ASSESSMENT & MANAGEMENT

Medication in people withlearning disability andmental illnessGregory O’Brien

Iain McKinnon

AbstractPsychiatric medications are often used in the treatment of mental disorders

as well as for problem behaviours in people with learning disabilities.

However, there is little evidence directly relating to people with learning

disability, and most treatment decisions and experience of medication

are based on research in the general population. Good practice demands

that clinicians make every effort to ascertain whether the presenting

complaints are those of a diagnosable mental disorder and that there is

multidisciplinary support to ameliorate problem behaviours.

Keywords evidence-based practice; learning disability; mental disorders;

psychiatric medication

Introduction

The clinical management of people with learning disability

affected by mental illness often entails drug therapy. This is, of

course, only instigated as one part of the treatment programme,

in conjunction with the other key elements of the multimodal

plan. In the management of mental illness among people with

learning disability, the clinician is often required to address

aspects of physical and general health, rather than primarily

mental illness per se. However, this is not covered in the present

article, which concentrates on the use of psychopharmaceutical

agents.

Principles of drug prescribing for mental illness in learning

disability

Establish psychiatric diagnosis

Prescribing of medication for mental illness in this population

should be diagnosis driven, but this is by no means straightfor-

ward. The diagnosis of mental illness among people with

Gregory O’Brien MA FRCPsych FRCPCH MD is Professor of Developmental

Psychiatry at the University of Northumbria and Northgate Hospital,

Morpeth, UK. His research interests include outcome studies in learning

disability and the biological basis of behaviour disorder in develop-

mental disability. Conflicts of interest: none declared.

Iain McKinnon BA MBBS MRCPsych is a Specialty Registrar (ST4) in

Developmental Psychiatry at Northgate Hospital, Morpeth, UK, and an

Academic Clinical Fellow in Forensic Psychiatry at Newcastle University,

UK. His research interests include the identification of individuals with

health morbidity within the Criminal Justice System. Conflicts of

interest: none declared.

PSYCHIATRY 8:10 413

learning disability is a complex specialist matter, reviewed on

pages 376e81 (in this issue). As emphasized throughout these

articles on learning disability, many of the behavioural constel-

lations encountered in clinical practice among people with

learning disability do not constitute diagnosable mental illness.

However, diagnosable psychiatric disorder is common among

people with learning disability, and, where possible, the diag-

nosis should be the starting point in the use of pharmacological

approaches to treatment.

Establish cause and severity of learning disability

The severity, or degree, of learning disability has major impli-

cations for the use of drug therapy. At a basic level, there is the

pathoplastic effect of the severity, or degree, of learning disability

on psychiatric disorder. This effect is mediated through the

individual’s cognitive level because so much of the expression of

psychopathology is determined by overall intelligence and

cognition. The more severely learning disabled the individual,

the greater will be the divergence from more familiar presenta-

tions of any psychiatric disorders e and this effect operates in

addition to the proneness of a particular condition to have its

own, unique, behavioural phenotype. Standardized clinical

assessment of the severity of learning disability and, where

possible, establishment of the underlying cause are both

prerequisites to planning for drug treatment.

Heed the evidence base

All prescribing of medication must be informed by the available

evidence base, although the evidence base for use of psycho-

pharmacological agents in people with learning disability per se

is scant. This is principally because, for ethical reasons, few drug

trials can be carried out in a population that includes so many

people who are not capable of giving consent to such research,

and so the evidence base for the use of psychopharmaceutical

agents derives mainly from findings among the general pop-

ulation. The principal evidence base to be consulted and

followed in prescribing for mental illness in learning disability is

therefore the mainstream evidence base for prescribing for the

diagnosis in question. This is supplemented by drug treatment

studies that have been carried out among people with learning

disability. Many of these, notably one major recent multicentre

study, have highlighted the need for a cautious approach to

prescribing.1 Most studies that have focused on prescribing for

behaviour disorder rather than mental illness in learning

disability have found little evidence of clear benefit of drug

treatment for behaviour disorder in the absence of a psychiatric

diagnosis. Faced with this problem, a useful consensus document

has been developed based on the experience of UK clinicians in

this area.2

Take caution with dosage

Here, the rules are simple e start low, go slow. For all

psychopharmacological treatment of people with learning

disability, the starting dose should be lower than for other

patients; in most cases, half the usual dose to be recommended.

This is done in order to minimize unwanted side-effects,

particularly any sedation, movement problems, or central

nervous system side-effects, all of which are more common

among people with major developmental disabilities.3 For the

� 2009 Published by Elsevier Ltd.

The decision to maintain or withdraw drug treatment

C Should be made in partnership with the patient, family, and

ASSESSMENT & MANAGEMENT

same reason, incremental increases in dosage should be made

more slowly, with the result that attaining dose for maximal

effect is reached over twice the time-frame that applies in

mainstream practice.

carers

C Is dependent on the clinical response to treatment

Avoid polypharmacy C Is dependent on occurrence of side-effects

C Should follow a period of clinical recovery

C Is informed by the natural history of the condition being treated

Box 1

It is particularly important to minimize polypharmacy in the

management of mental illness among people with learning

disability. This is important because of the prominent problems

of side-effects in the index patient group, and also because of the

difficulties inherent in discerning the positive and negative

effects of individual drugs when given in combination e espe-

cially to people who may lack the ability to communicate their

experience of drug effects. Not infrequently in this area of prac-

tice, however, the clinician will be faced with requests to use

more and more medication, especially where there has been

some initial positive effect that has subsequently apparently

dissipated. In this common scenario, it is important to reappraise

the individual’s whole situation, rather than add additional

medication. In individuals in whom polypharmacy becomes

established, the clinician’s first duty is to take a thorough drug

history, from the individual as far as possible, and from key

carers including family members. This can serve to identify

issues such as the positive or negative impact of any medication

that has been used, and drug interactions can also be identified

and minimized in the future.

