Akathisia in adults with severe and profound intellectual disability: A psychometric study of the MEDS and ARMS

Background This study assessed the psychometrics of two measures - the Matson Evaluation of Drug Side-effects (MEDS) and the Akathisia Ratings of Movement Scale (ARMS) - and examined the symptom profile of akathisia in a sample of people with intellectual disability (ID). Method Sixty-six participants formed three groups of 22 individuals, matched on age, race, sex, and level of ID. The sample comprised Group 1: individuals with no antipsychotic drug use and no diagnosis of akathisia (control group); Group 2: individuals taking antipsychotics and with no diagnosis of akathisia (no akathisia group); and Group 3: individuals taking antipsychotics and with a diagnosis of akathisia (akathisia group). Results Both measures indicated the presence of akathisia in those individuals with a diagnosis of akathisia, while the two groups without a diagnosis of akathisia did not qualify for a diagnosis of akathisia on either scale. Interestingly, item analysis of the MEDS and ARMS tended to identify different symptoms of akathisia and were moderately correlated. Conclusions The data appear to suggest that both measures have merit, that they are complementary, and that they should be used together when assessing akathisia in individuals with ID.