The Functional-Cognitive and Sensory Treatment (F-CaST) to improve rehabilitation outcomes of individuals with substance use disorder: a study protocol for a mixed-method randomized controlled trial

Background: Substance use disorder (SUD) is associated with executive function (EF) deficits and sensory modulation dysfunction (SMD). Yet, these deficits are not addressed therapeutically. This study aims to examine the effectiveness of the Functional-Cognitive and Sensory Treatment (F-CaST) compared to standard care to improve everyday performance and behavior and length of stay at the therapeutic community (TC) in individuals with SUD. In addition, to assess the improvement in EF, sensory modulation, participation, self-efficacy, life satisfaction, and use of strategies within and between groups. Satisfaction with F-CaST will also be assessed. Methods: Forty-eight participants from a community of men in a TC, aged 18–45 years will be randomly allocated to (i) F-CaST—(experimental group) providing sensory and EF strategies for improving daily function; (ii) standard care (control group) as provided in the TC. Assessments will be conducted by assessors blind to group allocation at 4 time points: T1- pre-intervention; T2- post-intervention; T3- 1-month follow-up; and T4- 3-month follow-up. Primary outcome measures will be everyday performance, assessed by the Canadian Occupational Performance Measure (COPM), behavior and length of stay in the TC; secondary outcome measures will assess EF, SMD. Semi-structured in-depth qualitative interviews will be conducted at T1, T2 and T4. Discussion: We hypothesize that F-CaST will lead to improved everyday performance and longer length of stay in the TC, compared to the control group. If F-CaST will prove to be effective, cognitive and sensory strategies may be incorporated as an adjunctive intervention in SUD rehabilitation. Trial registration: ClinicalTrials.gov NCT05647863 Registered on 13 December 2022, https://classic.clinicaltrials.gov/ct2/show/NCT05647863.