Methamphetamine enhances the development of schizophrenia in first-degree relatives of patients with schizophrenia

Although there is some evidence that methamphetamine (MA) abuse may play a causative role in the development of schizophrenia, studies directly linking these 2 are rare.

In our study, the effect of MA abuse on the development of schizophrenia was investigated in 15 MA abusers who are offspring of patients with schizophrenia and 15 siblings of MA abusers without a history of drug abuse. Cognitive deficits and resting-state brain function were evaluated in all participants. Correlations between cognitive deficits and schizophrenia development were investigated.

Significantly more cognitive impairments were observed in MA abusers, compared with their siblings without a history of drug use. Significant abnormalities in regional homogeneity (ReHo) signals were observed in resting brain in MA abusers. Decreased ReHo was found to be distributed over the bilateral cingulate gyrus, right Brodmann area 24, and bilateral anterior cingulate cortex. Seven MA abusers were diagnosed with schizophrenia, while 1 control sibling was diagnosed with schizophrenia during the 5-year follow-up. The cognitive scores correlated with the development of schizophrenia in MA abusers.

Our study provides direct evidence for the causative role of MA use in the etiology of schizophrenia and highlights the role of MA-induced brain abnormalities in cognitive deficiency and development of schizophrenia.