Psychological Distress Trajectories in Residential Alcohol and Other Drug Treatment

Residential clients frequently report high psychological distress at intake, but little is known about changes in distress throughout treatment. This study aimed to identify in-treatment trajectories for psychological distress and factors associated with trajectory classes.

A retrospective cohort of adults attending Australian non-government residential substance use treatment between 2012 and 2023 was identified from routinely collected data, NADAbase. Participants (N = 1492) completed ≥ 3 Kessler-10 Psychological Distress Scale (K10) assessments within 90 days of intake. Latent growth curve analyses identified classes of K10 trajectories. Multinomial regression identified demographic and clinical correlates (Severity of Dependence Scale [SDS] and EUROHIS Quality of Life scale [EQoL-8]) of class membership.

A five-class model describing K10 trajectories (1: moderate-low improved; 2: high-low improved; 3: very high-moderate improved; 4: very high-high improved; 5: very high unchanged) had the best model fit. Compared to high-low improved (34.5%; referent), moderate-low improved (45.4%) were less likely to identify as female, have higher SDS and lower EQoL-8 scores, or use cannabis; very high-moderate improved (13.1%) were more likely to have lower SDS scores, be aged under 25 and use opioids; very high-high improved (5.6%) were less likely to identify as male, be aged over 25, have higher EQoL and SDS scores; and very high unchanged (1.3%) were more likely to have lower EQoL scores and have left without completing treatment.

Four K10 trajectory classes showed improvement after 90 days. Around 7% reported sustained high to very high psychological distress. Routine monitoring of psychological distress provides opportunities to identify non-improving clients and review treatment plans to improve outcomes.