Abstract:
Schizophrenia affects up to 0.7% of the global population. Recent research highlights a correlation between
psychoactive substance use and the onset of psychotic symptoms, especially in genetically predisposed
individuals, suggesting a potential triggering role of these chemical compounds. To analyze the impact of
psychoactive substance use on the onset of schizophrenia and determine whether this reflects a causal
relationship or a mere coincidence in predisposed individuals. Four studies were analyzed: 7,606 patients with
substance-induced psychosis in Sweden, 115 in Morocco, 150 in Nigeria, and 42,412 methamphetamine users
in California. The substances investigated included cannabis, alcohol, and methamphetamine. Data were
collected from articles published in PubMed and Scopus. In Sweden, 11% of patients with substance-induced
psychosis developed schizophrenia; 18% were cannabis users and 4.7% alcohol users. In California,
methamphetamine users had a 9.4-fold higher risk of developing schizophrenia than the general population. In
Morocco, 37% of schizophrenia patients consumed alcohol and 15% other psychoactive substances. In
Nigeria, 63% had a history of substance use, with men more frequently affected. In all studies, substance use
preceded the onset of psychosis, suggesting a potential triggering role. Psychoactive substance use may act as a
triggering or catalytic factor in schizophrenia. Early intervention and prevention of substance use may reduce
the risk of early onset and improve clinical outcomes, particularly in genetically predisposed individuals.
