Let us take an example to clarify the issue. When lithium was first introduced as the treatment of choice in bipolar disorders, there was a great welcome for its wonderful effects, both its anti-manic as well as its prophylactic properties. And justifiably so. Over a period of years, however, the enthusiasm seems to have settled to cautious questioning, and has even given way to skepticism in a number of quarters (Silverstone et al 1998; Gershon and Soares, 1997; Moncrieff, 1995). Even if the US FDA approved only of lithium as prophylactic for bipolar disorders, a number of studies in the last decade find that 20-40% of classical bipolar patients (i.e. ones with clear cut episodes and remissions) show less than desirable response to lithium, or develop undesirable side effects. And amongst the nonclassical cases (like rapid cyclers, dysphoric or mixed states, and the ones with co- morbid substance abuse), the situation is still less satisfactory. Valproate and Olanzapine have been approved by the US FDA as antimanic drugs but not as mood stabilizers. Number of clinicians down the years have switched over to Carbamezapine for its anti-manic, antidepressant as well as  mood stabilizing properties. But now the emphasis seems to be shifting from carbamezapine to the other anticonvulsants, especially in the treatment – resistant cases. Valproate, Lamotrigine, Gabapentin, Topiramate and Tiagabine are the ones holding promise. As also the atypical antipsychotics like Clozapine,Olanzapine, Quetiapine, Ziprasidone, Risperidone and Aripiprazole. (See Grunze and Moller, 2003, for a review of recent work in the field.)