Patterns of Polysubstance Use Among Those with Tranquilizer or Sedative Misuse: Predictors and Functional Consequences

The misuse of tranquilizer and sedative medications (i.e., use without a prescription or at higher doses/longer periods of time than prescribed) is associated with myriad negative sequalae, such as suicidal behaviors and increased risk of overdose. Yet, prescription tranquilizer and sedative misuse has been largely overlooked by the scientific community, clinicians, and policymakers. We addressed this gap in the literature by characterizing subgroups of individuals with tranquilizer or sedative misuse, based on their patterns of polysubstance use. The present study analyzed data from two samples of individuals with past-month tranquilizer or sedative misuse: respondents of a nationally-representative household survey (general population sample; N=970) and individuals in substance use disorder treatment (clinical sample; N=451). Using latent class analysis, we identified two patterns of polysubstance use in the general population sample: (1) sedative misuse with low polysubstance use (approximately 16.6% of the sample), and (2) tranquilizer misuse with high polysubstance use (83.4%). Correlates of expected membership in the tranquilizer misuse with high polysubstance use class included younger age, more motives for misuse, and use without a prescription. We also identified two latent classes in the clinical sample: opioid use with high polysubstance use (approximately 73.1% of the sample) and binge alcohol use with moderate polysubstance use (26.9%). Younger age and lower levels of anxiety sensitivity were associated with expected membership in the opioid use with high polysubstance use class. These results indicate that a majority of tranquilizer/sedative misuse does not occur in isolation, but, rather, is part of a pattern of polysubstance use. This finding is concerning, given the increased risk of overdose when tranquilizers and sedatives are combined with other substances.