Consider formulation

For the most part, orthodox formulations, whether of oral or

parenteral medication, will apply. However, especially where

any compliance issues have arisen e and also where there are

physical factors interfering with, for example, swallowing e

it is occasionally necessary to explore less orthodox prepa-

rations or methods of administration. This may be something

as simple as rendering the treatment more pleasurable,

perhaps by attention to colour or taste. Any such consider-

ations may be best worked through in close collaboration

with a pharmacist.

Optimize compliance

More than elsewhere in psychiatric practice, much of this drug

therapy will be under supervision of carers and/or family. The

clinician must offer the relevant family/carers every possible

assistance and support in this endeavour, for their efforts will

be the main determinants of compliance. In turn, their efforts

will be all the more determined if they are fully informed of the

effects of the medication in question, including side-effects.

This can be quite a challenge, especially where unwanted

effects have been experienced from any previous medication

used. However, only a full and informed account of any likely

problems will be accepted now by most carers, parents, and

families.

Follow informed consent

In the treatment of children with learning disabilities, consent to

treatment is essentially the province of the parent/carer. Careful

close consideration of the emergence or non-emergence of the

capacity to consent to treatment in adulthood must be given,

under the respective legislation.4,5

PSYCHIATRY 8:10 414

Initiating drug treatment

The decision of whether to incorporate drug treatment into

a multimodal programme of management in clinical practice relies

on a clear understanding of the nature and circumstances of the

presenting problem. Behavioural problems that are brief, self-

limiting, a reflection of inter-current physical health problems, or

due some identifiable environmental or personal stressor in the

individual’s life do not merit psychotropic medication. However,

a decision to commence drug treatment may be sometimes taken

too late, on the basis that all other avenues should be explored first

of all. Where a diagnosable psychiatric disorder presents that has

clear treatment implications, such as depression, the decision to

adopt psychopharmacology may be taken more readily.

Maintaining and withdrawing drug treatment

The decisions to maintain and withdraw drug treatment should

be approached with the same care and caution as the decisions to

initiate drug treatment (Box 1). Duration of drug treatment will

depend on various factors, including compliance, habituation

and course of titration to maximal effect, response to treatment,

occurrence of side-effects, and the natural history of the disorder

being treated. The timescales of duration of treatment and

withdrawal regimens should be extended, in line with the time-

scales for initiation and titration. A

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FURTHER READING

Advocat CD, Mayville EA, Matson JL. Side effect profiles of atypical anti-

psychotics, typical antipsychotics, or no psychotropic medications in

persons with mental retardation. Res Dev Disabil 2000; 21: 75e84.

Ahmed Z. Psychotropic medication and learning disability. In: Fraser W,

Kerr M, eds. Seminars in the psychiatry of learning disabilities, 2nd

edn. London: Royal College of Psychiatrists, 2003.

� 2009 Published by Elsevier Ltd.

Practice points

C The three golden rules of prescribing in patients with learning

disability and mental illness:

B Start low

B Go slow

B Keep the number of drugs low

C Drug treatment of mental illness in learning disability

B Must be initiated as part of a wider plan

B Is likely to cause central nervous system side-effects

B Should be based on diagnosis, not behaviour

B Should be based on a cautious approach

B But ‘when in doubt, don’t use drugs’ must be tempered

with ‘when confident of diagnosis, do’

ASSESSMENT & MANAGEMENT

Barnard L, Young AH, Pearson J, et al. A systematic review of atypical

antipsychotics in autism. J Psychopharmacol 2002; 16: 93e101.

Child and learning disability psychopharmacology. J Psychopharmacol

1997; 11: 291e4.

Kalachnik JE. Measuring the side effects of psychopharmacologic medi-

cation in individuals with mental retardation and developmental

disabilities. Ment Retard Dev Disabil Res Rev 1999; 5: 348e59.

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learning disability. Irish J Psychol Med 2003; 20: 101e4.

Sevin JA, Bowers-Stevens C, Hamilton ML, Ford A. Integrating behavioral

and pharmacological interventions in treating clients with psychiatric

disorders and mental retardation. Res Dev Disabil 2001; 22: 463e85.

Taylor D, Paton C, Ferwin R. Maudsley prescribing guidelines, 9th edn.

London: Informa Healthcare, 2007.

Vanstralen M, Holt G, Bouras N. Adults with learning disabilities and

psychiatric problems. In: Fraser W, Kerr M, eds. Seminars in the

psychiatry of learning disabilities, 2nd edn. London: Royal College of

Psychiatrists, 2003.

PSYCHIATRY 8:10 415 � 2009 Published by Elsevier Ltd.