Calcium channel inhibitors (CCI) are thought to affect calcium flux through membrane-bound channels as their major site of action. Reports of clinical trials involving over 150 patients suggest that CCIs also have beneficial effects in neuropsychiatric disorders. Each of the 4 major subclasses of CCIs appears to have unique combinations of biochemical and behavioral properties. Additional studies have suggested a complex interaction between dopamine receptor function and calcium channels. We have completed a study of the clinical effects of verapamil in a schizophrenic population where trends toward improvement did not reach statistical significance. We have proceeded with the protocol to examine the effects of nifedipine in a similar cohort.
