Predictors of response to divalproex and lithium

Predictors of response to mood stabilizers are of interest to psychiatrists because patients want and deserve prompt improvement, need to preserve limited hospital benefits, and desire agents that are both efficacious and free of adverse effects. Clinically practical guidelines for the likelihood of lithium responsiveness include mild and uncomplicated illness, pure tannic symptomatology, prior response to lithium, and infrequent episodes. Divalproex has a broader spectrum of responders and has approximately equal benefit for patients with pure mania as for those with several forms of bipolar disorder that respond poorly to lithium (e.g., mixed mania, rapid cycling, comorbid substance abuse, and secondary bipolar disorder). Carbamazepine may be effective in patients who failed to respond to lithium and is more likely to be effective as part of combined drug therapy than as monotherapy. This review points out that, although the number of firm findings regarding predictors of response and the features associated with response are few, many of these can be combined with other general clinical information about the status of the patient to provide a guide to treatment selection and implementation of a therapeutic regimen.