Functional movement disorders are the most challenging movement disorders to diagnose and treat. Phenomenology and disease course are variable. This group of disorders includes tremor, dystonia, myoclonus, parkinsonism, speech and gait disturbances, and other movement disorders that are incongruent with patterns of pathophysiologic (organic) disease.

Patients with bodily distress, hypochondriasis and chronic pain experience symptoms that impair their functioning and cause them significant degrees of discomfort. They also represent a significant public health challenge. Problems in classification/nosology continue to bedevil this area, and these difficulties – along with the use of the language of psychiatric classification, which most patients find unacceptable – continue to led to the DSM/ICD terms being little used in day-to-day clinical practice, including liaison psychiatry. Biological, psychological and social factors are relevant to both the aetiology and the maintenance of these syndromes, as well as to their treatment. In recent years, a variety of effective biological and psychosocial approaches to treatment have been developed, and these patients can now be considered as a group for whom medical and psychological approaches should be offered.