High‑Resolution Clinical Profiling of Age and Sex Differences in Substance Use Severity, Comorbidity, and Impulsivity...

Substance use disorders (SUDs) remain undertreated, particularly when they co-occur with other psychiatric disorders, a clinical presentation that is more common among young adults and females. Responsive service planning requires contemporary clinical benchmarks on how SUD severity, comorbidity, and impulsivity differ by age and sex in real-world treatment settings. This study uses high-resolution clinical assessment data to profile these domains.

Participants were 1,764 individuals from three SUD treatment programs at St. Joseph's Hospital Hamilton and 1,253 individuals from Homewood Health Centre. Regressions examined age (17-25 vs. 26+ years), sex (female vs. male), and age × sex effects on substance use, psychiatric symptoms, and impulsivity at intake. Shoelace plots and comorbidity-to-diagnosis inflation ratios were used for descriptive profiling.

Psychiatric comorbidity was common (61-81%), especially among those with cannabis or illicit drug use disorders. Young adults reported higher cannabis and other drug use and psychiatric symptoms, greater comorbidity, and elevated impulsivity, but lower motivation to change. Females reported higher anxiety, depression, and PTSD symptoms, greater comorbidity, and higher negative urgency. No age × sex interactions emerged.

These findings illustrate systematic differences in psychiatric comorbidity and impulsivity based on age and sex among patients in SUD treatment, providing conceptual benchmarks for these presentations in clinical practice. This highlights the need for integrated tailored assessment and treatment pathways, and particular potential for targeting higher comorbidity, lower motivation, and elevated impulsivity in younger patients.