Obsessive Compulsive Disorder with Intellectual Disability: A Diagnostic and Therapeutic Challenge

Abstract

Obsessive compulsive disorder (OCD) are known to occur in patients with intellectual disability and at rates least proportional to the general population but often the developmental disabilities and lack of communication in these patients make it difficult to diagnose and assess the disorder and hence go undetected and untreated. Once diagnosed, treating OCD is another challenge faced by therapist in patients with intellectual disabilities. We report a case of intellectual disability with OCD highlighting the diagnostic and therapeutic challenges.

Case Report

A 36-year-old male presented to outpatient Department of Psychiatry in mental retardation clinic with complaints of an insidious onset illness characterized by repetitive acts of washing hands, excessive cleaning, bathing and refusing to touch anything when going out of house. When stopped from washing hands repeatedly, he becomes very irritated and gets aggressive and used to calms down when he washes his hands again. He had no significant past or family history of psychiatric illness and had no history of substance abuse.

Examination revealed normal vital functions. The general physical and systemic examination was normal. His complete blood count, liver function tests, kidney function tests, thyroid function tests, urinalysis, were within normal range. His blood sugar levels were deranged, fasting was 114 mg/dl and postprandial was 148 mg/dl.

A structured assessment was conducted and the intelligence quotient by Wechsler Adult Intelligence Scale-Performance Scale (Indian adaptation) [1], was found to be 46 (moderate mental retardation). Complete mental status examination was done and Yale-Brown Obsessive Compulsive Scale Symptom Checklist [2,3] was administered. He was found to be very anxious during interview and had obsessions of contamination and had compulsive cleaning and washing rituals.

Family members were given psychoeducation regarding the nature of illness and requirement of treatment. Patient was started on capsule Fluoxetine 20 mg daily. Patient was also sent for medicine consultation for deranged blood sugar levels. He was advised dietary modification and regular exercises. At 2 weeks there was minimal improvement but a new complaint of episodic sudden and severe aggressive behaviour came up. Patient’s irritability and aggressive behaviour was very prominent so sodium valproate 600 mg was added in divided doses. At 4 weeks, follow up when complaints of aggression resolved, Fluoxetine was increased to 40 mg and using differential positive reinforcement, exposure and response prevention was conducted. Patient was assessed at 2 weeks interval and it was seen that improvement started at 6 weeks of therapy and after around 10 weeks of therapy, patient was significantly improved. At 3 months follow up visit, significant improvement was reported in his daily functioning.

Discussion

Obsessive compulsive disorders (OCD) are known to occur in patients with intellectual disability and at rates least proportional to the general population but often the developmental disabilities and lack of communication in these patients makes it difficult to diagnose and assess the disorder and hence, goes undetected and untreated [4]. An OCD also occurs as behavioural phenotypes of specific disorders in persons with mental retardation as Down’s syndrome [5] and Prader-Willi syndrome [6].

OCD in patients with mental retardation presents with a diagnostic and therapeutic challenge. In patients with intellectual disabilities, first encountered symptoms are generally behavioural problems rather than anxiety. Compulsions occur in these patients, mostly in presence of cerebral dysfunction and in the absence of obvious "ego-dystonic" qualities that normally lead adults to report their behaviours’ as excessive or absurd. The assessment of observable behaviour has good reliability in diagnosing OCD in such patients and it has been documented in studies that emphasis should be on the behavioural, externally observable components of the disorder, rather than on inner conflicts and anxiety in diagnostic approach [7,8].

Once diagnosed, treating OCD is another challenge faced by therapist in patients with intellectual disabilities. Little is known about the pharmacological management of OCD in such patients and due to presence of brain dysfunction they are more prone to side effects of the neuroleptics. OCD in adults patients with mental retardation respond well to serotonergic agents [9–11]. For example, serotonergic antidepressants such as Fluoxetine, Sertraline, and Clomipramine were found useful in treating OCD [12–14] and therefore, can be used in conjunction with behavioural strategies. However, some authors have reported serious, adverse effects with the use of Clomipramine in this population [15]. Fluoxetine also have been found to aggravate, aggressive behaviour in persons with developmental disabilities [16]. Benzodiazepines also can be used to suppress anxiety but with caution as hostility, disinhibition, self injurious behaviour and aggression are reported as paradoxical reactions to benzodiazepines in this population, along with risk of abuse and dependence. The clinical consensus advises that benzodiazepines alone should only be used for a maximum of three weeks [17,18]. The goal should be to optimize pharmacological and behavioural intervention to minimize physical and emotional trauma to the patient and care givers while maximizing community integration [19].

This is a case of OCD with mental retardation. There is no doubt that diagnosing OCD in intellectually disabled individual is difficult because of presence of much repetitive behaviour, inability to express anxiety and ego dystonicity of the thoughts and behaviour. In this case also, OCD presented as behavioural problems in the form of irritability and aggression. The importance of externally observable behaviour has been seen in studies and it was found that single items describing observable behaviours’ had good reliability while inner resistance, subjective distress contributed little to the total score of the scale measuring severity [7]. Here also, prominent cleaning and washing rituals of the patient led the parents to report and helped in diagnosis. The repetitive behaviour has been assessed in patients of autism by Mc Dougle et al., and it is concluded that obsessive compulsive symptoms differ significantly from other repetitive thoughts and behaviour seen in this population [20].

Patients with intellectual disability also present with unique problems in therapy like difficulty in use of behaviour therapy, uncontrolled aggression, presence of multiple co morbid psychiatric and neurological disorders and it is aggravated by unpredictable side effects of psycho active medications [9]. Here in this case also, we observed increased irritability and aggression after starting treatment, which improved with addition of sodium valproate. Fluoxetine came out to be effective and took around 6 weeks for significant improvement along with the behavioural measures. Behavioural measures are important, especially when patient is prone to side effects of the drugs and it is to be considered wherever feasible, at least in mild to moderate mental retardation [19]. There are other case reports in the literature which also shows the difficulty faced in diagnosis and quotes the importance of behavioural measures such as differential reinforcement procedures in the treatment of OCD in mentally challenged [4,21].

Conclusion

This case report reflects the challenges faced in diagnosing OCD when associated with intellectual impairment and issues arising in the management of these patients. The importance of observing external behaviour and careful monitoring of unpredictable side effects during treatment and including behavioural measures wherever possible can help to a considerable extent in resolving these issues.

Financial or Other Competing Interests

None.