The number of episodes of major psychiatric and substance use disorders as an index of genetic risk and genetic heterogeneity.

We investigate whether number of episodes (NoEs) meaningfully reflect genetic risk and genetic heterogeneity for five primary disorders-Drug Use Disorder (DUD), Alcohol Use Disorder (AUD), Major Depression (MD), Bipolar Disorder (BD), and Schizophrenia (SZ) ascertained from Swedish population registries. We utilize Genetic Risk Ratios (GRR)-defined as the ratio of the genetic risk for secondary disorders to the genetic risk for the primary disorder-derived from Family Genetic Risk Scores (FGRS). For all five primary disorders, genetic risk rose robustly with increasing NoEs.

Peer Social Genetic Effects and the Etiology of Substance Use Disorders, Major Depression, and Anxiety Disorder in a Swedish National Sample.

Objective: There is growing interest in how peers' genotypes may influence health (i.e., peer social genetic effects).

Association between adolescent alcohol use and cognitive function in young adulthood: A co-twin comparison study.

Background And Aims: Studies on adolescent alcohol use and cognition are often unable to separate the potential causal effects of alcohol use on cognition from shared etiological influences, including genetic influences or other substance use comorbidities also known to be associated with cognition, such as nicotine use. The present study aimed to fill this gap and clarify the relationship between adolescent alcohol use and young adult cognition by accounting for both measured and unmeasured confounders.

Design: A random effects model accounting for nesting in families was used to control for measured confounders.

Comorbidity and sex differences in functional disorders and internalizing disorders.

Objective: In the current exploratory study we estimate comorbidity rates between FDs [fibromyalgia (FM), myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS), and irritable bowel syndrome (IBS)]-and IDs-[major depressive disorder (MDD) and generalized anxiety disorder (GAD)] by using self-reported diagnostic criteria.

Method: We analyzed data from 107,849 participants (mean age = 49.3 (SD = 13.

A Bivariate Twin Study of Lifetime cannabis Initiation and Lifetime Regular Tobacco Smoking Across Three Different Countries.

Regular cigarette smoking and cannabis consumption are strongly positively related to each other, yet few studies explore their underlying variation and covariation. We evaluated the genetic and environmental decomposition of variance and covariance of these two traits in twin data from three countries with different social norms and legislation. Data from the Netherlands Twin Register, FinnTwin12/16, and the Minnesota Center for Twin Family Research (total N = 21,617) were analyzed in bivariate threshold models of lifetime regular smoking initiation (RSI) and lifetime cannabis initiation (CI).

The Prediction of Diagnostic Change From Bipolar Disorder to Schizophrenia and Schizophrenia to Bipolar Disorder in a Population-Based, Longitudinal, National Swedish Sample.

Background And Hypothesis: To clarify, in a large, representative, longitudinal sample, the rate and predictors of diagnostic conversion from Bipolar Disorder (BD) to Schizophrenia (SZ) and from SZ→BD.

Design: From individuals born in Sweden 1950-1995 and living there in 1970 or later, we identified at least one initial diagnoses of SZ (n = 8449) and BD (n = 8438) followed for a minimum of 10 and a mean of 24 years. Diagnostic conversion required, respectively, at least two final diagnoses of BD and SZ 30 days apart with no intervening diagnosis of SZ or BD.

Unidirectional and Bidirectional Causation between Smoking and Blood DNA Methylation: Evidence from Twin-based Mendelian Randomisation.

Cigarette smoking is associated with numerous differentially-methylated genomic loci in multiple human tissues. These associations are often assumed to reflect the causal effects of smoking on DNA methylation (DNAm), which may underpin some of the adverse health sequelae of smoking. However, prior causal analyses with Mendelian Randomisation (MR) have found limited support for such effects.

The impact of family-genetic risk scores on social functioning in individuals affected with six major psychiatric and substance use disorders in a Swedish National Sample.

To examine whether the level of genetic risk in psychiatric disorders impacts the social functioning of affected individuals, we examine the relationship between genetic risk factors for major depression (MD), anxiety disorders (AD), bipolar disorder (BD), non-affective psychosis (NAP), alcohol use disorder (AUD), and drug use disorder (DUD) in disordered individuals and five adverse social outcomes: unemployment, residence in areas of social deprivation, social welfare, early retirement, and divorce. We examine all cases with registration for these disorders from 1995 to 2015 in individuals born in Sweden. Genetic risk was assessed by the family genetic risk score (FGRS) and statistical estimates by Cox proportional hazard models.

