Efficacy of Motivational Interviewing in Treating Co-occurring Psychosis and Substance Use Disorder: A Systematic Review and Meta-Analysis

ABSTRACT

Objective: A wealth of evidence has supported the efficacy of motivational interviewing (MI) in reducing substance use as well as other addictive behaviors. In view of the common co-occurrence of substance use disorder among individuals with schizophrenia spectrum disorders, there has been increased attention to applying MI in psychological interventions for individuals with co-occurring psychosis and substance use disorder. This review aims to synthesize the evidence on the efficacy of MI interventions (either as a stand-alone intervention or in combination with other psychological interventions) in reducing substance use and psychotic symptoms.

Data Sources: MEDLINE, PsycINFO, EMBASE, CENTRAL, and CINAHL were searched using keywords related to “psychosis,” “substance addiction,” and “motivational interviewing” to identify studies published in English from 1984 to May 2021.

Study Selection: Of 1,134 articles identified in the literature, we selected 17 studies for review: 5 studies examined stand-alone MI (“MI-pure”), and 13 studies assessed MI as a major treatment component (“MI-mixed”).

Data Extraction: Demographics of participants, intervention characteristics, and outcome data were extracted by the first author and checked by the second author. Random-effects models were used for substance use and psychotic symptom outcomes.

Results: MI-pure interventions did not significantly reduce severity of substance use (g = 0.06, P = .81) or psychotic symptoms (g’s for 2 individual studies = 0.16, P = .54; and 0.01, P = .96). The effect of MI-mixed interventions on substance use decrease was statistically significant but small in size (g = 0.15, P = .048), whereas the effect on psychotic symptom improvement was not significant (g = 0.11, P = .22).

Conclusions: With the caveat that only a small number of comparisons were available for the review on MI-pure interventions, the efficacy of MI in treating co-occurring psychosis and substance use disorder was heterogeneous and modest.