The benefits of standard Mood Stabilizers (MS) in Bipolar Illness type I are very clear.
In other Bipolar spectrum illness (not type I), a low dose of MS, especially lithium and valproate may be also particularly important, although those patients frequently do not want to take these mood stabilizers owing to the fact that they usually have not experienced mania.
Yet it is important to recognize that most of the research on therapeutic blood levels for lithium and valproate are limited to acute mania. These “therapeutic” levels may not apply in other circumstances such as patients who do not have bipolar disorder type 1 (i.e., acute mania). Thus, there is a discussion of what appropriate mood stabilizer blood levels would be for these patients. There are very few data to rely on here. In one study, over 80% of patients with cyclothymia responded to a mean level of valproate of 32.5 mg/dL. It seems to me that it may not be unreasonable to try low-dose valproate or lithium initially in patients who might meet our criteria for bipolar spectrum disorder. If patients respond, they can avoid the increased side effects associated with higher levels. If patients do not respond, the doses can be raised to full therapeutic levels. If the patient objects or refuses, the standard mood stabilizers can be dropped in favor of the novel anticonvulsants.