Background
Up to 64% of individuals who have experienced a first episode of psychosis (FEP) have
used cannabis, and 30% of these have a cannabis use disorder [1, 2]. Cannabis use
among those with FEP is associated with negative outcomes (e.g., positive symptoms,
illness severity) [1]. Given the relationship between cannabis use and psychosis,
and the increasing availability of high potency tetrahydrocannabinol (THC) products,
cannabis use prevention and treatment in people with FEP is a critical issue. Initial
early intervention efforts that address cannabis and other substance use has been
underwhelming. Early intervention programs for FEP generally include evidence-based
practices focused on medication management, family psychoeducation, case management,
individual therapy, and vocational services [3]. Brief or optional cognitive behavioral
therapy for substance use is often integrated in early intervention programs. The
question is, are these interventions sufficient in their intensity and/or duration
to reduce cannabis use?
The answer appears to be no. Young people enrolled in early intervention programs
do not have lower levels of cannabis or other drug use than those who receive treatment
as usual [4]. In a recent secondary data analysis, we found that frequent cannabis
use (> 20 days per month) was higher in those randomized to the early intervention
treatment than those in usual care [5]. These findings are consistent with the treatment
outcomes of general co-occurring disorders. Few interventions for co-occurring disorders
are designed to treat both schizophrenia spectrum and substance use disorders. Most
are focused on improving psychiatric symptoms (e.g., assertive community treatment)
or increasing drug or alcohol abstinence (e.g., contingency management). As a result,
few interventions including contingency management (CM) consistently demonstrate reductions
in both psychiatric symptoms and substance use [6]. Although the addition of CM or
other evidence-based interventions to early intervention programs for FEP is appealing,
truly integrative treatments are needed to improve the lives of young people living
with psychosis and substance use disorders.
Is contingency management (CM) a viable treatment option for early intervention programs?
CM is an evidence-based intervention in which individuals receive tangible rewards
for submitting objective evidence of drug and alcohol abstinence [7]. Our group observed
significantly lower levels of inpatient psychiatric care and psychiatric symptoms
in adult patients with serious mental illness, including schizophrenia, who received
CM for stimulant drug abstinence [8]. We found the CM intervention to be cost-effective,
in part because of reductions in inpatient utilization [9]. The CIRCLE trial, by Rains
et al. [10], was conducted to determine whether or not CM reduced cannabis use and
psychiatric hospitalization, and whether it was cost-effective compared to a psychoeducational
intervention for cannabis use in an early intervention program for FEP. Overall, the
findings equivocally supported positive clinical outcomes that could be attributed
to CM. Interpretation of these results leads us to explore the development of CM or
other approaches as treatments for cannabis use in FEP programs.
Future directions
Findings from the CIRCLE trial raise several considerations for future research. First,
for CM to be effective, the magnitude and frequency of rewards for abstinence must
be sufficient to decrease use. The unique developmental and psychiatric profiles of
those with FEP mean that typical CM schedules might require modification to improve
the intervention efficacy (e.g., more frequent or higher magnitude rewards). Second,
a conclusive trial of CM for cannabis or other substance use requires the combination
of self-report and a biochemically confirmed outcome in both the CM and control groups.
Third, while we have observed CM-associated reductions in psychiatric hospitalizations,
our work investigated treatment as usual in public mental health centers in the USA.
The CIRCLE trial, however, investigated the impact of CM on hospitalizations within
the context of specialized FEP treatment, which is designed to reduce acute psychiatric
care utilization [10]. Thus, it may have been challenging for CM to reduce acute care,
above and beyond that of typical FEP treatment. Fourth, the inclusion of a psychoeducational
intervention focused on cannabis use in the control condition may have had a positive
impact on cannabis use, since use in both groups declined over time. This intervention
might be an effective treatment for cannabis use, and warrants further study. Finally,
the CIRCLE trial raises important questions about the feasibility of CM for FEP programs;
the authors describe the challenges of adding a simple intervention, such as CM, to
an already intensive, multi-component treatment for FEP [10]. Additional work investigating
how CM and other substance use treatments can be implemented in FEP care is greatly
needed.
Conclusions
In the past decade, early intervention programs for FEP have revolutionized the treatment
of schizophrenia. This momentum provides the opportunity to integrate interventions
that address cannabis and substance use problems early in the course of illness, with
the goal of preventing the negative effects of substance use on people with psychosis.
With the increasing availability of high potency THC products, and the global movement
towards decriminalization, cannabis use presents a formidable and important area of
focus for FEP treatment providers. Studies such as the CIRCLE trial indicate that
developing an effective treatment for cannabis use in this population will not be
easy. A one-size-fits-all approach is unlikely to be effective given the homogeneity
of cannabis use (e.g., differences in frequency or motivations for use) in young people
with FEP. Effective strategies are also needed to prevent people with FEP from using
cannabis in the first place. Future research focusing on implementation and dissemination
issues is needed to close the gap between research and practice improvement. As a
field, we should strive to develop truly integrated early interventions for psychosis
and substance use to help improve the lives of young people with, or at high risk
of, these commonly co-occurring disorders.