CHAPTER 4
PSYCHIATRIC DISORDERS AND CHALLENGING BEHAVIOUR
DAVID CLARKE , MEERA ROY
INTRODUCTION
People
with learning disabilities, like everyone else, may have a psychiatric illness.
It is important to make a distinction between learning disability which
is a “condition of arrested or incomplete development of the mind,
characterised by impairment of skills manifested during the developmental
period, contributing to the overall intelligence” (ICD-10, WHO) and
psychiatric disorder which Michael Rutter defined as “abnormalities of
emotions, behaviour, relationships or thinking which are inconsistent with the
patient’s intellectual level and of sufficient duration or severity to cause
persistent suffering or handicap to the person and/or distress and disturbance
to those in daily contact with him or her” (Rutter, et al 1970).
An individual, therefore, can have a learning disability and a
psychiatric disorder in addition to it. The
impact of having two conditions could mean that the resulting disability may be
more than if either of them existed on their own.
HOW COMMON IS
PSYCHIATRIC DISORDER?
Rutter
et al (1970) found that emotional and behaviour disorders were more common in
children with intellectual retardation. They
found a five fold increase in such disorders among children who had disorders of
the nervous system, such as cerebral palsy and epilepsy. Corbett (1979) surveyed
children and adults with severe and profound learning disabilities and found
that 47% of the children and 37% of the adults had a psychiatric disorder.
Psychiatric disorders occur more commonly in elderly people with learning
disabilities than they do in the general elderly population (Cooper, 1997).
CAUSES OF INCREASED
PREVALENCE
The
lifetime prevalence of psychotic disorders in people with learning disabilities
is about five times that of the general population. There does not appear to be a single cause for it to be so.
This may be the result of interplay of several factors.
A learning disability is often a marker for underlying brain dysfunction
or structural damage. This may
itself lead to both the cognitive impairment and the psychiatric disorder.
The psychological “stress” caused by associated disabilities such as
epilepsy or cerebral palsy may make the individual more susceptible.
Behaviour and emotional disorder may be the presenting symptom of a
physical condition such as a severe respiratory tract infection or thyroid
dysfunction. People with learning
disabilities are at risk of having less control over their lives compared to
their peers. This may result in
unexpected or unwanted changes, such as a move to an unfamiliar living
environment, which may precipitate a psychiatric illness. Any associated
communication difficulties may compound a problem such as
bereavement, making it difficult to come to terms with grief.
Social consequences of the learning disability, such as difficulty in
finding socially valued employment, may lower self-esteem and contribute to the
increased risk of psychiatric disorder. Co-existing epilepsy or a psychiatric
disorder in adolescence may result in an individual not attaining their
potential. Other risks factors
result from particular causes of learning disability, such as the much increased
risk of Alzheimer type dementia associated with Down syndrome. Thus, there is
complex interplay of
BEHAVIOUR DISORDER OR
MENTAL ILLNESS ?
It
is important to make a distinction between behaviour disorders and abnormal
behaviours which are the result of an underlying mental illness.
When a problem behaviour is the manifestation of a mental illness, e.g.
masturbating in public places being a symptom of mania, it is unlikely to
respond to behavioural treatment but will disappear with appropriate medication.
However, people with learning disabilities may present with behaviours
which are not the result of an illness for a variety of reasons.
It may be that they are bored and not appropriately occupied, or their
living environment may be noisy and crowded, with difficulty obtaining attention
from carers. Problem behaviours may arise through attempts to communicate
emotions such as misery or anxiety. The
behaviour may be the result of physical discomfort, e.g. constipation or pain,
or may be a symptom of an additional disability e.g. stereotyped behaviours
associated with autism. Self injury
may have many different functions for one individual and factors initiating such
behaviours (such as boredom) may be superseded by other changes (such as effects
on neuromodulating compounds that alter pain sensation and mood).
A knowledge of vulnerabilities associated with specific conditions (e.g.
proneness to ear infections in people with Down Syndrome and Fragile X Syndrome)
allows physical causes of challenging behaviours to be identified and dealt with
and, with a knowledge of the person’s coping strategies may identify
psychological stressors.
CHALLENGING BEHAVIOUR
The
term ‘challenging behaviour’ is sometimes used to describe
“behaviours
of such an intensity, frequency or duration that the physical safety of the
person or others is likely to be placed in serious jeopardy, or that behaviour
that is likely to seriously limit or delay access to or use of ordinary
community facilities” (Emerson, et al, 1987)
and
in itself is not a clinical diagnosis. The
onus is on professionals like psychiatrists, psychologists and nurses to make
accurate assessments and diagnoses and to help the person with a learning
disability.
