Chrissoula Stavrakaki, M.D., Ph.D., FRCPC
Child & Family Psychiatric Unit
Ottawa General Hospital, Ottawa, Canada
G. Mintsioulis, M.D.
1995 National Association for Dual Diagnosis II Conference
  Reprinted with the permission of Robert J. Fletcher, DSW, ACSW
NADD Founder and Executive Director
132 Fair Street
Kingston, NY 12401
(914) 331-4336

Obsessive Compulsive Disorders (OCD) are currently considered to be present in approximately 3.5% of the mentally retarded population. OCD is referred to as recurrent, disturbing thoughts and repetitive stereotyped behaviour that the person feels driven to perform but recognizes as irrational and excessive2. In contradistinction, stereotypy, refers to behaviours, that persons engage in, that are pleasurable, such as rocking, banging, flipping and swinging of objects. Other behaviours that are not considered as OCD include; verbal perseveration, humming, demanding attention, stealing, pacing and excessive masturbation.
Obsessive Compulsive Disorder (OCD) in the general population appears to be relatively more common than earlier thought of. Recently, epidemiologic studies suggest that as many as 2 to 3% of all Americans may suffer from it at some point during their life times3. These rates are more than 20 times higher than previous prevalence estimates7 and indicate that OCD is more common than schizophrenia or panic disorder. Children develop OCD in the same form as seen in adults. Symptoms include: washing (85%), repeating, checking, touching, arranging, counting and hoarding (15%).
The co-existence of OCD and Down's syndrome has been thought to be very rare. The paucity of relevant reports in the literature stands testimony to this. On reviewing the literature, only one reference was found to describe two cases of OCD in individuals with Down's syndrome4. This report concludes that it is, still, unclear whether or not Down's are more vulnerable to OCD than the other categories.
In this study, five individuals with DS were found to be suffering from OCD and were treated successfully with serotonin reuptake inhibitors as single therapy or enhanced by other related drugs. Another five mentally retarded individuals (non-Down's) with OCD were matched with respect to age, sex, life events, symptoms and degree of retardation. The following case reports outline each of the five Down's with OCD and their clinical characteristics.

Case report #l

M.M., a 28 year old female Down's (regular Trisomy), had 12 month history of behaviour change with abrupt onset that followed a traumatic event (rape). The initial symptoms included insomnia, loss of appetite with considerable weight loss and anhedonia. Symptoms changed to agitation with obsessive intrusive thoughts such as excessive preoccupation with news, music and media presentations of the popular group the New Kids on the Block. Premorbid personality revealed perfectionistic behaviour, need for sameness, since 14 years of age. Other compulsive behaviour included checking, rechecking and hand washing.

Case report #2

J.P., 32 year old male Downs (regular Trisomy), had a 24 month history of behaviour change of abrupt onset following a move from the parental home to semi-independent living. Initial symptoms included inability to concentrate and cope with work, loss of weight, bulimic episodes, disturbance of sleep and excessive and inappropriate fondling of others. Premorbid personality, revealed excessive cleanliness, fear of contracting diseases since 16 years of age. Other Obsessive Compulsive behaviours included counting, recounting and washing.

Case report #3

P.S., 37 year old male Down's (regular Trisomy), had a 3 year history of behaviour change with abrupt onset following families move from the US to Canada. Initial symptoms included difficult behaviour at work, withdrawal, regression in all social areas, loss of sleep and appetite with subsequent loss of weight, aphonia, difficulty crossing lines, walking close to edge of road and building. Premorbid personality revealed resistance to change, orderliness, and meticulousness since 14 years of age. Other obsessive behaviours included whispering, frequent visits to washrooms and checking.

Case report #4

D.M., 32 year old male Down's (regular Trisomy), had a 14 month history of behaviour change with abrupt onset following a serious motor vehicle accident while he was being transported to a football game. Initial symptoms included secondary day enuresis, inability to cope with work, regression in all social areas, refusal to use any means of transportation, panic attacks with wetting following demands to change activity, preoccupation with bodily functions and thumb sucking. Premorbid personality revealed orderliness, aggression, need to keep room same, crossing over lines since 10 years of age. Other obsessive behaviours included checking, washing and wetting.

Case report #5

D.M., 25 year old female Down's (regular Trisomy), had a three year history following move from parental home to semi independent living. Initial symptoms included withdrawal, whispering, inability to concentrate at work, loss of sleep and appetite with bulimic episodes, rearranging of furniture and clothing to a specific order with aggression if routines interrupted. Premorbid personality revealed need to sameness, orderliness, excessive preoccupation with clothing and order in her own room. Other obsessive behaviours included licking of hands, wearing clothes inside out, constant arranging of furniture and washing.

