Psychiatric Disorders in Persons with Down Syndrome: A Review of Studies

Glenn Vatter
3124 Henneberry Road
Jamesville, NY 13078-9640
(315) 677-3844
  Reprinted with the permission of the author
© 1998 Glenn Vatter
All rights reserved

     There has often been some speculation as to whether persons with Down syndrome are susceptible to psychiatric disorders. Because of their affable nature and mental retardation it has been thought that that they do not suffer such disorders as much as the general population.
     While researching occurrence rates of autism in the Down syndrome population, I came across some studies concerning psychiatric and behavior disorders amongst Downs persons and others with mental retardation. I will present here some charts taken from those studies. More complete data may be obtained by reviewing the studies.
     In general, the studies showed that people with Down syndrome appear to be susceptible to a spectrum of mental disorders different to that of other mentally retarded persons. Overall, those with Down syndrome appear to be less vulnerable to mental disorders than those with other mental handicaps. They are more vulnerable to Alzheimer's Dementia and depressive disorders, but are in some ways protected against the development of schizophrenia, paranoid states, and conduct and personality disorders. Autistic traits appear to be equally common in those with Down syndrome as in those without. (Collacott et. al., 1992)
     The studies reviewed are as follows: Condensations are as follows:

Collacott, et. al. (1992)
     Study was done by reviewing case records of persons with Down syndrome in Leicestershire, England. Case records of the Down syndrome persons were compared with those of individuals with mental retardation but without Down syndrome. Psychiatric diagnoses were determined from the information available in these records. The range of ages of the individuals was 16 - 78 years with a mean of 36 years. (Since the study was published in 1992, the records would have been from periods going back into the 1930's or earlier?) The Psychiatric findings from the records were retroactively classified in accordance with ICD-9 criteria (World Health Organization 1978). These retrospective diagnosis included:

n = 371 persons with DS
No Disorders   275     (74.1%)
Depression 42 (11.3%)
Manic-depressive psychosis 2 (0.5%)
Presenile Dementia 16 (4.3%)
Autism2 8 (2.2%)
Conduct Disorders 23 (6.2%)
Personality Disorder 0  
Neurotic Disorders excluding Depression   1 (0.3%)
Schizophrenic/paranoid states 6 (1.6%)
Other diagnosis1 4 (1.1%)

Gath, Ann & Gumley, Dianne (1986)
     Study was aimed at determining occurrences of behavior problems in children with Down syndrome. Data were collected during the period of 1979-1982. Interviews were conducted with the parents. Parents were asked to fill out the Rutter A2 behavioral scale. Teachers were asked to fill out the Rutter A2 scale, the Adaptive Behavior scale, and the Additional Behavior checklist.
     The resulting ICD-9 diagnostic results showed 74 children with Down syndrome with behavior disorders from a population of 193. The breakdown is as follows:

No Disorders   119    (77.2%)
Infantile autism2 2 (1%)
Psychosis with origin specific to childhood 17 (8.8%)
Unsocialised disturbance of conduct 21 (10.8%)
Mixed disturbance of conduct and emotions 9 (4.7%)
Disturbance of emotions specific to childhood and adolescence - other mixed 6 (3.1%)
Hyperkinetic syndrome of childhood - with developmental delay 4 (2.1%)
Hyperkinetik conduct disorder 14 (7.2%)
Undiagnosed 1
Total Diagnoses (44 boys, 30 girls)1 74

Beverly A. Myers & Siegfried M. Pueschel (1991)
     Study involved 425 persons with Down syndrome as outpatients of Childhood Development Center at Rhode Island Hospital, plus 72 persons with Down syndrome from a nearby state school. Psychiatric diagnosis were made (from the medical records?) according to DSM-III-R criteria based upon psychiatric and psychological evaluations, multidisciplinary reports, and the descriptions of the patients' behavioral and emotional status. Two diagnosis in addition to the DSM-III-R included aggressive behavior (persistive assaultive behavior not fitting conduct or impulsive disorders) and self-injurious behavior. [This sounds like autism to me.] The results are as follows:

No Disorders 315     (74.1%)
Disruptive Disorders
  • Attention Deficit Disorder 21 (4.2%)
  • Conduct/oppositional Disorder 18 (3.6%)
  • Aggressive behavior 36 (7.2%)
Anxiety Disorders
  • Phobias 5 (1%)
  • Obsessive compulsive behavior    4 (0.8%)
  • Conversion Disorder 1 (0.6%)
Gastrointestinal Disorders
  • Eating problems 6 (1.2%)
  • Elimination difficulties 8 (1.6%)
Repetitive behaviors
  • Tourette syndrome 3 (0.6%)
  • Stereotypic behavior 14 (2.8%)
  • Self-injurious behavior 8 (1.6%)
Affective disorders
  • Major-depressive disorders 10 (2%)
  • Manic-depressive disorders 1 (0.2%)
  • Organic affective syndrome 1 (0.2%)
  • Dementias 6 (1.1%)
  • Paraphilias 3 (0.6%)
  • Schizophrenia 0  
  • Autism2 5 (1%)
Total1 110 (22.1%)

Gillberg, C., Persson, E., Gruffman, M., Themner, U. (1986)
     Group of 149 mentally retarded children were examined in Goteberg, Sweden in the spring of 1984. Psychiatric examinations were conducted by doctors trained (min 6 mo.) in child psychiatry. Children were 13 - 17 years of age.
     The following diagnosis were made:

     Of 83 children with mild mental retardation, 6 were Down syndrome. None of the children with Down syndrome showed psychiatric disorders.
     Of 66 children with severe mental retardation 16 were Down syndrome. Of these, 9 were found to have no psychiatric disorders. One was diagnosed with infantile autism and 2 with autistic-like characteristics (triad of social and language impairments).
     Of the total of 22 children with Down syndrome, then, 3 (13.6%) were found to have infantile autism or autistic-like characteristics.


  1. Numbers and percentages do not always add up because some persons were diagnosed with two disorders.
  2. In most cases, some of the diagnosis not called autism may actually be called autism. Autism occurs in about 5-10% of persons with Down syndrome. See "Diagnosis of Autism in Children With Down Syndrome" (1997), paper by Glenn Vatter.

  Revised: June 9, 1999.