Pseudobulbar affect (PBA) involves brief, uncontrolled episodes of crying or laughing that can occur due to various neurological conditions, such as stroke or multiple sclerosis (MS). This symptom can affect a person’s relationships, work, and quality of life.

The estimated prevalence of PBA among people with neurological disorders in the United States ranges from 9.4% to 37.5%. This means that between 1.8 and 7.1 million Americans experience PBA.

Diagnosing the condition may involve using scales that quantify the symptoms, such as the Pathological Laughter and Crying Scale. Treatment includes drugs that help normalize levels of neurotransmitters in the brain that are too high or too low.

This article examines the symptoms, causes, diagnosis, treatment, outlook, and complications of pseudobulbar affect. It also discusses coping and support.

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PBA involves involuntary, brief episodes of crying or laughing. A person cannot control them, and the episodes are not due to a mental health condition.

Someone with PBA may not feel the emotions they are expressing. They can also feel unusually sad or happy even when the episodes are not happening.

PBA is a secondary effect of many neurological disorders, the most common of which include:

PBA can also occur as part of pseudobulbar palsy, a condition that occurs due to stroke and other brain injuries.

Doctors can mistake PBA for depression or bipolar disorder. However, PBA is not a mental health condition. It is the result of a neurological disorder that has caused damage to the brain.

That said, people with neurological conditions can also experience depression, so it can be difficult for others to distinguish between the two. PBA itself can also be challenging to live with. For this reason, it is important for anyone having unexplained bouts of crying to speak with a doctor.

A 2020 analysis of stroke survivors and caregivers found that many of the doctors they interacted with during diagnosis and treatment had a low awareness of what PBA is.

If a person is having difficulties getting information about PBA and whether they or a loved one might have it, they can seek a second opinion from a doctor with more knowledge on the subject.

PBA causes sudden, short emotional reactions that may include:

  • crying
  • laughing
  • a mixture of both

Episodes can last several seconds to several minutes. They are unpredictable and can occur in response to a trigger, such as a slightly amusing or sad situation. They can even occur without an apparent trigger. The severity may range from mild to seizure-like episodes.

People with PBA symptoms may find these episodes embarrassing, confusing, and frustrating. The condition can affect a person’s work, relationships, and quality of life.

If someone has pseudobulbar palsy, they may also experience:

  • weakness in the face and mouth
  • difficulty speaking clearly
  • difficulty swallowing

PBA can occur as a result of many neurological conditions. However, it generally stems from a disruption in the connections between parts of the brain responsible for controlling emotional expression.

The frontal lobe communicates with other areas of the brain to mediate emotional responses, including parts of the cerebral cortex and the cerebellum. The degeneration of the neurons that connect these regions can result in a lack of control over a person’s emotional expression.

High or low levels of certain neurotransmitters may also play a role in PBA development. Neurotransmitters are chemicals that transfer impulses from one nerve fiber to another. In PBA, there may be a decrease in serotonin or dopamine or an increase in glutamate. However, scientists are still learning about this.

Clinicians often diagnose PBA informally as part of a neurological evaluation. Doctors may ask questions about a person’s symptoms or use a scale that objectively quantifies a person’s atypical emotional responses. Examples of these scales include The Center for Neurologic Study–Lability Scale and the Pathological Laughter and Crying Scale.

If a doctor suspects PBA and a person does not already have a diagnosis for a neurological condition, they may perform additional tests to identify the cause.

The goal of treatment for PBA is to decrease the frequency and severity of episodes to improve quality of life. A doctor may recommend medications, such as tricyclic antidepressants or selective serotonin reuptake inhibitors, to achieve this.

Although these are drugs doctors also prescribe for depression, they can also improve the symptoms of other conditions. Scientists believe these drugs may help by altering neurotransmitter levels, but research on how they help is ongoing.

Another treatment option is the cough medication dextromethorphan, which inhibits the transmission of the neurotransmitter glutamine. Doctors may prescribe dextromethorphan together with quinidine.

Quinidine helps prevent the breakdown of dextromethorphan in the liver, and this leads to higher concentrations in the blood. In 2010, the Food and Drug Administration (FDA) approved a dextromethorphan-quinidine combination (Nuedexta) for PBA.

PBA is not a condition in its own right, so the outlook depends on what is causing it. For example, the outlook for people with a progressive neurological condition, such as ALS, will differ from those who have had a stroke.

That said, PBA alone can significantly affect a person’s work, social life, and mental health.

The American Stroke Association recommends people with PBA seek medical treatment. The organization also suggests the following steps if individuals experience PBA:

  • explaining PBA to loved ones and friends, so they will not feel surprised when the symptoms occur
  • taking slow, deep breaths and relaxing the muscles when symptoms happen
  • changing position during an episode or when an episode is coming
  • using distractions, such as thinking about something else or counting objects on a shelf, when an episode is imminent

Support groups for the specific conditions that can cause PBA can be a source of comfort and information. A person may wish to ask their doctor if a local support group is available for their condition.

The following national organizations can also direct someone to a local or online support group:

PBA is a neurological symptom that causes sudden, involuntary episodes of crying or laughing. The episodes range from mild to severe and occur as a result of neurological disorders such as MS.

PBA happens because of communication disruptions between the parts of the brain that control emotional expression. Because neurotransmitter levels can also be atypical, doctors may be able to reduce the frequency and severity of episodes with medications.

Coping mechanisms, such as deep breathing and using distractions, may also help when episodes are imminent. People who experience difficulties with the effects of PBA and neurological conditions may benefit from seeking emotional support from a healthcare professional or support group.