Pseudobulbar affect (PBA) is a neurologic condition that causes sudden, uncontrollable episodes of crying or laughing that do not match how a person actually feels. It usually happens in people living with another neurologic condition, such as ALS, multiple sclerosis, stroke, Alzheimer disease, Parkinson disease or a traumatic brain injury.
This guide covers what PBA looks like, why it happens, how it is diagnosed and the one medicine the FDA has approved to treat it.
This information is educational and does not replace advice from your own healthcare provider. Never start, stop or change a medicine without talking to your prescriber.
What Is Pseudobulbar Affect?
Pseudobulbar affect is a disorder of emotional expression in which a person cries or laughs suddenly and uncontrollably, out of proportion to what they are feeling or to what is happening around them.
The FDA prescribing information for Nuedexta describes PBA as involuntary, sudden and frequent episodes of laughing and/or crying that are out of proportion to, or do not match, the person’s underlying emotional state. A person may cry at a mildly sad moment, laugh at something that is not funny, or even switch from one to the other, and find it very hard to stop.
What Are the Symptoms of Pseudobulbar Affect?
The main symptom of PBA is uncontrollable crying or laughing that comes on suddenly and does not reflect how the person feels inside.
- Crying or laughing episodes that start suddenly and are hard or impossible to stop
- Reactions that are much stronger than the situation calls for
- Laughing in sad situations, or crying in situations that are not sad
- Episodes that are brief, often lasting seconds to minutes
- Feeling embarrassed or avoiding social situations because of the episodes
Because the episodes can be disruptive and embarrassing, a published review in Therapeutics and Clinical Risk Management describes PBA as under-recognized and linked to a real social burden for patients and caregivers.
What Causes Pseudobulbar Affect?
Pseudobulbar affect is caused by damage to the brain pathways that normally keep emotional expression under voluntary control, which happens as part of certain neurologic diseases and injuries.
Researchers describe PBA as a loss of voluntary control, or disinhibition, involving circuits that connect the brain’s outer layer (cortex) with the brainstem and cerebellum. The brain chemicals serotonin and glutamate are thought to play a role. The conditions most often linked to PBA include:
- Amyotrophic lateral sclerosis (ALS)
- Multiple sclerosis (MS)
- Stroke
- Traumatic brain injury
- Alzheimer disease and other dementias
- Parkinson disease
How Common Is Pseudobulbar Affect?
A nationwide US survey of people with six neurologic conditions found PBA symptoms in 9.4% to 37.5% of them, which researchers estimated at 1.8 million to 7.1 million Americans.
These figures come from the review by Ahmed and Simmons (2013). Estimates vary widely from study to study depending on which condition is studied and which screening tool and cutoff are used.
Prevalence numbers are research estimates based on survey screening. They are not a diagnosis and may not reflect current rates.
Pseudobulbar Affect vs Depression: What Is the Difference?
PBA episodes are brief bursts of crying or laughing that do not match a person’s mood, while depression is a lasting low mood that usually continues for weeks or months.
| Pseudobulbar affect | Depression | |
|---|---|---|
| How long it lasts | Seconds to minutes per episode | Weeks to months |
| Match with inner feelings | Expression does not match how the person feels | Crying reflects a truly low mood |
| Other features | Usually no changes in sleep or appetite from PBA itself | Often includes sleep, appetite and energy changes |
The Ahmed and Simmons review notes that most people with PBA are not depressed. The two can also happen together, which is why a clinician should make the call.
How Is Pseudobulbar Affect Diagnosed?
PBA is diagnosed by a clinician, usually a neurologist, based on the person’s history and a description of the episodes, sometimes supported by a short screening questionnaire.
Two tools described in the medical literature are the Center for Neurologic Study-Lability Scale (CNS-LS), a seven-question self-report questionnaire, and the Pathological Laughing and Crying Scale (PLACS), an 18-question interview done by a clinician. Studies have used a CNS-LS score of 13 or higher as a screening cutoff in ALS and 17 or higher in MS. A screening score alone does not confirm PBA.
