The trajectory of psychiatric disorders in young people with intellectual disabilities

Aust N Z J Psychiatry. 2000 Feb;34(1):80-4. doi: 10.1046/j.1440-1614.2000.00695.x.


Objective: This study addresses the question of how prevalence and patterns of psychiatric disorder change from childhood to adolescence in young people with intellectual disability (ID).

Method: A representative epidemiological sample of 582 young people with ID aged 4-19 years was surveyed in 1991-1992 and again in 1995-1996. The main measure of psychiatric disturbance was the developmental behaviour checklist (DBC), a 96 item parent/carer completed questionnaire with robust psychometric properties which provided an overall score, 6 subscale or syndrome measures of psychiatric disturbance and determined caseness.

Results: The findings confirmed that about 40% of young people with ID had psychiatric disorders which persisted over 4 years. Clinically significant change in symptoms with either deterioration or improvement occurred in around 14% of the sample.

Conclusion: Psychiatric disorder is 3-4 times more prevalent in young people with ID than in the general population. Less than 10% of these young people receive specialist services for a problem which is numerically as large as schizophrenia.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Australia / epidemiology
  • Child
  • Child, Preschool
  • Cohort Studies
  • Comorbidity
  • Cross-Sectional Studies
  • Female
  • Follow-Up Studies
  • Humans
  • Intellectual Disability / epidemiology*
  • Male
  • Mental Disorders / diagnosis
  • Mental Disorders / epidemiology*