[quote][u]Drug abuse[/u] Drugs do not directly cause schizophrenia, but studies have shown drug misuse increases the risk of developing schizophrenia or a similar illness. Certain drugs, [u]particularly cannabis,[/u] cocaine, LSD or amphetamines, may trigger some symptoms of schizophrenia, especially in people who are susceptible. Using amphetamines or cocaine can lead to psychosis and can cause a relapse in people recovering from an earlier episode. Three major studies have shown teenagers under 15 who use cannabis regularly, especially ‘skunk’ and other more potent forms of the drug, are up to four times more likely to develop schizophrenia by the age of 26.[/quote]