Abstract
Interruption of ongoing treatment with benzodiazepines, antidepressants, antipsychotics and mood stabilisers including lithium can be followed by clinically significant withdrawal reactions within hours or days, as well as later increases in relapses or recurrences of the illness being treated. Such observations support the view that stopping treatment is not equivalent to being untreated. With lithium, antipsychotics and antidepressants, there is consistent evidence that abrupt or rapid discontinuation is followed by earlier clinical worsening than with more gradual removal of treatment. Moreover, treatment discontinuation can complicate interpretation of responses to changes in treatment, including in clinical practice and in experimental treatment trials. Notably, terminating preceding treatments can lead to both discontinuation and carry-over effects that can have an impact on the interpretation of observed outcomes.