Clinical and Behavioural Characteristics of Youth Accessing Residential Substance Use Treatment in Australia

Objective: Youth accessing residential substance use disorder (SUD) treatment often present with complexities that may impact treatment responsivity, signalling the need for additional interventions. Methods: This study characterised clinical and behavioural characteristics in 100 youth (57 female) aged 18-25 accessing residential SUD treatment in Victoria, Australia. Results: All participants met criteria for at least one SUD (M = 2.2, SD =2.1), with 66% meeting criteria for two or more concurrent SUDs (i.e., polysubstance use). Nearly half (48%) met the threshold for likely general personality disorder (PD), measured by impairments in levels of personality functioning, and 43% met the threshold for likely antisocial personality disorder (ASPD) via ASPD-specific personality functioning. Compared to those without likely general PD, participants with likely general PD endorsed more polysubstance use. Conversely, ASPD-specific personality functioning was linked to higher rates of methamphetamine, alcohol, and sedative use disorders, and polysubstance use. Elevated early maladaptive schemas (e.g., 53% endorsing insufficient self-control) and antisocial attitudes were endorsed across the sample. Over half (59%) reported a prior arrest, with 23% reporting ten or more arrests. Findings highlight the relationship between personality functioning and SUD, as well as the high prevalence of psychological and behavioural complexities endorsed by youth accessing residential SUD treatment. Conclusions: Implications include the need for routine personality screening, potential benefit of schema-focused treatment, and interventions targeting antisocial cognition and behaviour alongside SUD treatment for this population. Embedding such interventions may improve engagement, reduce relapse and offending, and provide a developmentally informed pathway to improve outcomes.