Chronic MAP abuse may produce a lasting vulnerability of the brain which leads to a paranoid delusional psychosis with hallucinations similar to schizophrenia. This view is based on the clinical observations that duration of the psychotic episodes could last quite long after excretion of MAP in the urine, and that reuse of MAP, alcohol ingestion and nonspecific psychological stressors lead to acute recurrence of psychotic episodes whose clinical features are almost identical to the initial episode in patients with prior MAP psychosis. The experimental studies indicate that a lasting change at the nerve terminal membranes, namely transporters of MAP and dopamine at the uptake sites, in the striatum and nucleus accumbens may be a cause for induction and expression of stimulant-induced sensitization, which may relate to vulnerability to schizophrenia-like psychotic episodes in MAP psychosis.