Does propranolol have an antipsychotic effect? A placebo-controlled study in acute schizophrenia

Thirty-six acute schizophrenics were randomly assigned to dextro (d)-propranolol or placebo in a double blind trial lasting four weeks. All patients had a fixed dose of haloperidol during the first week, which resulted in an initial improvement in both groups. Thereafter, a deterioration towards base-line was seen. Six patients on placebo, but none on propranolol were treatment failures at the end of three weeks (P less than 0.001). Comparison of change in scores from week 2 to 4 showed significantly greater deterioration in the placebo group; d-propranolol thus had a better effect than placebo in sustaining the initial improvement with haloperidol. The overall magnitude of clinical change from pre-treatment scores is small, the majority of the patients showing little or no overall improvement. It is concluded that d-propranolol has a detectable therapeutic effect, which by inference must have a novel pharmacological basis, but this is not as potent as standard neuroleptics.