Double blind controlled trials of cholecystokinin octapeptide in neuroleptic-refractory schizophrenia

A group of 14 schizophrenics who remained symptomatic after neuroleptic treatment received either 0.02 mcg/kg CCK-8 or saline placebo intravenously. Thereafter, 13 received the alternative infusion as a crossover treatment. A second group of 16 such patients received 0.04 mcg/kg CCK-8 or saline intravenously and, thereafter, 14 of these received the alternative infusion as a crossover treatment. Psychopathology was rated prior to, 2-3 h post, and on days 3, 5 and 7 after each infusion. Ratings consisted of the BPRS, the Abrams and Taylor Scale for Emotional Blunting, the Hamilton Anxiety Scale and a Schneiderian "Positive" symptom scale abstracted from the President State Examination. Parallel groups and cross over design analyses failed to show efficacy for CCK-8.