Meth & Marijuana Use Can Lead to Schizophrenia

by Mike Miller January 29, 2012

If you needed one more reason not to start taking crystal meth how about this – it can increase your chances of suffering from schizophrenia.

According to, researchers in Toronto, Canada have found evidence that heavy methamphetamine users might have a higher risk of developing schizophrenia.

This finding was based on a study comparing the risk among methamphetamine users not only to a group that did not use drugs, but also to heavy users of other drugs.

Methamphetamine and other amphetamine-type stimulants are the second most common type of illicit drug used worldwide.

People hospitalized for methamphetamine dependence that did not have a diagnosis of schizophrenia or psychotic symptoms at the start of our study period had an approximately 1.5 to 3.0-fold risk of subsequently being diagnosed with schizophrenia, compared with groups of patients who used cocaine, alcohol or opioid drugs. 

They also found that the increased risk of schizophrenia in methamphetamine users was similar to that of heavy users of cannabis (marijuana).

Researchers examined California hospital records of patients admitted between 1990 and 2000 with a diagnosis of dependence or abuse for several major drugs, including methamphetamine, cannabis, alcohol, cocaine or opioids. They also included a control group of patients with appendicitis and no drug use. The methamphetamine group had 42,412 cases, while cannabis had 23,335.

There has been a longstanding debate as to whether there is a connection between methamphetamine use and schizophrenia. In Japan, experts believe that methamphetamine might cause a schizophrenia-like illness, based on their observations of high rates of psychosis among methamphetamine users admitted to psychiatric hospitals.

Drugs are bad. Nothing good can come from the use of illicit drugs. If you or someone you care about has a drug problem, please seek help. If you prefer to maintain total anonymity, there are online drug classes too.

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