A priming dose (15 mg/kg i.p.) of (+)-amphetamine sulfate combined with a 16 h subcutaneous infusion of 1.36 mg of the drug per hour to rats via its release from osmotic minipumps produced marked decreases in striatal dopamine (DA), dihydroxyphenylacetic acid (DOPAC), homovanillic acid (HVA) and the synaptosomal uptake of [3H]DA which lasted for at least 12 weeks. The decrease in striatal DA persisted through 24 weeks after drug treatment. In contrast, striatal levels of DOPAC, HVA and synaptosomal DA uptake recovered to control levels by 24 weeks after amphetamine treatment.