It
is important that accurate diagnoses are made before treating any condition and
the diagnosis of psychiatric disorder in people with learning disabilities is no
different. Diagnoses are helpful because they predict responses to treatment,
and prognosis. There are certain
special issues that merit discussion here. Any illness can cause an impairment and may lead to
disability. The person with a
learning disability is already burdened with one.
An undiagnosed and untreated mental illness will prevent the individual
from achieving their potential. Consider
the example of a man with moderate learning disabilities living at home with his
parents who shows periodic behaviour disturbance consisting of aggression,
hyperactivity and poor sleep. If
the recurrent mood disorder is not diagnosed and treated, he may end up being
admitted to a hospital as his parents may not be able to cope.
It may jeopardise his day activities and prevent him from going to the
local shops. Thus, it will impact
on his development and quality of life.
DIAGNOSIS
The
diagnosis of mental illness in people with learning disabilities can be
problematic, especially if the diagnosis is one (like schizophrenia) which
depends on the communication of complex subjective experiences to the examining
clinician. Language skills
may be limited or absent, depending on the degree of disability the individual
has. People with mild learning
disabilities are usually able to communicate how they feel, and it is possible
to examine their thought processes. However,
the assessment of whether a belief is truly delusional (i.e. false, held with
conviction and not explicable on the basis of the person’s cultural and
educational background) may be difficult. People
with learning disabilities may have false beliefs arising from misunderstanding,
lack of community contact or due to an autistic disorder.
Auditory hallucinations may be difficult to distinguish from practice
vocalisations, conversations with (developmentally appropriate) invisible
friends or stereotyped utterances associated with autism.
Similar problems may arise with other phenomena such as thought disorder
and a high degree of language sophistication is necessary to describe
passivity phenomena where for example, the individual may feel that they
are being controlled (Reid, 1994). More
often than not, people with mild learning disabilities are brought to
appointments by family members and carers. It is important to get corroborative
history from them to get a comprehensive picture of the difficulties. Another
difficulty arises when the carer does not know the person with a learning
disability well.
People
with more severe learning disabilities and little communication present a
different kind of challenge, because they may not be in a position to
communicate about their inner world. Here
a longitudinal history from a carer or family member who knows the individual
well over a long period of time is crucial.
Changes in sleep pattern, appetite, mood, self help skills and
sociability will provide valuable clues in the diagnosis of an underlying
psychiatric condition, and it is often possible to establish diagnoses of mood
disorders for people with such disabilities.
Psychiatrists
usually rely on their skills in history taking and examination to come to a
diagnosis of a mental illness. It
may be necessary to see the individual on several occasions and in a variety of
settings where he or she is more at ease, and to interview carers in both day
and residential settings, interview family members, and examine previous case
notes before a diagnosis can be made. Rating
scales such as the Leicester, Kettering Depression Rating Scale and
questionnaires such as the West Midlands Autism Questionnaire and Standardised
Assessment of Personality Disorders can be used as adjuncts as well as scales
used in general adult psychiatry such as the Hamilton Scale for Depression, etc.
Moss
et al (1996) developed the Psychiatric Assessment Scale for Adults with
Developmental Disability (PAS-ADD) derived from the Present State Examination (PSE)
developed for use within general psychiatry. The Aberrant Behaviour Checklist (Aman et al, 1985) and
Diagnostic Assessment Scale for the Severely Handicapped (DASH) developed by
Matson et al (1991) were developed for use with people with severe learning
disabilities while the Reiss Screen for Maladaptive Behaviour (Reiss, 1988) and
the Psychopathology Inventory for Mentally Retarded Adults (PIMRA, Matson et al,
1984) were developed for use with people with mild to moderate learning
disabilities. These rating scales
may be helpful as research tools or to measure change occurring with treatment.
Diagnoses
of psychiatric disorders are based on clinical guidelines contained in two
classificatory systems. The
Diagnostic and Statistical Manual (DSM) is the system used by the American
Psychiatric Association, the latest version being DSM IV.
The World Health Organisation published the 10th revision of the
International Classification of Diseases, the ICD10, in 1992.
The latter is more commonly used in the United Kingdom.
The WHO introduced the ICD10 Guide for Mental Retardation (this being the
commonest term used internationally to describe Learning Disabilities) in 1996.
This guide was prepared to assist those working in the field of learning
disabilities to make the best use of the ICD10.
MULTIAXIAL DIAGNOSIS
People
with learning disabilities usually have multiple problems.
