Pathological laughing and crying : epidemiology, pathophysiology and treatment.

Pathological laughing and crying (PLC) is characterized by frequent, brief, intense paroxysms of uncontrollable crying and/or laughing due to a neurological disorder. When sufficiently frequent and severe, PLC may interfere with the performance of activities of daily living, interpersonal functioning, or both, and is a source of distress for affected patients and their families. PLC is also often misunderstood by patients and their families, and is under-recognized by the clinicians caring for patients with this disorder. However, this syndrome is easily recognized when understood properly and is highly responsive to treatment with a variety of pharmacological agents. This review aims to facilitate the diagnosis and treatment of patients with PLC, and begins by providing definitions of mood and affect that will help clinicians distinguish between mood disorders, such as major depression and mania, and disorders of affect, such as PLC. In addition, the various terms used to describe this syndrome are reviewed and a recommendation for the use of the term PLC is made. The core clinical features of PLC are also presented and the epidemiology of this syndrome is reviewed. A discussion of the pathophysiology of PLC, including the neuroanatomic and neurochemical bases, is provided. Finally, the evaluation and treatment of patients with PLC is described. Based on the pathophysiology of PLC and on a detailed review of published treatment studies, SSRIs are recommended as first-line pharmacotherapy for this disorder. When SSRIs are ineffective or poorly tolerated, other treatment options, including TCAs, noradrenergic reuptake inhibitors, novel antidepressants, dopaminergic agents and uncompetitive NMDA receptor antagonists may be useful second-line treatments.