Current Concepts in the Pharmacotherapy of Pseudobulbar Affect

Arising in settings of CNS insult, pseudobulbar affect (PBA) consists of uncontrollable episodes of crying or laughter incongruent to the patient's mood. The syndrome has been described by a plethora of names, including pathological laughing and crying, emotional lability, emotionalism and emotional incontinence, which hampers efforts to survey published assessments of pharmacological intervention. Still, until quite recently, all treatment has unavoidably been off-label, chiefly involving antidepressants. Using PBA and other syndrome names as search terms, a PubMed search for English-language case reports and therapeutic trials involving at least five patients identified 22 such publications from 1980 through to 2010. Among the seven randomized, double-blind, antidepressant studies with placebo control, two trials assessed 106 and 123 subjects, respectively. However, the other five assessed only 12-28 subjects, and only one of these seven trials (with 28 subjects) measured change in syndrome severity using a validated scale. The three randomized, double-blind studies of dextromethorphan plus quinidine assessed 129, 150 and 326 subjects. Among these studies, two were placebo-controlled and all three used a validated severity scale. Across all placebo-controlled trials, response to active treatment either an antidepressant or dextromethorphan/quinidine has in general been significantly greater than response to placebo, but placebo response has sometimes been substantial, suggesting caution in interpreting uncontrolled findings. In October 2010, dextromethorphan/quinidine received approval from the US FDA as first-in-class PBA pharmacotherapy. Advocates of a continuing role for antidepressants, notably selective serotonin reuptake inhibitors, can point to numerous positive case reports and trials, the potential benefit of attempting to treat PBA and concomitant depression without using multiple drugs, and the ever-present need to tailor treatment to the individual patient.