Stereotypic Movement Disorder

Criterion A

Repetitive, seemingly driven, and apparently purposeless motor behaviour (e.g. - hand shaking or waving, body rocking, head banging, self-biting, hitting own body).

Criterion B

The repetitive motor behaviour interferes with social, academic, or other activities and may result in self-injury.

Criterion C

Onset is in the early developmental period.

Criterion D

The repetitive motor behaviour 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, obsessive-compulsive disorder).


Specify if:

  • With self-injurious behaviour (or behaviour that would result in an injury if preventive measures were not used)
  • Without self-injurious behaviour
  • Associated with a known medical or genetic condition, neurodevelopmental disorder, or environmental factor (e.g., Lesch-Nyhan syndrome, intellectual disability, intrauterine alcohol exposure).

What's the difference between stereotypy and tics?

The onset of stereotypy is earlier, around 1 to 3 years of age. Tics, on the other hand, usually begin around age 7 or 8, and start caudally, beginning with behaviours like blinking and coughing. Tics can wax and wane, and can get worse before it ultimately gets better and resolves on its own. Tics will diminish with age as puberty progresses. Stereotypies do not change form, and are egosyntonic.