Overall, the trial showed a statistically significant benefit from taking a combination of dextromethorphan and quinidine, with both dosages being safe and well tolerated. For a secondary objective measuring a participants "perceived health status...measuring eight health concepts: vitality, physical functioning, bodily pain, general health perceptions, physical role-, emotional role-, social role functioning, and mental health," the higher dosage showed improvement, especially on measures of social functioning and mental health. Epidemiology
Prevalence estimates place the number of people with PBA between 1.5 and 2 million in the United States alone, which would be less than 1% of the U.S. population even at the high end of the estimate. Some argue that the number is probably higher and that clinicians underdiagnose PBA. However, the prevalence estimate of 2 million is based on an online survey. Self-selected computer-savvy patients in at-risk groups evaluated their own symptoms and submitted their self-diagnoses. No doctor or clinic confirmed the data. Motivation to participate could have been influenced by the presence of symptoms, which would have skewed the results. The actual prevalence could very well be quite a bit lower than estimated. History
The Expression of the Emotions in Man and Animals by Charles Darwin was published in 1872. In Chapter VI, "Special Expressions of Man: Suffering and Weeping", Darwin discusses cultural variations in the acceptability of weeping and the wide differences in individual responses to suffering.
The chapter contains the following sentence:

We must not, however, lay too much stress on the copious shedding of tears by the insane, as being due to the lack of all restraint; for certain brain-diseases, as hemiplegia, brain-wasting, and senile decay, have a special tendency to induce weeping. Terminology
Historically, there have been a variety of terms used for the disorder, including pseudobulbar affect, pathological laughter and crying, emotional lability, emotionalism, emotional dysregulation, or more recently, involuntary emotional expression disorder. The term pseudobulbar (pseudo- + bulbar) came from the idea that the symptoms seemed similar to those caused by a bulbar lesion (that is, a lesion in the medulla oblongata). Terms such as forced crying, involuntary crying, pathological emotionality, and emotional incontinence have also been used, although less frequently. In popular culture
Arthur Fleck, the central character of the 2019 film Joker, displays signs of pseudobulbar affect, which are said to be what Joaquin Phoenix used as inspiration for his characters signature laugh. In the 2019 movie Parasite, the character Ki-woo sustains head trauma, and although it is not clearly mentioned that hes affected by pseudobulbar affect, he mentions not being able to stop laughing when thinking about all the events that occur in the movie. In the medical television show House, season 7, episode 8 ("Small Sacrifices"), the character Ramon Silva, played by Kuno Becker displays pseudobulbar affect, with uncontrollable incongruent laughter, while having the Marburg variety of multiple sclerosis.