Cannabis use did not predict negative beliefs about antipsychotic medications

Among 265 patients with first-treatment psychosis, cannabis use was not associated with negative beliefs about antipsychotic medications, suggesting other factors explain poor medication adherence in cannabis-using patients.

Gjerde, Priyanthi B et al.·Frontiers in psychiatry·2022·Moderate EvidenceCross-Sectional
RTHC-03875Cross SectionalModerate Evidence2022RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Moderate Evidence
Sample
N=265

What This Study Found

Neither lifetime cannabis use, current use, nor cannabis abuse diagnosis was associated with negative beliefs about medicines as measured by the BMQ questionnaire. However, patients with lifetime cannabis use were more likely to be male, younger at psychosis onset, and have higher alcohol and tobacco use.

Key Numbers

265 first-treatment psychosis patients. Cannabis users were younger at onset, more likely male, higher alcohol and tobacco use. No significant association between any cannabis measure and BMQ scores.

How They Did This

Cross-sectional study of 265 patients with first-treatment schizophrenia spectrum disorder. Cannabis use assessed across three measures (lifetime, current, abuse/addiction). Medication beliefs measured using the validated Beliefs about Medication Questionnaire (BMQ). GLM analyses controlled for age and sex.

Why This Research Matters

Cannabis use predicts poor medication adherence in psychosis patients. If not through negative medication beliefs, clinicians need to identify the actual barriers to compliance in cannabis-using patients.

The Bigger Picture

The null finding is informative: it redirects the search for why cannabis-using psychosis patients have poor medication adherence toward other mechanisms like forgetting, side effect sensitivity, or competing priorities.

What This Study Doesn't Tell Us

Cross-sectional design. Self-reported cannabis use. BMQ may not capture all dimensions of medication attitudes relevant to this population.

Questions This Raises

  • ?If not beliefs, what drives poor medication adherence in cannabis-using psychosis patients?
  • ?Could intoxication-related forgetting or lifestyle factors be more important?

Trust & Context

Key Stat:
No association between cannabis use and negative medication beliefs
Evidence Grade:
Well-designed clinical study with validated instruments, though cross-sectional design limits causal inference.
Study Age:
Published in 2022.
Original Title:
Lifetime Cannabis Use Is Not Associated With Negative Beliefs About Medication in Patients With First Treatment Psychosis.
Published In:
Frontiers in psychiatry, 13, 824051 (2022)
Database ID:
RTHC-03875

Evidence Hierarchy

Meta-Analysis / Systematic Review
Randomized Controlled Trial
Cohort / Case-Control
Cross-Sectional / ObservationalSnapshot without intervening
This study
Case Report / Animal Study

A snapshot of a population at one point in time.

What do these levels mean? →

Frequently Asked Questions

Do cannabis-using psychosis patients dislike their medications more?

No. This study found no link between cannabis use and negative beliefs about antipsychotic medications, despite cannabis use being known to predict poor medication adherence in this population.

Why do cannabis-using patients still have worse adherence?

The study suggests other factors beyond medication beliefs drive poor adherence in cannabis users with psychosis, such as lifestyle factors, cognitive effects of cannabis, or competing priorities.

Read More on RethinkTHC

Cite This Study

RTHC-03875·https://rethinkthc.com/research/RTHC-03875

APA

Gjerde, Priyanthi B; Steen, Synne W; Vedal, Trude S J; Steen, Nils Eiel; Reponen, Elina J; Andreassen, Ole A; Steen, Vidar M; Melle, Ingrid. (2022). Lifetime Cannabis Use Is Not Associated With Negative Beliefs About Medication in Patients With First Treatment Psychosis.. Frontiers in psychiatry, 13, 824051. https://doi.org/10.3389/fpsyt.2022.824051

MLA

Gjerde, Priyanthi B, et al. "Lifetime Cannabis Use Is Not Associated With Negative Beliefs About Medication in Patients With First Treatment Psychosis.." Frontiers in psychiatry, 2022. https://doi.org/10.3389/fpsyt.2022.824051

RethinkTHC

RethinkTHC Research Database. "Lifetime Cannabis Use Is Not Associated With Negative Belief..." RTHC-03875. Retrieved from https://rethinkthc.com/research/gjerde-2022-lifetime-cannabis-use-is

Access the Original Study

Study data sourced from PubMed, a service of the U.S. National Library of Medicine, National Institutes of Health.

This study breakdown was produced by the RethinkTHC research team. We analyze and report published research findings without making health recommendations. All interpretations are based solely on the published abstract and study data.