Stereotypic Movement Disorder
A. Repetitive, seemingly driven, and apparently purposeless motor behavior (e.g., hand shaking or waving, body rocking, head banging, self-biting, hitting own body).
B. The repetitive motor behavior interferes with social, academic, or other activities and may result in self-injury.
C. Onset is in the early developmental period.
D. The repetitive motor behavior is not attributable to the physiological effects of a substance or neurological condition and is not better explained by another neurodevelopmental or mental disorder (e.g., trichotillomania [hair-pulling disorder], obsessive compulsive disorder).