All cases were treated initially with behavioral interventions offered by behavioral psychologists within community settings with little or no success. All individuals were seen in a psychiatric clinic at a General hospital. In all cases a full psychiatric evaluation was carried out including interview assessment by two psychiatrists in a blind form. Diagnosis of Obsessive compulsive disorder was made based on DSM-III-R criteria with interrater reliability of 96%.
All cases were treated with Clomipramine at a dose range of 30-75 mg enhanced in three cases by Buspirone 10 mg 3 times daily. 40-60% range of improvement was found to be present within 8 weeks of commencement of treatment. Higher doses of Clomipramine when tried proved to be very difficult for the individuals concerned due to excessive side effects. Most commonly occurred side effects, in order of severity of subjective disturbance, were: constipation, dry mouth, dizziness, blurred vision and inability to urinate. Lowering of the dose of Clomipramine reduced the side effects to a tolerable level and, in some instances, side effects completely ceased.
Five non-Down's mentally retarded patients with OCD were, then, compared to the afore mentioned group. These individuals were matched as much as possible with the Down's syndrome group, for number, age, sex, life events, symptoms and degree of retardation. Table 1 shows the two groups with respect to number, age and sex.

Table 1
  Down's  Non-Down's
Female/Male 2/3  2/3 
Age/Years Mean 30 
Range 24-30 
Mean 30 
Range 22-40 

Charts 1-3 show the clinical characteristics of Down's syndrome patients with OCD as compared to other mentally retarded individuals with OCD. Chart 1 compares the life events in the two matched groups. It is noteworthy, that life events appear to be very significant in the Down's group and less so in the non-Down's.

Chart 1
Life Events
Chart 1

Chart 2 shows the comparison of the two groups with regards to symptom presentation. There were no significant differences found between the two groups.

Chart 2
Symptom Presentation of Down's vs Other
Chart 2

Chart 3 compares the degree of retardation between the two groups. No significant differences were found. The treatment regime used in the non-Down's mentally retarded patients with OCD seemed to be more relevant to the individual diagnosis and other related symptoms such as aggressivity, stereotypy, self injurious behaviour and hyperactivity. Drugs such as Fluvoxamine and Sertraline were used in patients with self-injurious behaviour and aggressivity enhanced with Buspirone resulting in 50-65% reduction of symptoms. Hyperactivity and stereotypy appeared to have responded favourably to agents such as Clonidine and Orap.

Chart 3
Degree of Mental Retardation
Chart 3

Chart 4 shows the various drugs used either alone or enhanced as compared to chief complaint/diagnosis mentally retarded patients with OCD (non-Down's).

Chart 4
Drugs Used in Treatment of Non-Down's
Chart 4

In contrast, as mentioned during the case discussions, Down's patient's with OCD were successfully treated (symptom improvement in 4 out of 5 cases) with low to medium range doses of Chlomipramine enhanced by Buspirone (Chart 5).

Chart 5
Treatment of Down's with OCD
Chart 5

In summary, the results of this study seem to indicate that Down's syndrome individuals are more vulnerable to develop OCD following serious traumatic events with a depressive illness of short duration (6-8 months) preceding the onset of OCD symptomatology. Deficits in serotonin metabolism specific in Down's might be of etiological significance1,5,6. OCD in Down's appears to be responding favourably to treatment with serotonin reuptake inhibitors, more specifically Clomipramine in monotherapy or enhanced by other drugs such as Buspirone. Further enquiry is of importance in better understanding of the mechanisms operative in the development of OCD in Down's in order to prevent and or ameliorate such symptoms and, in turn, enhance the quality of life of these individuals.


  1. Brugge KL, Nichols SL, Salmon DP, et al: Cognitive impairment in adults with Down's syndrome: Similarities to early cognitive changes in Alzheimer's disease. Neurol 44: 232-238, 1994.
  2. Diagnostic and Statistical Manual of Mental Disorders, 3rd Ed., Revised. Washington, American Psychiatric Association, 1987.
  3. Kamo, M., Golding, J. M. Sorenson, S.B., et al: The Epidemiology of Obsessive Compulsive Disorder in Five US Communities. Arch Gen Psychiatry, 45: 1094-1099, 1988.
  4. O'Dwyer J, Holmes J, Collacott RA: Two cases of obsessive-compulsive disorder in individuals with Down's syndrome. J Nerv Ment Dis 180(9):603-4, 1992.
  5. Soyninen H, Partanen J, Jousmaki V, et al: Age-related cognitive decline and electroencephalogram slowing in Down's syndrome as a model of Alzheimer's disease. Neurosci Vol 53, 1:57-63, 1993.
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  7. Woodruff R, Pitts FN Jr: Monozygotic twins with obsessional illness. Am J Psychiatry 120:1075-1080, 1964.