Cannabis occupies a strange place in the public conversation — treated by some as essentially harmless and by others as a dangerous drug, with the actual clinical evidence often lost somewhere in between. My aim here is neither to alarm nor to reassure, just to lay out what the research actually shows about cannabis and mental health.
Can Cannabis Trigger Psychosis?
Evidence links cannabis use to earlier onset of psychosis in people with genetic risk factors for psychotic disorders, including schizophrenia, as well as worse symptoms in people who already have these conditions.[1] Cannabis intoxication can also induce a temporary psychotic episode in some people, particularly at high doses, and experiencing such an episode has been linked with a higher likelihood of developing a psychotic disorder later in life.[1]
A large cohort study found that adolescent cannabis use was associated with more than double the risk of developing a psychotic disorder, and roughly double the risk of developing bipolar disorder, by age 26.[2]
What I try to convey to patients isn't "cannabis is dangerous for everyone" — that's not accurate either. It's that some people carry a vulnerability they don't know about until cannabis interacts with it, and by then the psychotic episode has already happened. There's no reliable way to know your own risk in advance, which is exactly why the population-level evidence matters even for someone who's used cannabis without problems so far.
Why Is Adolescent Use Especially Risky?
The teen brain is actively developing and continues to do so until around age 25, and cannabis use during adolescence and young adulthood may harm this developing brain.[3] Long-term cannabis use initiated during adolescence is associated with a decline in IQ scores and cognitive performance, and high-THC exposure can affect brain regions governing decision-making, impulse control and emotional regulation.
Cannabis use has also been linked to a range of mental health problems in teens, including depression and social anxiety, along with an increased likelihood of not completing high school or college.[3]
Is Cannabis Addictive?
Research has found the prevalence of cannabis use disorder to be higher in regions with more permissive cannabis laws, and increased risks of addiction are specifically linked to ultra-high-potency products now common in the market. This doesn't mean everyone who uses cannabis becomes dependent, but the "it's not addictive" narrative doesn't hold up against the clinical evidence.
Patients who use cannabis regularly are often surprised when I ask about cannabis use disorder symptoms — many assume dependence isn't really possible with a "natural" substance. The pattern I see clinically looks a lot like other substance use disorders: escalating use, difficulty cutting down despite wanting to, and withdrawal symptoms like irritability and sleep disruption when they try to stop.
What Does Treatment Involve?
- Behavioural therapy: Cognitive behavioural approaches remain the primary evidence-based treatment for cannabis use disorder, since no FDA-approved medication yet exists specifically for it
- Treating co-occurring symptoms directly: Psychotic symptoms, anxiety, or depression linked to cannabis use need their own targeted psychiatric treatment, not just cessation of use alone
- Honest risk assessment: Understanding personal and family psychiatric history helps clarify individual risk, particularly relevant for anyone with a family history of psychosis or bipolar disorder
"The goal isn't to moralise about cannabis — it's to make sure people are making that choice with accurate information about the actual risk to their mental health."
— Dr. Varun Gupta
Frequently Asked Questions
Does cannabis actually cause psychosis or schizophrenia?
Cannabis use is linked to earlier onset of psychosis in people with genetic risk factors, and heavy adolescent use is associated with a significantly increased risk of a psychotic disorder. It's a genuine, well-documented risk factor, particularly for vulnerable individuals or those who start young.
Is cannabis addictive?
Yes, cannabis use disorder is a recognised clinical diagnosis, and risk rises with earlier first use, higher THC potency, and more frequent use.
Is it more dangerous for teenagers than adults?
Yes. The brain continues developing until around age 25, and adolescent cannabis use is linked to meaningfully higher risk of psychotic, bipolar, depressive and anxiety disorders by adulthood, along with effects on memory, learning and IQ.
References
- National Institute on Drug Abuse. Cannabis (Marijuana). nida.nih.gov/research-topics/cannabis-marijuana
- PMC / JAMA Health Forum. Adolescent Cannabis Use and Risk of Psychotic, Bipolar, Depressive, and Anxiety Disorders. pmc.ncbi.nlm.nih.gov/articles/PMC12924094
- Centers for Disease Control and Prevention. Cannabis and Teens. cdc.gov/cannabis/health-effects/cannabis-and-teens.html
Ready to take the first step?
Book a confidential consultation with Dr. Varun Gupta — MBBS, MD Psychiatry, Jammu.
300/1 Channi Himmat, Jammu
Shop No. 3, Near CHCH Katra, Counter No. 2