The Use of Drugs for the Treatment of Behaviour Disorders in Adults who have Learning [Intellectual] Disabilities

Shoumitro Deb

• Management of behaviour disorders
• Evidence based practice
• Treating mental illness with medication
• Treating behaviour disorder with medication
• Limitations in the evidence base
• Treating ADHD and Autistic spectrum disorders (ASD) with medication
• Scope for drug withdrawal
  

Although the rate of functional psychiatric illness such as schizophrenia and affective disorders(Deb et al, 2001a) seems similar in adults who have intellectual disability to that in the general population, the rate of behaviour disorder is quite high (Deb et al, 2001b). The rate of psychosis is significantly higher among adults with intellectual disability compared with the general population, as are other psychiatric diagnoses such as autistic spectrum disorders and Attention Deficit Hyperactivity Disorders. Therefore, the overall rate of psychopathology among adults who have intellectual disability seems much higher compared with that in the general population (Deb et al, 2001c), as is the rate of epilepsy (Deb, 2000). Consequently, psychotropic medication is used more frequently in adults with intellectual disability, with between 20 and 45% of overall being prescribed psychotropic medication, of which 14-30% are to control behaviour disorders (Deb and Fraser, 1994). Clarke et al (1990) had previously found that 36% of adults with intellectual disability who did not have a diagnosis of mental illness were receiving psychotropic medication. Whereas the use of psychotropics in the treatment of mental illness is justified, their use in the management of behaviour disorders in people with intellectual disability in the absence of a diagnosable psychiatric illness remains controversial (see review by Reiss and Aman 1998; Santosh & Baird 1999; Deb & Weston, 2000; Aman et al, 2000).

Management of behaviour disorders
At the outset it is important to assess carefully the possible cause(s) of behaviour disorders. A person with intellectual disability who has toothache or gastro oesophageal reflux disorder (both are very common) and is unable to communicate this to her/ his carer may behave in an aggressive manner out of frustration and persistent pain. It is therefore important to assess the individual's physical state carefully and provide necessary symptomatic treatment. This might help to improve the associated behaviour disorders. Certain psychiatric syndromes such as psychoses and depression could manifest as behaviour disorders. Psychological factors such as stress and learned dysfunctional coping strategies could predispose and precipitate behaviour disorders. Behaviour therapy and psychological therapies such as Cognitive Behaviour Therapy may be useful in the management of such behaviour disorders. Certain social factors such as under or over stimulation within the immediate environment, physical and psychological abuse, life events and lack of social support may also predispose people with an intellectual disability to behaviour disorders. In many cases, addressing these social environmental issues may be all that is needed to improve behaviour disorders. The lack of careful assessment of these factors may lead to unnecessary prescribing of drugs.

Drug treatment is only one of many strategies that could be employed to manage psychopathology, and behaviour disorders in people who have intellectual disability. Treatment should be provided within the context of a carefully drawn individualised care programme after proper discussion with the person with intellectual disability, their carers, and other professionals involved in the care of the person. The overall aim of the treatment should not only be symptom control but to provide a better quality of life for an individual with intellectual disability and his/her carers.

Evidence based practice
The treatment also has to be based on the available evidence of effectiveness of a particular treatment. Clinicians in the UK are increasingly asked to abide by the National Institute for Clinical Excellence (NICE) guidelines (www.nice.org.uk), which are based primarily on type I and II evidence. Type I evidence includes good systematic reviews and meta-analysis of studies which include at least one randomised controlled trial, whilst type II evidence includes randomised controlled trials. Type III evidence includes well designed interventional studies without randomisation, type lV evidence includes well designed observational studies, and type V evidence includes expert opinion, influential reports and studies.

Treating mental illness with medication
Indications of drugs for the treatment of psychiatric disorders such as psychoses (e.g., schizophrenia,), affective disorders (e.g., depressive or manic episodes), and anxiety related disorders (e.g., obsessive compulsive disorder, phobias.) should be the same among people with intellectual disability as they are for the general population.

Treating behaviour disorder with medication
Types of behaviour disorders among people with intellectual disability that usually need drug treatment include aggression towards others, aggression towards property and objects (destructiveness), aggression toward self (Self injurious behaviour; SIB), severe agitation/ hyperactivity, severe stereotyped behaviour, and severe temper tantrums including screaming. There are published reports on the use of many drugs in the treatment of behaviour disorder among people who have learning disability. These drugs include antipsychotics, antidepressants, antiepileptics, mood stabilisers, psychostimulants, beta-blockers, opioid antagonists, and anti anxiety drugs

Among typical antipsychotics, chlorpromazine and haloperidol are the most widely used drugs for the management of behaviour disorders in adults with learning disability. The use of thioridazine is now severely restricted in the UK because of its potential cardio-toxicity. Most studies have reported improvement of the target behaviour following the treatment with atypical antipsychotics including clozapine, risperidone, olanzapine, amisulpride and quetiapine.