How Is Pseudobulbar Affect Treated?
The only medicine FDA-approved to treat pseudobulbar affect is dextromethorphan and quinidine, sold as Nuedexta and available as a generic.
Nuedexta was approved in October 2010. Its main 12-week clinical trial enrolled 326 adults with PBA who also had ALS (about 60%) or MS (about 40%). People taking Nuedexta had statistically significantly fewer laughing and crying episodes than people taking a placebo, according to the FDA prescribing information. Results in one study cannot predict how any individual will respond.
Some doctors also prescribe certain antidepressants, such as SSRIs or tricyclic antidepressants, for PBA. This is off-label use: none of these medicines is FDA-approved to treat PBA.
Learn more about generic Nuedexta, its cost, dosing and side effects.
This information is educational and does not replace advice from your own healthcare provider. Never start, stop or change a medicine without talking to your prescriber.
Getting Help Paying for PBA Treatment
Patients prescribed Nuedexta or generic dextromethorphan and quinidine may be able to lower their costs through a manufacturer copay card, patient assistance or foundation grants, depending on their insurance.
QuickRx Specialty Pharmacy applies for these on your behalf at no cost to you, and eligible patients may pay $0. See Nuedexta copay assistance or call (917) 830-2525.
Assistance availability, eligibility and savings depend on each program’s own rules and your insurance, and approval is not guaranteed. QuickRx applies on your behalf and does not issue copay cards or grants.
Frequently Asked Questions About Pseudobulbar Affect
Is pseudobulbar affect a mental illness?
Pseudobulbar affect is a neurologic condition linked to damage in the brain pathways that control emotional expression.
It happens in people who already have a neurologic disease or injury, such as ALS, multiple sclerosis, stroke or traumatic brain injury. A published review notes that most people with PBA are not depressed, even though the crying can look like depression from the outside.
What are other names for pseudobulbar affect?
Pseudobulbar affect has been called emotional lability, emotional incontinence, pathological laughing and crying, emotionalism and involuntary emotional expression disorder.
These different names are one reason PBA can be hard to research and easy to miss.
Can pseudobulbar affect go away on its own?
PBA can improve on its own in some people, which is why prescribers are advised to check periodically whether treatment is still needed.
How PBA changes over time depends largely on the underlying neurologic condition. Your neurologist is the best person to judge your own outlook.
Is there a generic medicine for pseudobulbar affect?
Yes. Generic dextromethorphan and quinidine is available in the US in the same 20 mg / 10 mg capsule strength as brand-name Nuedexta, according to Lexidrug.
See our generic Nuedexta cost guide for published prices and how the generic compares with the brand.
Can children take Nuedexta for PBA?
The safety and effectiveness of Nuedexta have not been established in patients under 18, according to its FDA prescribing information.
What should I do if I think I have PBA?
Talk to your neurologist or primary care provider and describe how often the episodes happen, how long they last and whether they match how you feel inside.
Keeping a short log of episodes before your visit can help your provider decide whether a screening questionnaire such as the CNS-LS is appropriate.
References
- Nuedexta (dextromethorphan hydrobromide and quinidine sulfate) prescribing information. DailyMed, U.S. National Library of Medicine.
- Ahmed A, Simmons Z. Pseudobulbar affect: prevalence and management. Ther Clin Risk Manag. 2013;9:483-489. PubMed Central, National Institutes of Health.
- Lexidrug (UpToDate Lexidrug, Wolters Kluwer Health). Dextromethorphan and Quinidine monograph. Last Updated 9/25/26. Includes Pricing: US data from Medi-Span.
- MedlinePlus: Dextromethorphan and Quinidine. U.S. National Library of Medicine.
Medical Disclaimer: This article is for educational purposes only and does not replace professional medical advice, diagnosis or treatment. Always talk with your neurologist, primary care provider or pharmacist about your own condition and treatment. Drug information is current as of September 25, 2026 and may change. Statistics describe groups of people studied and cannot predict any one person’s experience.
