Researchers from New York University and the University of Pittsburgh have found that in a large, community-based sample, long-term simultaneous use of alcohol, cigarettes, and marijuana was associated with psychiatric disorders in adulthood, including Antisocial Personality Disorder (ASPD), Major Depressive Episode (MDE), and Generalized Anxiety Disorder (GAD). The findings were published in the Journal of Developmental & Behavioral Pediatrics.
There have been numerous studies previously conducted on substance use and psychopathology, but researchers identified a gap in the research.
- Although it is common for individuals to use multiple substances at the same time (eg, to be both a drinker and a smoker, rather than just one or the other), there is limited research on patterns between comorbid substance use and psychopathology.
- Most studies have examined people who are already in treatment for substance use disorders (SUDs), and have shown that individual use of alcohol, cigarettes, or marijuana is associated with psychopathology. However, they did not take into account the large number of adults who engage in long term substance use that doesn’t meet the threshold of a substance use “disorder.”
- Most studies that examine associations between substance use and psychopathology have used cross-sectional designs, or have measured substance use during adolescence or young adulthood.
“A better understanding of distinct patterns of comorbid substance use may be more practically relevant to prevention and treatment programming than focusing on the use of an individual substance [such as] marijuana,” wrote Judith S. Brook, EdD, from the New York University School of Medicine and colleagues.
The authors also noted that researching this area may show that there is value in addressing comorbid substance use in community populations or in clinical populations who haven’t yet been identified as having SUDs, and of examining how lasting substance use may affect individuals during adulthood.
To address these gaps in the research to date, the researchers recruited a random, community-based sample (n = 973 at baseline) with a mean age of 36.6 ± 2.8 years from the Children and Adults in the Community Study, an ongoing study of substance use and psychiatric disorders.
The researchers hypothesized that those who used substances more frequently than “not at all” or “occasional alcohol use” would be associated with ASPD, MDE, and GAD in adulthood; that those who used substances more heavily would be more associated with ASPD, MDE, and GAD; and that those who used marijuana would be more associated with ASPD, MDE, and GAD than those who used alcohol and/or cigarettes only.
The researchers found 5 categories of substance users and their trajectories:
- HHH: Chronic cigarette, alcohol, and marijuana use
- DDD: Delayed/late-starting cigarette, alcohol, and marijuana use
- LML: Low or no cigarette use, moderate alcohol use, and occasional marijuana use
- HMN: Chronic cigarette use, moderate alcohol use, no marijuana use
- NON: Occasional alcohol use only
They found that compared with the NON group, the HHH group had significantly greater risk of having ASPD (Adjusted Odds Ratio [AOR] = 28.52, 95% Confidence Interval [CI] = 9.44-86.17), MDE
(AOR = 2.67, 95% CI = 1.14–6.26), and GAD (AOR = 6.39, 95% CI = 2.62–15.56). However, participants in the DDD, LML, and HMN groups had weaker, less consistent associations with ASPD, MDE, and GAD. The authors also noted that the groups that included marijuana use over time, HHH and LML, were more strongly associated with ASPD than the DDD and HMN groups.
“The fact that membership in the HHH group (chronic smoking, drinking, and marijuana use) was associated with such strong odds for the development of psychopathology suggests that it would be valuable to target these individuals in prevention and treatment programming.
This is notable especially because these were individuals recruited in the community who had not necessarily been identified previously as having SUDs,” the authors wrote. “Especially considering budgetary concerns facing many community-based prevention organizations, it is valuable to know that focusing on this particular group may represent an optimization of resources.”
The researchers also noted that those in the delayed/late-starting group (DDD) had a much lower risk of developing psychopathology compared with the chronic use group (HHH). “This highlights the importance of taking into account trajectories over time instead of simple point estimates of substance use… It would be valuable for future research to address more deeply what it is about delaying substance use that may provide a protective benefit with regard to psychopathology in adulthood.”
The researchers also recommended assessing opioids in this way in future studies.
Summary & Clinical Significance
Researchers have found that in a large, community-based sample, long-term simultaneous use of alcohol, cigarettes, and marijuana was associated with psychiatric disorders in adulthood, such as Antisocial Personality Disorder (ASPD), Major Depressive Episode (MDE), and Generalized Anxiety Disorder (GAD).
“Findings suggest that individuals presenting with substance use should be screened for the use of other substances, and assessed for psychiatric disorders in adulthood,” the authors wrote. “Additionally, results suggest that clinicians [should] diagnose and adapt treatment to the full scope of problems which may affect adults presenting with either substance use, ASPD, MDE, or GAD.
Limitations & Disclosures
- The research sample consisted primarily of white participants from upstate New York, and cannot be generalized to other racial groups, ethnic groups, or other geographic locations.
- Social and environmental factors that may help explain associations between substance use and psychiatric disorders were not examined.
- It is possible that psychopathology or early precursors to adult psychopathology such as childhood conduct disorder may precede long-term substance use.
This research was supported by grant #DA032603 from the National Cancer Institute and by grant #DA000244 from the National Institute on Drug Abuse. Both were awarded to Dr Judith S. Brook.
The authors declare no conflicts of interest.
Xie F, Peltier M, Getahum D. Is the Risk of Autism in Younger Siblings of Affected Children Moderated by Sex, Race/Ethnicity, or Gestational Age? J Dev Behav Pediatr. 2016; doi: 10.1097/DBP.0000000000000341. [Epub ahead of print]