Among antidepressants, most studies have reported the use of clomipramine and Selective Serotonine Reuptake Inhibitors (SSRIs) in the management of behaviour disorders among adults with intellectual disability. As these drugs are known to improve symptoms of depression, anxiety and obsessive behaviour, it is possible that the improvement in behaviour disorders was in fact the reflection of improvement in the above symptoms.

There are reports of studies that have used mood stabilisers e.g., lithium, carbamazepine and sodium valproate for the treatment of behaviour disorders in people who have intellectual disability. Almost all studies showed improvement in behaviour following the lithium treatment. 88% of patients treated with valproate showed improvement in aggression and self-injurious behaviour. There is a complex relationship between epilepsy and behaviour disorders in some people who have intellectual disability (Deb & Joyce, 1999). It is possible, therefore, that sodium valproate may be treating the underlying epileptic activity while showing improvement in behaviour disorder.

Studies have shown that benzodiazepines, buspirone and beta-blockers improve behaviour disorders in people with intellectual disability. These drugs also have an anti-anxiety effect. Anxiety could be a precipitating factor for behaviour disorders in people with intellectual disability. The long-term use of benzodiazepines is contraindicated because of the problems with tolerance, possible effects on cognition and symptoms associated with withdrawal. After the initial enthusiasm with buspirone, recent studies have shown it has a slow onset of action and lower potency. Meanwhile, high dose beta-blockers can cause cardiac problems.

Some researchers have hypothesised that self-injurious behaviour is sustained by the release of internal opioids in the body. This consequently produces a feeling of pleasure, which tends to perpetuate the behaviour. Therefore, treatment with anti-opioid drugs such as naloxene and naltrexone has been proposed for the treatment of self-injurious behaviour in people with intellectual disability. However, to date the efficacy of naloxene and naltrexone has not been unequivocally proven in the management of self-injurious behaviour in people with intellectual disability. Trials with a lower dose of naltrexone have shown better results. Psychostimulants such as methylphenidate and dextamphetamine have been successfully used in the treatment of Attention Deficit Hyperactivity Disorder (ADHD) in children. Some studies have shown success with the use of these drugs in the treatment of behaviour disorders in people with intellectual disability. As many adults with intellectual disability show symptoms of ADHD, it is possible that psychostimulants show improvement in behaviour disorders by treating the underlying ADHD symptoms. The long-term effects of using psychostimulants have not been properly studied yet.

Clonidine is indicated for the treatment of 'Tic disorder' and 'Tourette's syndrome'. There are studies using clonidine in the treatment of behaviour disorders in people with intellectual disability. Both 'Tic disorder' and 'Tourette's syndrome' are known to be associated with intellectual disability and behaviour disorders. Vitamins, minerals and dietary treatments (particularly in patients with Phenylketonuria) have also been used with some success in the treatment of behaviour disorders in people with intellectual disability.

Limitations in the evidence base
Many studies have shown the effectiveness of many drugs in the treatment of behaviour disorders in adults with intellectual disability. However, we have to be cautious in the interpretation of data presented in these studies. Most of these studies are case reports that included a small number of cases. It is well known that studies with positive findings tend to find their way to publication more easily than studies that show negative findings, therefore creating a reporting bias. The number of RCTs is small, and have often used only small sample sizes, and therefore they provide insufficient statistical power to draw firm conclusions. The outcome measures used in these studies are often not appropriate or validated, and the method of selection of control and the experimental group is not always clear or appropriate. Also, outcome data are often not presented in an appropriate manner (e.g., most studies do not quote 'number needed to treat'). Most studies also do not distinguish symptoms of psychiatric illness from those of behaviour disorders.

A systematic review carried out by Brylewski and Duggan (1999) for the Cochrane Review group highlighted most of the methodological problems that I have listed above. By using strict criteria for inclusion of RCTs only, they found only three studies that provided either enough information or used appropriate methodology qualified for inclusion in their review. Their review found no evidence either way to suggest that drugs are either useful or not useful in the treatment of behaviour disorders in people with intellectual disability.

