Associations between adolescent cannabis use and young-adult functioning in three longitudinal twin studies.

Observational studies have linked cannabis use to an array of negative outcomes, including psychiatric symptoms, cognitive impairment, and educational and occupational underachievement. These associations are particularly strong when cannabis use occurs in adolescence. Nevertheless, causality remains unclear. The purpose of the present study was thus to examine associations between prospectively assessed adolescent cannabis use and young-adult outcomes (psychiatric, cognitive, and socioeconomic) in three longitudinal studies of twins (n = 3,762). Twins reporting greater cumulative cannabis use in adolescence reported higher levels of psychopathology as well as poorer socioeconomic outcomes in young adulthood. However, cannabis use remained associated only with socioeconomic outcomes (i.e., educational attainment, occupational status, and income) in monozygotic-cotwin control analyses, which account fully for shared genetic and environmental confounding. Follow-up analyses examining associations between twin differences in adolescent cannabis use and longitudinal change in academic functioning during the middle- and high-school years provided a possible mechanism for these associations, indicating that greater cannabis use during this period was associated with decreases in grade point average and academic motivation as well as increases in academic problem behavior and school disciplinary problems. Our findings thus suggest that cannabis use in adolescence has potentially causal, deleterious effects on adolescent academic functioning and young-adult socioeconomic outcomes despite little evidence suggesting a strong, causal influence on adult mental health or cognitive ability.

Age-Moderation of Genetic and Environmental Contributions to Cognitive Functioning in Mid- and Late-Life for Specific Cognitive Abilities.

Age moderation of genetic and environmental contributions to Digits Forward, Digits Backward, Block Design, Symbol Digit, Vocabulary, and Synonyms was investigated in a sample of 14,534 twins aged 26 to 98 years. The Interplay of Genes and Environment across Multiple Studies (IGEMS) consortium contributed the sample, which represents nine studies from three countries (USA, Denmark, and Sweden). Average test performance was lower in successively older age groups for all tests. Significant age moderation of additive genetic, shared environmental, and non-shared environmental variance components was observed, but the pattern varied by test. The genetic contribution to phenotypic variance across age was smaller for both Digit Span tests, greater for Synonyms, and stable for Block Design and Symbol Digit. The non-shared environmental contribution was greater with age for the Digit Span tests and Block Design, while the shared environmental component was small for all tests, often more so with age. Vocabulary showed similar age-moderation patterns as Synonyms, but these effects were nonsignificant. Findings are discussed in the context of theories of cognitive aging.

Biometric Modeling of Gene-Environment Interplay: The Intersection of Theory and Method and Applications for Social Inequality.

For more than a decade, biometric moderation models have been used to examine whether genetic and environmental influences on individual differences might vary within the population. These quantitative Gene × Environment interaction models have the potential to elucidate not only when genetic and environmental influences on a phenotype might differ, but also why, as they provide an empirical test of several theoretical paradigms that serve as useful heuristics to explain etiology-diathesis-stress, bioecological, differential susceptibility, and social control. In the current article, we review how these developmental theories align with different patterns of findings from statistical models of gene-environment interplay. We then describe the extant empirical evidence, using work by our own research group and others, to lay out genetically informative plausible accounts of how phenotypes related to social inequality-physical health and cognition-might relate to these theoretical models.

Does education lower allostatic load? A co-twin control study.

Many studies have found that education is associated with better health, but the causal basis of this association is unclear. The current study used a co-twin control design to examine if differences in years of education within twin pairs predict allostatic load. The strength of this design is that it controls for genetic and other familial confounds shared between twins. The sample consisted of 381 twins (with 292 twins from 146 complete pairs; mean age=57; 61% female) who participated in the biomarker project of the Midlife Development in the United States (MIDUS) study. Individual-level analyses showed a significant, negative association between years of education and allostatic load, but this association was explained entirely by familial influences shared between twins. The results of this study suggest that schooling does not itself protect against allostatic load.

G×E Interaction Influences Trajectories of Hand Grip Strength.

Age-related decline in grip strength predicts later life disability, frailty, lower well-being and cognitive change. While grip strength is heritable, genetic influence on change in grip strength has been relatively ignored, with non-shared environmental influence identified as the primary contributor in a single longitudinal study. The extent to which gene-environment interplay, particularly gene-environment interactions, contributes to grip trajectories has yet to be examined. We considered longitudinal grip strength measurements in seven twin studies of aging in the Interplay of Genes and Environment across Multiple Studies consortium. Growth curve parameters were estimated for same-sex pairs, aged 34-99 (N = 10,681). Fisher's test for mixture distribution of within-monozygotic twin-pair differences (N = 1724) was performed on growth curve parameters. We observed significant gene-environment interaction on grip strength trajectories. Finally, we compared the variability of within-pair differences of growth curve parameters by APOE haplotypes. Though not statistically significant, the results suggested that APOE ɛ2ɛ2/ɛ2ɛ3 haplotypes might buffer environmental influences on grip strength trajectories.

Socioeconomic status moderates genetic and environmental effects on the amount of alcohol use.

