Functional cognitive disorders: update on diagnostic status

Many patients referred to cognitive disorders clinics are not found to have evidence of any neurological disorder(s) to account for their symptoms. Many demonstrate incongruence between their subjective cognitive symptoms and preserved social and occupational functions. The term 'functional cognitive disorders' (FCD) has been used to denote this diagnostic category. This article aims to review the current state of knowledge regarding FCD. Studies of FCD are in their infancy, but available evidence suggests positive diagnosis may be made based on typical clinical profiles, including language discourse and simple clinical signs. Concurrent mood disorder and sleep disturbance are common, as well as other functional disorders. Pathogenesis is yet to be determined, but a disorder of metamemory has been suggested.