The research, published inMolecular Psychiatryfound that variations in the gene known as BDNF strongly determine the effects of methamphetamine in the brain. This could potentially explain why some users develop methamphetamine-induced psychosis, which is similar to schizophrenia.

La Trobe neuroscientist Professor Maarten van den Buuse said the research, conducted using animal models, may lead to ways of identifying individuals at particular risk of developing psychosis and could mean a fundamental change in the way the effects of drug-induced psychosis on the brain are treated.

"Drug-induced psychosis is generally treated with anti-psychotic medications, but these are not generally effective and are often associated with side effects," Professor van den Buuse said.

"If further research is able to provide more details on the role genetics plays in the effects of long-term methamphetamine use, we could begin looking at therapies that would make a real difference for people affected by it."

The research looked specifically into the impact of methamphetamine use in adolescence and early adulthood, which is often when long-term users begin taking the drug, Professor van den Buuse said.

The findings are the result of collaboration between academics at La Trobe's School of Psychology and Public Health, and the La Trobe Institute of Molecular Science.