Pharmacological approaches to treating negative symptoms: a review of clinical trials.

Clinical trials of pharmacological agents targeting negative symptoms in schizophrenia are reviewed. The focus is on trials that occurred in patients who were stable on an antipsychotic medication at entry to the trial. A small number of trials compared antipsychotics as monotherapy for negative symptoms. Although the data supporting amisulpride for negative symptoms is promising the trials have limitations and it is plausible that the advantages of amisulpride over placebo may result from effects on secondary negative symptoms. Among available agents, antidepressant medications may have effects in negative symptoms. Other promising agents include minocycline, glutamatergic agents, and alpha-7 nicotinic agents. More than 15 active trials are currently underway to evaluate new treatments for negative symptoms.