Functional neurological disorder (FND), classified under the somatic symptoms and related disorders in the Diagnostic and Statistical Manual of Mental Disorders (DSM5) , is characterised by involuntary neurological symptoms which are not explained by a known neurological or other medical condition, or by another mental health disorder. Previously in DSM4, FND was a diagnosis of exclusion, but the description changed in DSM5, which specifies FND as a ‘rule-in’ diagnosis.
