Cannabis-using schizophrenia patients in Asia showed more aggressive behavior

Among Asian patients with schizophrenia, lifetime cannabis use was independently associated with aggressive behavior and was linked to preferential use of long-acting injectable antipsychotics.

Park, Seon-Cheol et al.·Nordic journal of psychiatry·2019·Moderate EvidenceCross-Sectional
RTHC-02218Cross SectionalModerate Evidence2019RETHINKTHC RESEARCH DATABASErethinkthc.com/research

Quick Facts

Study Type
Cross-Sectional
Evidence
Moderate Evidence
Sample
Not reported

What This Study Found

After adjusting for multiple variables, lifetime cannabis use in Asian schizophrenia patients was independently associated with aggressive behavior (aOR 1.58, 95% CI 1.01-2.49) and with long-acting injectable antipsychotic treatment (aOR 1.80, 95% CI 1.44-2.82).

Key Numbers

132 cannabis users vs. 1,756 non-users. Aggressive behavior aOR: 1.58 (95% CI 1.01-2.49, p=.047). Long-acting injectable antipsychotic use aOR: 1.80 (95% CI 1.44-2.82, p=.001).

How They Did This

Cross-sectional analysis of the REAP-AP consortium survey, which collected psychotropic prescription patterns from Asian schizophrenia patients. Compared 132 lifetime cannabis users with 1,756 non-users using binary logistic regression, adjusting for age, sex, region, income, duration of untreated psychosis, and comorbidity.

Why This Research Matters

Most cannabis-psychosis research comes from Western populations. This large multi-country Asian dataset provides evidence that the cannabis-aggression link in schizophrenia extends across cultural contexts.

The Bigger Picture

The finding that cannabis-using patients were more likely to receive long-acting injectable antipsychotics suggests clinicians may be responding to treatment adherence or behavioral management challenges associated with cannabis use.

What This Study Doesn't Tell Us

Cross-sectional design cannot establish causation. Cannabis use was based on lifetime self-report. The cannabis-using group was much smaller than the non-using group. Cultural factors around cannabis use in Asia may limit generalizability.

Questions This Raises

  • ?Is cannabis causing the aggressive behavior, or are more aggressive patients more likely to seek out cannabis?
  • ?Does cannabis cessation reduce aggressive episodes?
  • ?Why are long-acting injectables preferentially used in this group?

Trust & Context

Key Stat:
1.58x higher odds of aggressive behavior with cannabis use
Evidence Grade:
Moderate: large multi-country consortium with appropriate statistical controls, but cross-sectional design.
Study Age:
Published in 2019.
Original Title:
Cannabis use correlates with aggressive behavior and long-acting injectable antipsychotic treatment in Asian patients with schizophrenia.
Published In:
Nordic journal of psychiatry, 73(6), 323-330 (2019)
Database ID:
RTHC-02218

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

Does this prove cannabis causes aggression in schizophrenia?

No. The study found an association between lifetime cannabis use and aggressive behavior, but the cross-sectional design cannot determine which came first or prove causation.

What are long-acting injectable antipsychotics?

These are antipsychotic medications given as injections every few weeks instead of daily pills. They are often used when medication adherence is a concern.

Read More on RethinkTHC

Cite This Study

RTHC-02218·https://rethinkthc.com/research/RTHC-02218

APA

Park, Seon-Cheol; Oh, Hong Seok; Tripathi, Adarsh; Kallivayalil, Roy Abraham; Avasthi, Ajit; Grover, Sandeep; Tanra, Andi Jayalangkara; Kanba, Shigenobu; Kato, Takahiro A; Inada, Toshiya; Chee, Kok Yoon; Chong, Mian-Yoon; Lin, Shih-Ku; Sim, Kang; Xiang, Yu-Tao; Tan, Chay Hoon; Javed, Afzal; Sartorius, Norman; Shinfuku, Naotaka; Park, Yong Chon. (2019). Cannabis use correlates with aggressive behavior and long-acting injectable antipsychotic treatment in Asian patients with schizophrenia.. Nordic journal of psychiatry, 73(6), 323-330. https://doi.org/10.1080/08039488.2019.1632381

MLA

Park, Seon-Cheol, et al. "Cannabis use correlates with aggressive behavior and long-acting injectable antipsychotic treatment in Asian patients with schizophrenia.." Nordic journal of psychiatry, 2019. https://doi.org/10.1080/08039488.2019.1632381

RethinkTHC

RethinkTHC Research Database. "Cannabis use correlates with aggressive behavior and long-ac..." RTHC-02218. Retrieved from https://rethinkthc.com/research/park-2019-cannabis-use-correlates-with

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.