Reduced Environmental Stimulation Therapy (REST) in methamphetamine use disorder: a pilot study

Existing treatments for methamphetamine use disorder (MUD) are suboptimal in addressing withdrawal and preventing relapse. Models of addiction have proposed that negative affect plays an influential role in drug craving and relapse. Although Reduced Environmental Stimulation Therapy (REST) has been associated with attenuated negative affect in other psychiatric conditions, it has not been examined as an intervention for MUD. To address this gap, the present study investigated the feasibility, tolerability, and safety of a single session of REST via floatation pool (pool-REST) in treatment-enrolled individuals with MUD. In a within-subject crossover design, participants (<i>n</i> = 78) consented to complete one session each of pool-REST and chair-REST, an active comparator controlling for the effects of simple relaxation and expectation. Feasibility was assessed via completion rate, tolerability via duration of REST utilization, and safety via adverse event incidence. Secondary outcomes were assessed via measurement of self-reported affect, interoceptive sensation, and degree of stimulant craving. 74 % of all recruited participants (<i>n</i> = 58) completed both REST sessions, which were well-tolerated. There were no serious adverse events and participants provided more frequent endorsements of positive versus negative experiences. Although both REST conditions showed significant decreases in ratings of stress/anxiety, negative affect, and stimulant craving, pool-REST was associated with greater increases in positive affect, cardiorespiratory interoceptive awareness, heart rate, and systolic blood pressure than chair-REST. These results demonstrate that REST sessions are feasible, well-tolerated, and safe in individuals with MUD. Randomized control trials are warranted to explore potential salutary effects of pool-REST on MUD remission and recovery.