stable over time. Can this stability be explained by genetic influences, or is it caused by the long-lasting effects of accumulating environmental experiences? To address this question, we analyzed longitudinally assessed symptoms of anxiety and depression in eight samples of monozygotic twins of widely varying ages. These samples were drawn from American and European population-based registries. Using hierarchical linear modeling, we examined individual differences and individual changes in the level of symptoms over time. This method enabled us to decompose the variance into the predictable variance shared by both members of each pair of twins, the differences between individuals within pairs, and the residual variance. We then modeled how these components of individual variation changed over time. Within pairs, the twins' predicted levels of symptoms increasingly diverged from childhood until late adulthood, at which point the divergence ceased. By middle adulthood, environmental experiences contributed substantially to stable and predictable interindividual differences in levels of anxiety and depression.