To describe these adequately, it is usually necessary to use several
diagnoses. The ICD10 Guide for
Mental Retardation (WHO, 1996), therefore, recommends a multiaxial system of
diagnosis to record different kinds of features in the individual with learning
disabilities. They are as follows:
|
Axis
I |
The
severity of learning disabilities and problem behaviours. |
|
Axis
II |
Associated
medical conditions (e.g.
epilepsy, Down Syndrome). |
|
Axis
III |
Associated
psychiatric disorders including pervasive developmental disorders, e.g.
autism |
|
Axis
IV |
Global
assessment of psychosocial disability (using the WHO Short Disability
Assessment Schedule) |
|
Axis
V |
Associated
abnormal psychosocial situations(e.g. institutional upbringing) . |
Psychiatric
disorders have been classified in many ways, most authors making a distinction
between severe disorders (such as psychoses, in which reality-testing is
impaired) and less severe disorders. Psychoses may be symptomatic (such as the
dementia accompanying Huntington’s disease) or “functional” (e.g.
schizophrenia). The term
“functional” was used to describe psychotic disorders that were not
associated with gross brain dysfunction. It continues to be used, in the absence
of a more suitable term, in spite of evidence that disorders such as
schizophrenia are associated with subtle changes in brain structure and
function, detectable using modern neuro-imaging techniques.
Terms used to describe symptoms of psychiatric illness include delusions
- false beliefs that are held with absolute conviction, and that are not
understandable give the patient’s social, education and cultural background
and hallucinations - perceptions that occur without a stimulus.
They are often auditory (heard), as in schizophrenia, or visual (seen),
as in delirious states. It is useful to consider the classes of mental illnesses
and their presentation in people with learning disabilities.
SCHIZOPHRENIA
Schizophrenia
is characterised by fragmentation of thinking and delusions and hallucinations
of particular, often bizarre, types. Schizophrenia
means ‘fragmented mind’ and its popular use to describe ‘a split
personality’ is incorrect. Schizophrenia
may be the end result of more than one illness or process, and for this reason
some clinicians prefer the collective term ‘the schizophrenias’.
Fragmentation of thought (often manifest as disordered speech, sometimes
by the experiences of having thoughts inserted into or withdrawn from the mind)
is a key feature. Delusions of
control or influence, or other bizarre delusions, specific types of auditory
hallucinations, movement abnormalities and emotional abnormalities and disorders
of the perception of free will may occur. Acts or emotions may be perceived as
made or imposed by some external agency (“passivity experiences”).
Different types of schizophrenia are recognised, each with a
characteristic pattern of symptoms and course.
Schizophrenia is very rarely associated with dangerously aggressive
behaviour to other people. When this does occur in association with schizophrenia, the
person concerned often has other problems such as substance abuse or a
personality disorder.
The
prevalence of schizophrenia is higher in the learning disabled population (about
3% lifetime risk) compared to the general population (less than 1% lifetime
risk). The prevalence among people
with severe learning disabilities is impossible to ascertain because most such
people cannot describe the characteristic experiences (Reid, 1994).
As
the diagnosis of schizophrenia and related disorders may be difficult to
establish, relatively non-specific categories (such as non-organic psychotic
disorder) may have to be used. It may be difficult to differentiate between sub
types of schizophrenia. The course of the disorder, and changes which occur over
time, should be taken into account. A
decline in social, self care or other skills and development of unusual or
apparently irrational maladaptive behaviour may be the earliest manifestation.
Symptoms commonly reported include auditory hallucinations. Unexplained
bizarre behaviours which are out of character and sustained in different
environments should raise the possibility that the person may have delusions or
hallucinations (ICD 10 Guide, 1996).
MOOD DISORDERS
Affective
Disorders or Mood Disorders are characterised by disturbances in mood and
vitality, resulting in depression (with slowed thinking and impaired
concentration, poor appetite, pessimism and ideas of guilt, self-reproach and
self-harm) or elation (with euphoria, over-activity, talkativeness and ideas of
grandiosity).
Depressive
disorders are characterised by low
mood, loss of interest or pleasure in activities which are normally pleasurable,
early waking, worsening of low mood in the morning, reduction in activity and
appetite, weight loss and reduction in libido.
Depressive illness (or “clinical depression”) differs from everyday
unhappiness or understandable low mood through the presence of these additional
features, although a depressive syndrome may be precipitated by an event (such
as bereavement) that would be expected to cause unhappiness.
Severe depressive episodes may be accompanied by psychotic features such
as delusions or hallucinations. Depressive
disorders are associated with a much increased risk of self-harm.
This may take the
Manic
and hypomanic states are characterised by elated mood (sustained for several
days) accompanied by features such as overactivity, talkativeness, disinhibition,
decreased need for sleep and distractibility.
Mania is the more severe form of the disorder, and may be accompanied by
delusions or hallucinations. Bipolar
disorders are characterised by recurrent episodes of abnormal mood state, at
least one of which has been manic or hypomanic.
