Long-term amphetamine treatment decreases brain serotonin metabolism: implications for theories of schizophrenia

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Science  21 Sep 1979:
Vol. 205, Issue 4412, pp. 1295-1297
DOI: 10.1126/science.572992


Long-term amphetamine administration to cats (a mean of 8.75 milligrams per kilogram twice daily for 10 days) produced large decreases (40 to 67 percent in serotonin and its major metabolite, 5-hydroxyindoleacetic acid, in all brain regions examined. This treatment also produced several behaviors that are dependent on depressed central serotonergic neurotransmission, and which normally are elicited exclusively by hallucinogenic drugs. Short-term amphetamine administration (15 mg/kg) did not produce these behaviors and resulted in small decreases in brain serotonin and no change in 5-hydroxyindoleacetic acid. These data are discussed in the context of monoamine theories of schizophrenia.