Akathisia Variants and Tardive Dyskinesia

To the Editor.—  The article by Barnes and Braude¹ and the comment by Stahl² are significant contributions to our understanding of the phenomenology of akathisia and the relationship between that disorder and tardive dyskinesia. In addressing the question "Is akathisia a movement disorder or a mental disorder?" Stahl suggests that the answer is both. We agree. However, this does not address the critical question of whether the movement-disorder component of akathisia is of a voluntary or involuntary nature. Viewing akathisia as a disorder of voluntary movement allows for an answer to Stahl's subsequent question of whether an examiner can distinguish abnormal dyskinetic movement from abnormal restless movements of akathisia. Thus, we have suggested that akathisia and tardive dyskinesia can be distinguished by discerning both the extent of subjective distress and the voluntary nature of the movements.³ By most definitions, patients with akathisia experience subjectively distressing inner restlessness.