Dose-Dependent Relationship Found Between Meth Use and Psychosis Symptoms

There appears to be a large dose-dependent increase in the occurrence of psychotic symptoms during periods of methamphetamine use, according to a study published online in JAMA Psychiatry. Australian researchers found a 5-fold increase in the likelihood of psychotic symptoms during periods of methamphetamine use compared with periods of no use. The increase was strongly dose-dependent: individuals who had used methamphetamine 16 or more days in the prior month were significantly more likely to experience psychotic symptoms than those who had used the drug 15 days or less.

The researchers looked at 278 participants aged 16 or older who met DSM-IV criteria for methamphetamine dependence but did not meet DSM-IV criteria for lifetime schizophrenia or mania. The main outcome measures were clinically significant psychotic symptoms in the prior month, defined as a score of 4 or more on any of the Brief Psychiatric Rating Scale items of suspiciousness, hallucinations, or unusual thought content.

“Although psychotic symptoms appeared to be largely circumscribed to periods of methamphetamine use, the long-term effect of methamphetamine use on a person’s vulnerability to psychosis needs to be better understood,” the researchers said.

For more information about the mental health effects of methamphetamine see Psychiatric News here.

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