Glossary of psychiatry occurs within 2–3 months. Brain fag syndrome is an example of a culture-bound syndrome. "Brain fag" was once a common term for mental exhaustion. Today, the syndrome describes students (predominantly males, particularly in West Africa) experiencing symptoms including somatic, sleep-related and cognitive complaints, head and neck pains, difficulty in concentrating and retaining information, and eye pain. Brain fog is another term for #Clouding of consciousness. Bruxism refers to teeth grinding behaviour that is usually seen in children. In Capgras syndrome, the patient feels that a person familiar to him, usually a family member has been replaced by an imposter. This
Bruxism in research declined from over 60% of publications in the period 1966–86 to about 10% in the period 1997–2007. In the 1960s, a periodontist named Sigurd Peder Ramfjord championed the theory that occlusal factors were responsible for bruxism. Generations of dentists were educated by this ideology in the prominent textbook on occlusion of the time, however therapy centered around removal of occlusal interference remained unsatisfactory. The belief among dentists that occlusion and bruxism are strongly related is still widespread, however the majority of researchers now disfavor malocclusion as the main etiologic factor in favor of a more multifactorial, biopsychosocial model