Single photon emission computed tomography (SPECT) with [123I]IMP in the differential diagnosis of psychiatric disorders.

Single photon emission computed tomography (SPECT) with [123I]N-isopropyl iodoamphetamine--[123I]IMP--was used to study regional cerebral blood flow (rCBF) in 94 psychiatric patients and six controls. Patients with dementias had distinct brain-image patterns, consistent with the expected neuropathology. Major depressives had decreased cortical and subcortical rCBF. Increased caudate rCBF was observed in schizophrenics and other psychoses with positive symptoms. SPECT is a practical method of functional brain imaging with potential in the differential diagnosis of neuropsychiatric disorders. Further studies are needed to assess the effect of other variables on brain-image patterns.