Uncontrollable Crying or Laughing: What’s Behind Pseudobulbar Affect?

 

Pharmacologic Treatment for PBA

Until recently, pharmacologic intervention for PBA consisted of off-label agents, primarily antidepressants (notably, selective serotonin reuptake inhibitors [SSRIs]).¹ “I have also seen patients with PBA treated with antipsychotics, benzodiazepines, and anticonvulsants,” Crumpacker reported.

Dextromethorphan hydrobromide/quinidine sulfate (DM/Q, brand name Nuedexta) is the only FDA drug approved specifically for PBA. Dextromethorphan is an uncompetitive N-methyl-d-aspartate (NMDA) glutamate receptor antagonist, a sigma-1 receptor agonist, and a serotonin and norepinephrine reuptake inhibitor.

Quinidine, a cytochrome P450 2D6 inhibitor, is coadministered to block DM hepatic metabolism, resulting in increased DM bioavailability.⁵ Sigma-1 receptors are densely distributed in areas governing emotional expression, such as limbic and motor regions of the brain, brainstem, and cerebellum.¹ SSRIs remain a reasonable option in cases of comorbid PBA and depression or anxiety, if DM/Q is contraindicated due to potential side effects or risk of drug-drug interactions.¹

Nonpharmacologic Interventions

Patient education is important, Alexopoulos emphasized. “You can also educate the patient’s family how not to get devastated when they see their loved one crying because they understand PBA is a transient neurological phenomenon and is not reflective of mood or psychosis.”

Education is also important because you are separating out the person’s behavior from the neurological damage causing it, Crumpacker added.  “Behavioral pathology really impacts the lives of patients and families,” he observed. “People usually do not get divorced because a spouse is ill, but might get divorced because of the behaviors and personality changes caused by the illness.”

Additional nonpharmacologic interventions include cognitive-behavioral therapy for PBA^6,7 and support groups, which can “provide therapeutic benefits, including socialization, support, education, a sense of control over the illness, and a chance to keep active,” according to geriatric psychiatrist Edward C. Lauterbach, MD.⁸

Conclusion

“As a psychiatrist, always consider PBA when patients with neurologic conditions start behaving bizarrely, or when a patient presents with spontaneous and incongruous laughter or tears,” Crumpacker said. Make appropriate referrals to neurologists, psychologists and other professionals, and provide the patient and family with education and emotional support.

Batya Swift Yasgur MA, LMSW, is a psychotherapist and freelance writer who lives in Teaneck, N.J. She practices therapy in New York City.

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