There are two ways to diagnose a disorder: List the symptoms and history, or observe response to treatment. If the patient appears to have schizophrenia but responds exceptionally well to lithium, we would naturally suspect bipolar disorder.
I once proposed studying patients who appear to have schizophrenia—as defined by the leading researchers of the disorder—while treating them with anything but a neuroleptic. The study, if successful, would show similar remission rates (without neuroleptics) among patients with schizophrenia or bipolar disorder. A certain number of patients with bipolar disorder require neuroleptics for stability.
In any case, I believe that true schizophrenia is quite rare and should be considered a diagnosis of exclusion. (Current Psychiatry, March 2006) Most patients diagnosed with schizophrenia have some combination of bipolar disorder, obsessive-compulsive disorder, attention-deficit disorder, panic disorder, and/or seizure disorder. Treating these patients correctly requires much sophistication and creativity while considering all psychotropics with or without neuroleptics.
David Corwin, MD
Paramus, NJ