BACKGROUND: Much is unknown about the relationship between socioeconomic status (SES) and alcohol use, including the means by which SES may influence risk for alcohol use. METHODS: Using a sample of 672 twin pairs (aged 25 to 74) derived from the MacArthur Foundation Survey of Midlife Development in the United States, this study examined whether SES, measured by household income and educational attainment, moderates genetic and environmental influences on 3 indices of alcohol use: amount used, frequency of use, and problem use. RESULTS: We found significant moderation for amount of alcohol used. Specifically, genetic effects were greater in low-SES conditions, shared environmental effects (i.e., environmental effects that enhance the similarity of twins from the same families) tended to increase in high-SES conditions, and nonshared environmental effects (i.e., environmental effects that distinguish twins) tended to decrease with SES. This pattern of results was found for both income and education, and it largely replicated at a second wave of assessment spaced 9 years after the first. There was virtually no evidence of moderation for either frequency of alcohol use or alcohol problems. CONCLUSIONS: Our findings indicate that genetic and environmental influences on drinking amount vary as a function of the broader SES context, whereas the etiologies of other drinking phenomena are less affected by this context. Efforts to find the causes underlying the amount of alcohol used are likely to be more successful if such contextual information is taken into account.

Evidence-based practice in psychology: Context, guidelines, and action.

A science-based approach to understanding health and disease emerged gradually over the past two centuries, while the modern evidence-based approach to health care emerged only about a half-century ago. The evidence-based approach to practice in health service psychology (HSP) gained significant traction after the American Psychological Association (APA) adopted it as policy in 2005, and in 2021, APA approved the first comprehensive set of guidelines for practicing HSP in an evidence-based manner. Several authors of this 2021 set of guidelines along with an additional subject matter expert wrote the current article. This article outlines the development of evidence-based practice in psychology, discusses the strengths and weaknesses of each of the three components of evidence-based practice (i.e., best available research, clinical expertise, and patient characteristics, culture, and preferences), and highlights the complexity involved in integrating related considerations during clinical decision making. The article then discusses strategies for the systematic application of this approach in HSP to improve the effectiveness of behavioral health care and strengthen population health. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Adaptation of the patient feedback survey at a community treatment setting.

The Patient Feedback Survey is a performance improvement measure designed to assess the quality of outpatient substance abuse treatment. We modified and administered this measure to 500 individuals at a multisite treatment provider. Although the feedback scores were high in general, analyses of variance showed score variability in relation to type and length of treatment. Moreover, respondents who reported any use of marijuana, cravings for substances, or mutual-support group attendance (ie, Alcoholics Anonymous or Narcotics Anonymous) had lower feedback scores than respondents without these experiences. We highlight the importance of investigating treatment evaluations in the context of other recovery experiences.

The relationships of perpetrator and victim substance use to the sexual aggression of rapists and child molesters.

OBJECTIVE: This study investigated substance use in rape and child molestation. We hypothesized that perpetrator substance use would be associated with a greater increase in rapists' aggression in sexual crimes compared with that of child molesters. We also predicted that victim substance use would be negatively related to both rapists and child molesters' aggression in sexual crimes. METHOD: The sample included 245 male rapists and 273 male child molesters who had been evaluated at the Massachusetts Treatment Center (MTC) between 1959 and 1991 for potential civil commitment. Data were obtained from offenders' archival records and were coded by trained research assistants on perpetrator and victim substance use and perpetrator aggression in sexual crimes. RESULTS: Analyses showed that the magnitude of the positive association between perpetrator alcohol use and aggression in sexual crimes did not differ between rapists and child molesters. In contrast, perpetrator drug use was associated with increased aggression among child molesters only. Victim substance use was related to increased aggression among rapists only. CONCLUSIONS: The results indicate that victim substance use and perpetrator drug use, but not perpetrator alcohol use, are differentially related to the aggression of rapists and child molesters in sexual crimes. Those findings imply that substance use may play different roles depending on offender type.

Implementing an adapted version of the job seekers' workshop in a residential program for patients with substance use disorders.

OBJECTIVES: To evaluate the feasibility and effectiveness of adapting the Job Seekers' Workshop (JSW) to a residential setting within a Massachusetts-based substance use disorder treatment agency. METHODS: Implementation of the adapted JSW consisted of a continual sequence of three weekly sessions that focused on job interview rehearsals, practice completing job applications, and identification of job leads. Data were compiled on the employment rates of the 188 patients discharged from the residential treatment program during July - December 2006 (baseline participants, n = 95) and January - June 2007 (JSW intervention participants, n = 93). The effectiveness of the adapted JSW was evaluated through a comparison of baseline and intervention participants' employment rates at discharge from residential treatment. RESULTS: Analyses indicated a trend towards a significant increase in employment at discharge for the intervention period (40.9%) compared to baseline (29.5%), χ(2)(1, N = 188) = 2.675, p = .051. CONCLUSIONS: Further evaluation of the JSW in residential settings is necessary, but this preliminary research suggests that the intervention could begin to address the need for vocational services in residential treatment for substance use disorders.