Treatment of pathologic laughing and crying.

Pathologic laughing and crying (PLC) denotes paroxysms of involuntary and uncontrollable crying and/or laughing resulting from neurologic illnesses. These paroxysms of affect are often provoked by nonsentimental stimuli; even when the inciting stimulus is sentimentally meaningful, the intensity of the affective response is excessive. The crying and/or laughing of PLC are variably accompanied by episode-congruent subjective emotional feelings. In unusual cases, episode-related feelings are of a valence contradictory to the expressed affect (ie, feeling happy while crying, or vice versa). PLC does not bear a predictable relationship to the prevailing mood of the patient, and the occurrence of such episodes does not produce a sustained mood disturbance. Therefore, patients with PLC must not be misunderstood as "depressed" or "manic" solely on the basis of their frequent episodic crying or laughing. In rare circumstances, PLC or PLC-like symptoms may be the presenting symptom of a neurologic illness. In such circumstances, a prompt and thorough diagnostic evaluation for that neurologic illness should be undertaken before initiating treatment for PLC. Selective serotonin reuptake inhibitors (SSRIs) are efficacious, safe, and well-tolerated treatments for PLC and are recommended as first-line treatments for this condition. Tricyclic antidepressants, dextromethorphan/quinidine, or dopaminergic agents may be useful alternative treatments in patients in whom SSRIs are ineffective or poorly tolerated. Education and supportive therapy may help patients and families mitigate the social isolation and embarrassment that PLC episodes frequently produce.