Treating ADHD and Autistic spectrum disorders (ASD) with medication
Psychostimulants such as methylphenidate in association with other methods of behaviour management are shown to be effective in the treatment of ADHD. They have been shown to be equally effective in the treatment of ADHD in children who have intellectual disability. Many reports have shown effectiveness of different drugs in the treatment of core symptoms and associated behaviour disorders in children with autistic spectrum disorders, but the quality of evidence is poor. Drawing on their clinical experience, Santosh & Baird (1999) have suggested the use of methylphenidate or clomipramine for hyperactivity; SSRIs for SIB; haloperidol, risperidone, buspirone or clonidine for irritability and aggression; and clonazepam, buspirone or beta-blockers for anxiety symptoms in children with autistic spectrum disorders. They also recommended the use of haloperidol, risperidone, sulpiride, clonidine, SSRIs, clomipramine or a combination of these drugs in the treatment of Tic/Tourette syndrome. They suggested the use of clonidine for hyperactivity or aggression or hyper arousal, and trycyclics or buspirone for children with combined symptoms of autism and ADHD.

Scope for drug withdrawal
Many people who have intellectual disability receive psychotropic drugs for many years without proper assessment of their treatment. Ahmed et al (2000) and Branford (1996) carried out important studies to assess which factors affect the withdrawal of long term use of these drugs. They successfully reduced antipsychotic medication, without the resurgence of behaviour disorders in 52% of 36 adults with learning disability, of whiom 33% completed the full withdrawal programme. They also found that factors such as staff perceptions, environmental factors, and staffing ratios influenced prescribing habits.

Clinicians prescribing drugs for people with intellectual disability should also be aware of issues relating to capacity, informed consent, advocacy, Mental Health legislation and relevant Government policies such as 'Valuing people' (www.doh.gov.uk) and 'Same as you'. Tables 1 and 2 summarise practice guidelines that have been proposed by an international consensus group (Reiss & Aman, 1988). The Department of Psychiatry at the University of Birmingham is developing a practice guideline for the use of drugs in the treatment of behaviour disorders in adults who have an Intellectual Disability (DATABID Project) (www.bham.ac.uk/psychiatry). This project is funded by the Community Fund and managed by MENCAP and is developed in association with the Learning Disability Faculty and the College Research Unit (CRU) of the Royal College of Psychiatrists.

References
Ahmed Z, Fraser W, Kerr M P et al. Reducing antipsychotic medication in people with a learning disability. British Journal of Psychiatry 2000; 178: 42-46.

Aman M G, Alvarez N, Benefield W et al. Expert consensus guidelines for the treatment of psychiatric and behavioral problems in mental retardation. American Journal on Mental Retardation 2000; 105: (3) 159-228.

Branford D. Factors associated with the successful or unsuccessful withdrawal of antipsychotic drug therapy prescribed for people with learning disabilities. Journal of Intellectual Disability Research 1996; 40: 322-329.

Brylewski J., Duggan L. Antipsychotic medication for challenging behaviour in people with intellectual disability: a systematic review of randomised controlled trials. Journal of Intellectual Disability Research 1999; 43: 360-371.

Clarke D J, Kelley S, Thinn K & Corbett J A. Psychotropic drugs and mental retardation: I. Disabilities and the prescription of drugs for behaviour and for epilepsy in three residential settings. Journal of Mental Deficiency Research 1990; 34: 385-395.

Deb S. Epidemiology and treatment of epilepsy in patients who are mentally retarded. CNS Drugs 2000; 13 (2): 117-128.

Deb S., Fraser W. The use of psychotropic medication in people with learning disability: towards rational prescribing. Human Psychopharmacology 1994; 9: 259-272.

Deb S. Psychotropic Medication for Behaviour Disorders Associated with Learning Disabilities.
Psychiatry 2003; Vol 2:9: 66-68.

Deb S., Joyce J. Psychiatric illness and behavioural problems in adults with learning disability and epilepsy. Behavioural Neurology 1999; 11: 125-129.
Deb S, Thomas M & Bright C. Mental disorder in adults with intellectual disability. I: Prevalence of functional psychiatric illness among a community-based population aged between 16 and 64 years. Journal of Intellectual Disability Research 2001a; 45 (6): 495-505.

Deb S, Thomas M & Bright C. Mental disorder in adults with intellectual disability. 2: the rate of behaviour disorders among a community-based population aged 16 and 64 years. Journal of Intellectual Disability Research 2001b; 45 (6): 506-514.

Deb S, Matthews T, Holt G and Bouras N. (eds.) Practice guidelines for the assessment and diagnosis of mental health problems in adults who have intellectual disability. European Association for Mental Health in Mental Retardation (EAMHMR). 2001c; Pavilion Press, London (www.estiacentre.org).

Deb S., Weston S N. Psychiatric illness and mental retardation. Current Opinion in Psychiatry, 2000; 13: 497-505.

Reiss S., Aman M G. The international consensus handbook: Psychotropic medications and developmental disabilities. American Association on Mental Retardation, 1998; Washington DC, USA.

Santosh P. J., Baird G. Psychopharmacology in children and adults with intellectual disability. Lancet 1999; 354: 231-240.

This article was first published on the site in 2004.

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