Recent studies suggest that a motivational intervention designed
for individuals with schizophrenia and substance use disorders may
improve substance use and psychiatric outcomes for individuals with
a dual diagnosis. Two recent studies found that brief interventions
incorporating motivational and behavioral techniques to treat substance
use disorders contributed to reductions in substance use among individuals with
schizophrenia spectrum diagnoses (95,96). Specifically, Graeber
et al. (95) found higher abstinence rates among individuals with
schizophrenia and alcohol use disorders who were involved in a three-session
motivational enhancement program relative to those involved in an
educational intervention. Similarly, James et al. (96) found that individuals
involved in a six-session, manualized group intervention with motivational
enhancement and relapse prevention showed greater improvements in
drug-related consequences and reductions in marijuana, alcohol,
and polydrug use at follow-up relative to individuals who attended
a one-session drug education class. Sigmon and Higgins (97) used a
within-subjects reversal design to test the impact of a voucher-based
contingent reinforcement intervention to reduce marijuana use in
seven participants (86% having a schizophrenia diagnosis).
Participants completed 4 weeks of baseline monitoring, during which
they received $10 vouchers per urine specimen independent
of result, followed by 12 weeks of intervention, during which they
received $10 per urine specimen that was negative for marijuana,
followed by another 4 weeks of baseline monitoring. The percentage
of negative tests was significantly greater during the intervention
weeks. However, two studies did not find that involvement in a substance
use intervention contributed to lower rates of substance use (98,99). Although there is variability in research methodology and findings,
motivational and behavioral interventions targeting substance use
for individuals with dual diagnoses appear to be feasible and beneficial.