Indian Research on Cannabis and Mental Health Reveals High Rates of Psychosis, But Major Gaps in Understanding Why | Research

The takeaway

A systematic review of 52 Indian studies found high co-occurrence of cannabis use and psychotic disorders characterized by positive symptoms, but nearly all studies used male-only samples and none adequately explored the causal relationship.

Readers interested in cannabis and mental health research from non-Western contexts.

All but 1 of 52 Indian cannabis-mental health studies used exclusively male subjects

What the researchers found

The review identified 52 published Indian studies on co-occurring cannabis use disorders and psychiatric conditions. Studies on cannabis and psychosis (n = 16) primarily described acute psychotic episodes with predominant positive symptoms (hallucinations, delusions) following cannabis use.

Six studies observed an overall increased prevalence of all psychiatric disorders among cannabis users, while 14 found high rates of substance use in people already diagnosed with psychiatric conditions. Seven studies examined cognitive effects of cannabis.

A critical limitation across the Indian literature: all studies except one used exclusively male subjects, and only a single study described service delivery models for dual-diagnosis patients. Most research used cross-sectional designs with treatment-seeking populations, leaving fundamental questions about causation, neurobiology, and optimal management unanswered.

Why it matters

India has one of the world's oldest cultural relationships with cannabis (bhang, charas, ganja), and cannabis use is widespread. Understanding the Indian context, where patterns of use, preparations, and cultural attitudes differ from Western settings, adds important diversity to the global cannabis-mental health evidence base. The near-total exclusion of women from Indian cannabis research represents a major knowledge gap.

The numbers in context

52 Indian studies included. 16 on cannabis and psychosis. 14 on substance use among psychiatric patients. 7 on cognitive effects. All but 1 study had all-male subjects. Only 1 study addressed service delivery for dual diagnosis.

How the study worked

Systematic electronic search for published Indian literature on cannabis use disorders and co-occurring psychiatric conditions, conducted in May 2015. 52 English-language articles from India were included.

What this study cannot tell us

Systematic review limited to Indian publications, which may not be indexed in all international databases. Most included studies were observational and cross-sectional. The review was conducted in 2015 and published in 2017, so more recent Indian research is not included. The almost exclusive focus on male subjects severely limits generalizability.

How to read the evidence

Moderate evidence from a systematic review, limited by the quality and design of the underlying Indian studies.

When this study was published

Published in 2017, reviewing Indian literature through 2015.

The bigger picture

India's cannabis-mental health literature mirrors a global pattern: high co-occurrence of cannabis use and psychosis is well-documented, but the causal direction remains unclear. Does cannabis trigger psychosis in vulnerable individuals, or do people developing psychosis self-medicate with cannabis? Indian research, despite its unique cultural context, has not yet answered this question.

Questions still open

How does cannabis use affect Indian women's mental health? Are the traditional cannabis preparations used in India (bhang) associated with different psychiatric outcomes than smoked cannabis? How should Indian mental health services address the dual diagnosis of cannabis use and psychosis?

Common questions

Does cannabis cause psychosis?

This review found that Indian research consistently shows high co-occurrence of cannabis use and psychotic episodes, typically with prominent positive symptoms. However, the review explicitly notes that Indian research has not adequately explored whether cannabis causes psychosis or whether people developing psychosis are drawn to cannabis use.

Is cannabis research in India different from Western research?

India has unique cannabis preparations (bhang, charas) and cultural contexts that differ from Western settings. However, this review found that Indian research arrives at similar conclusions as Western studies: cannabis and psychosis frequently co-occur, cognition may be affected, and the causal mechanisms remain unclear.

Read the original research

A review of Indian research on co-occurring cannabis use disorders& psychiatric disorders.

The Indian journal of medical research, 146(2), 186-195

View on PubMed ↗Publisher’s paper ↗

Citation

Singh, Shalini; Balhara, Yatan Pal Singh. (2017). A review of Indian research on co-occurring cannabis use disorders& psychiatric disorders.. The Indian journal of medical research, 146(2), 186-195. https://doi.org/10.4103/ijmr.IJMR_791_15