Lithium Reduces Suicide Rate and Increases Longevity
Suicide is an unfortunate consequence of bipolar disorder in 10-15% of patients. A study by Manchia et al. examined suicidal behavior in 737 families of bipolar patients, including 4,919 first-degree relatives. Suicidal behavior ran in families and was more prevalent in those with an early age of onset and a shorter duration of illness. The good news: lithium treatment decreased suicide risk independent of its degree of effectiveness in treating bipolar disorder. Those on lithium also had a longer median age of survival (73 versus 65 years).
Editor’s Note: These data are consistent with a variety of other studies and raise the question why lithium is used less frequently in the US than in many European countries and Canada. Given its neuroprotective effects, its prevention of suicide and dementia, and its positive effects on longevity, it is hard to see why lithium is not included in the treatment regimens of more patients (at whatever dosage is well-tolerated), even if it alone is not sufficient for treating their manic and depressive episodes.
Research (by this editor Robert Post and colleagues) shows that bipolar disorder is a more pernicious illness in almost all respects in the US compared to the Netherlands and Germany (International Journal of Neuropsychopharmacology, 2011). Whether bipolar illness would be less severe in the US if it were more often treated with lithium is an unanswered question. The field cannot provide an answer with systematic prospective controlled data, as most study designs would be unethical (i.e. would deny useful treatment to suffering patients), although one large randomized comparative study called BALANCE did show the superiority of lithium over valproate. However, individual patients in consultation with their physician could evaluate the evidence and request that lithium be considered in their treatment regimen.
If a patient has some clinical predictors of a likely good response to lithium, the decision to include lithium should be a slam-dunk. Some of these include: a positive family history of mood disorder, especially bipolar disorder; a classic course with distinct episodes and clear periods of wellness; manic episodes that are euphoric as opposed to dysphoric (i.e. anxious/irritable); lack of an anxiety disorder or substance abuse comorbidity; the absence of mood-incongruent delusions; and a sequence of episodes of mania followed by a depression and then a well interval (MDI) rather than the sequence of DMI.