Temporal relations between alcohol use, posttraumatic stress disorder, and internalizing symptoms during the COVID-19 pandemic: An ecological momentary assessment investigation.

Objective: COVID-19 is a collective stressor associated with both increased mental health symptoms and increased frequency of alcohol use. These increases highlight the need for investigations into the functional relationships between traumatic stress symptoms and alcohol use in the wake of the pandemic. This study sought to use ecological momentary assessment to examine the temporal association of posttraumatic stress disorder (PTSD) with alcohol use during the COVID-19 pandemic.

Extended Swedish Adoption Study of Adverse Stress Responses and Posttraumatic Stress Disorder.

Importance: Twin studies have found that posttraumatic stress disorder (PTSD) is influenced by both genetic and environmental factors within a generation. No study has used an adoption design, which can address questions about the degree and sources of cross-generational transmission of adverse stress responses (ASRs) and PTSD.

Objectives: To examine whether ASRs or PTSD are transmitted from parents to offspring, and to clarify the relative importance of genes and rearing.

Testing Quantitative and Qualitative Sex Effects in a National Swedish Twin-Sibling Study of Posttraumatic Stress Disorder.

Objective: Twin studies have demonstrated that posttraumatic stress disorder (PTSD) is moderately heritable, and the pattern of findings across studies suggests higher heritability in females compared with males. Formal testing of sex differences has yet to be done in twin studies of PTSD. The authors sought to estimate the genetic and environmental contributions to PTSD, and to formally test for sex differences, in the largest sample to date of both sexes, among twins and siblings.

Joint hypermobility in functional neurological disorder: A cross-sectional study.

Background: Functional Neurological Disorder (FND) is associated with anxiety and depression, and perhaps with joint hypermobility, which is itself associated with anxiety and depression. We conducted a survey to explore the relationship between these.

Methods: An online survey of people with FND was conducted, with participants asked to nominate healthy controls from their social group to join.

Researching COVID to enhance recovery (RECOVER) pediatric study protocol: Rationale, objectives and design.

Importance: The prevalence, pathophysiology, and long-term outcomes of COVID-19 (post-acute sequelae of SARS-CoV-2 [PASC] or "Long COVID") in children and young adults remain unknown. Studies must address the urgent need to define PASC, its mechanisms, and potential treatment targets in children and young adults.

Observations: We describe the protocol for the Pediatric Observational Cohort Study of the NIH's REsearching COVID to Enhance Recovery (RECOVER) Initiative.

Cohort Effects on Tobacco Consumption and Its Genetic and Environmental Variance Among Finnish Adults Born Between 1880 and 1957.

Introduction: Population research indicates that smoking behaviors in Finland have varied over time by sex and birth cohort. Smoking behaviors are influenced by genes and the environment; like the behaviors themselves, these underlying influences are not necessarily stable over time and may be modifiable by national drug policy.

Aims And Methods: We utilized longitudinal mixed-effects models and causal-common-contingent twin models to evaluate sex and cohort effects on tobacco consumption and the underlying genetic and environmental variance components in a birth cohort sample of same-sex twins born in Finland between 1880 and 1957, assessed in 1975, 1981, 1990, and 2011.

Personality correlates of past-year alcohol use in individuals with severe alcohol use disorder and a lifetime history of involvement in alcoholics anonymous.

Background: Alcohol use disorder (AUD) is a highly impairing condition with important public health impacts. Despite the availability of treatment options for AUD, research shows that few people receive treatment, and even fewer can maintain abstinence/low-drinking levels. This study investigated the role of personality traits in past-year alcohol use among individuals with severe AUD who ever attended Alcoholics Anonymous (AA), a widespread and easily accessible self-help group for alcohol problems.

Socioeconomic position indicators and risk of alcohol-related medical conditions: A national cohort study from Sweden.

Background: Alcohol consumption contributes to excess morbidity and mortality in part through the development of alcohol-related medical conditions (AMCs, including alcoholic cardiomyopathy, hepatitis, cirrhosis, etc.). The current study aimed to clarify the extent to which risk for these outcomes differs as a function of socioeconomic position (SEP), as discrepancies could lead to exacerbated health disparities.