The search for new off-label indications for antidepressant, antianxiety, antipsychotic and anticonvulsant drugs.

Most drugs are prescribed for several illnesses, but it took several years for psychotropic drugs to have multiple clinical indications. Our search for serotonergic drugs in affective illnesses and related disorders led to new off-label indications for fluoxetine, sertraline, tryptophan, clonazepam, alprazolam, tomoxetine, buproprion, duloxetine, risperidone and gabapentin. Various clinical trial designs were used for these proof-of-concept studies. Novel therapeutic uses of benzodiazepines, such as in panic disorder and mania, were found with the introduction of 2 high-potency benzodiazepines, clonazepam and alprazolam, which were thought to have serotonergic properties. Our initial clinical trials of fluoxetine and sertraline led to their approved indications in the treatment of obsessive-compulsive disorder, and our trials of gabapentin led to new indications in anxiety disorders (generalized anxiety, panic attack and social phobia) and sleep disorders (insomnia).