Pseudobulbar affect (PBA) is treatable with both medication and behavioral strategies. The condition causes sudden, uncontrollable episodes of laughing or crying that don’t match how you actually feel, and it occurs in people with neurological conditions like stroke, traumatic brain injury (TBI), multiple sclerosis (MS), and ALS. One FDA-approved medication exists specifically for PBA, and several older antidepressants are used off-label at low doses to reduce episode frequency and intensity.
What PBA Is and Why It Happens
PBA is not a mood disorder. The episodes are involuntary, caused by damage to the brain pathways that regulate emotional expression. A person with PBA might burst into tears during a neutral conversation or laugh uncontrollably at something that isn’t funny. The emotion on the outside doesn’t reflect what’s happening on the inside, which is what distinguishes PBA from depression or other mood conditions.
PBA shows up across a range of neurological conditions. In one large study of 590 people with traumatic brain injury, roughly 16% had significant PBA symptoms using a strict screening threshold, while broader screening criteria flagged more than half the group. Similar rates appear in people with MS, ALS, stroke, and other conditions that affect the brain’s motor and emotional circuits. Despite being common, PBA is frequently misdiagnosed as depression or a psychiatric condition, which delays appropriate treatment.
The FDA-Approved Medication for PBA
The only medication specifically approved for PBA is a combination of dextromethorphan and quinidine, sold under the brand name Nuedexta. Dextromethorphan is the active ingredient. It works on receptors involved in glutamate signaling and emotional regulation in the brain. The problem is that the body breaks down dextromethorphan very quickly, so on its own it doesn’t stay in the bloodstream long enough to be useful. That’s where quinidine comes in: it slows down the liver enzyme responsible for clearing dextromethorphan, allowing therapeutic levels to build up.
Treatment starts with one capsule daily for the first seven days. After that first week, the dose increases to one capsule every 12 hours. This gradual ramp-up helps your body adjust. Because quinidine can affect heart rhythm at higher doses, the amount used in this combination is kept low, well below the doses historically used for heart conditions. Still, people with certain heart rhythm abnormalities or those taking medications that also affect heart rhythm need to discuss this carefully with their prescriber.
Common side effects are generally mild and include dizziness, diarrhea, and nausea. Most people tolerate the medication well, and many notice a meaningful reduction in the number and severity of their episodes within the first few weeks of treatment.
Off-Label Antidepressants at Low Doses
Before Nuedexta was approved in 2010, doctors treated PBA with antidepressants, and many still do. The key insight is that these medications work on PBA through their effect on serotonin availability in the brain pathways that control emotional expression, not because PBA is a form of depression. The doses used for PBA tend to be at the low end of what’s typically prescribed for depression.
Among SSRIs, the most commonly studied options for PBA include fluoxetine and citalopram at around 20 mg per day, and sertraline at around 50 mg per day. Tricyclic antidepressants like nortriptyline and amitriptyline are also used, typically at 20 to 100 mg per day, usually taken as a single dose at bedtime to reduce side effects like drowsiness. Tricyclics tend to come with more side effects overall (dry mouth, constipation, drowsiness) compared to SSRIs, which is why SSRIs are often tried first.
These off-label options can be especially useful for people who can’t take Nuedexta due to drug interactions or heart concerns, or for those whose insurance doesn’t cover the brand-name medication.
Behavioral Strategies During Episodes
Medication reduces the frequency and intensity of PBA episodes, but it rarely eliminates them entirely. Physical techniques can help you regain some control when an episode starts. Slow, deep breathing is the most effective in-the-moment strategy. Focus on long exhales, which activate the body’s calming response. Consciously relaxing your facial muscles and shoulders can also help shorten an episode. If you’re sitting, changing your body position, such as shifting your posture or standing up, can sometimes interrupt the cycle.
These techniques work best when practiced regularly outside of episodes so they become automatic. None of them will stop an episode instantly, but they can reduce its duration and help you feel less overwhelmed.
Talking to Others About PBA
One of the hardest parts of living with PBA is the social fallout. People around you may assume you’re deeply sad, emotionally unstable, or finding something funny when you’re not. This misunderstanding can lead to isolation and strained relationships.
The most important thing to communicate is that PBA episodes are involuntary. They are a neurological symptom, like a tremor or a muscle spasm, not a reflection of your inner emotional state. It helps to explain this during a calm moment rather than in the middle of an episode. Giving family members, friends, or coworkers a simple framework (“My brain injury sometimes causes sudden crying or laughing that I can’t control, and it doesn’t mean I’m upset or amused”) can reduce confusion and make social situations less stressful for everyone involved.
Getting Properly Diagnosed
PBA is a clinical diagnosis, meaning there’s no blood test or brain scan that confirms it. Doctors use screening tools like the Center for Neurologic Study-Lability Scale (CNS-LS), a short questionnaire that scores the frequency and severity of involuntary laughing and crying. A score of 13 or higher on this scale is the standard threshold for identifying PBA symptoms, though a stricter cutoff of 21 is sometimes used in research settings.
If you have a neurological condition and experience sudden, exaggerated emotional outbursts that feel disconnected from your actual mood, bringing this up with your neurologist is the first step. Many people live with PBA for years without knowing the episodes have a name or that effective treatment exists. Identifying the condition accurately matters because treating it as depression alone, without addressing the underlying emotional regulation problem, often produces incomplete results.