Proof-of-concept trial of Goal Management Training⁺ to improve executive functions and treatment outcomes in methamphetamine use disorder

Background: Deficits in executive function are common in methamphetamine use disorder (MUD), likely contributing to difficulties in sustained treatment success. Cognitive remediation interventions are designed to treat such deficits but have not been adapted to the needs of people with MUD. This study presents a proof-of-concept trial to evaluate a new cognitive remediation program for MUD, Goal Management Training⁺ (GMT⁺). Methods: This was a cluster-randomised crossover trial comparing GMT⁺ with a psychoeducation-based control (Brain Health Workshop; BHW). GMT⁺ is a therapist-administered group-based cognitive remediation for executive dysfunction comprising four 90-minute weekly sessions and daily journal activities. BHW is a lifestyle psychoeducation program matched to GMT⁺ for therapist involvement, format, and duration. Participants (n = 36; GMT n = 17; BHW n = 19) were recruited from therapeutic communities in Victoria, Australia. Primary outcomes included intervention acceptability, feasibility, and improvements in self-reported executive function. Secondary outcomes included cognitive tests of executive function, severity of methamphetamine dependence, craving, and quality of life. We performed mixed linear modelling and calculated Hedges’ g effect sizes. Results: GMT⁺ participant ratings and program retention indicated high acceptability. There was no difference between GMT⁺ and BHW on self-reported executive function (g = 0.06). Cognitive tasks suggested benefits of GMT⁺ on information gathering (g = 0.88) and delay-discounting (g = 0.80). Severity of methamphetamine dependence decreased more in GMT⁺ (g = 1.47). Conclusions: GMT⁺ was well-accepted but did not improve self-reported executive functioning. Secondary outcomes suggested GMT⁺ was beneficial for objective cognitive performance and severity of dependence.