Affective
disorders (depression, manic-depressive illness and related conditions) are
about five times more common among people with learning disabilities, (both mild
and severe) and the point prevalence in hospital studies is usually found to be
around 2%.
Diagnosis
may be hindered by the person’s inability to communicate how he or she may be
feeling. Disturbances in appetite,
sleep pattern, interest in activities which give pleasure, self help skills,
sexual behaviour and level of arousal are useful indicators. Episodic self
injurious behaviour, screaming and withdrawal may often be diagnostic of mood
disorders, functioning as depressive “equivalents” (Marston et al,1997).
DELIRIUM AND DEMENTIA
Dementias
are characterised by progressive impairments in memory and other cognitive
abilities, leading to impaired judgement and thinking.
There is (at least initially), no reduction in the level of consciousness
as seen in delirium, and other symptoms (such as emotional liability,
irritability, apathy or coarsening of social behaviour) may be present.
For a confident diagnosis, symptoms should have been present for at least
six months.
Delirium
is characterised by a reduction in awareness of the environment (“clouded
consciousness”), memory impairments, disorientation, changes in the pattern of
activity (such as increased reaction time) and disturbance of the sleep-wake
cycle.
Both
dementia and delirium are characterised by the disorientation (the person has a
distorted sense of time, where (s)he is, and who other people are),
misinterpretation of the environment (e.g. imagining a bedroom to be a prison),
and illusions or hallucinations (usually visual - such as seeing bodies fall
past a window).
Dementia
is associated with some specific causes of a learning disability, notably Down
Syndrome (Prasher, 1993). Cooper
(1997) found that the rate of dementia in older people with learning
disabilities was four times higher than the general population.
Other causes of cognitive deterioration, like thyroid dysfunction and
affective disorder masquerading as dementia, have to be ruled out.
Assessment of adaptive behaviours longitudinally is a useful diagnostic
tool.
Delirium
may be the result of physical illness or intoxication.
The risk of these disorders is increased among people with learning
disabilities due to the presence of associated physical disorders and drug
treatments for problems such as epilepsy.
NEUROTIC, STRESS RELATED
AND SOMATOFORM DISORDERS
These
include phobias (fears of objects or situations), panic disorder (characterised
by unpredictable, intense episodes of fear with an abrupt onset, lasting
minutes, and with features such as palpitations, sweating, or a feeling of
“going mad”), generalised anxiety, conversion (“hysterical”) disorders
and obsessive-compulsive disorder which is characterised by obsessions
(recurrent, unpleasant, intrusive, thoughts which are resisted and which cause
distress) or compulsions (actions which the person carries out repetitively
while acknowledging that there is no reason to do so). Compulsive rituals may be difficult to distinguish from
stereotyped activities, which are usual among people with autism.
The history of a change in behaviour, and the presence of resistance to
the activity, may help diagnosis. Some
recent research suggests that rituals and stereotyped, repetitive behaviours may
not be as distinct as previously thought, and may share underlying biological
mechanisms.
Some
neuroses appear to be common in clinical practice, but this area has been less
well- researched than more severe disorders.
EATING DISORDERS
Over
eating and unusual dietary preferences are relatively common in people with
learning disabilities but eating disorders such as Anorexia Nervosa and Bulimia
are less frequent. The factors
which are thought to contribute to these disorders like cultural expectations
and societal pressures to be thin may
not have affected people with learning disabilities who until recently, were
segregated in institutions. Perhaps
they may become more common with the implementation of community care (ICD10
Guide, WHO, 1996). Regurgitation,
rumination and psychogenic vomiting are seen in people with learning
disabilities.
PERSONALITY DISORDERS
Personality
Disorders are deeply ingrained and enduring behaviour patterns manifesting
themselves as inflexible responses to a broad range of personal and social
situations. Such behaviour patterns
tend to be stable and to encompass multiple domains of behaviour and
psychological functioning (ICD10, WHO).
Corbett
(1979) reported a prevalence rate of around 25% for behaviour/personality
disorder in his Camberwell study. The
largest category consisted of people with impulsive or immature behaviour
patterns. Khan et al (1997) found
that 31% of a community sample had a personality disorder.
These
conditions are more easily diagnosed in people with mild learning disabilities
and the associated difficulties may result in contact with the criminal justice
system.
AUTISM AND RELATED
DISORDERS
Autistic
disorders, also called Pervasive Developmental Disorders (PDDs) include
Childhood Autism, Atypical Autism, Asperger’s Syndrome and some other
categories. They are characterised
by impairments in three areas:-
·
Language may
be delayed, abnormal or absent. The
abnormalities may be gross, with muteness and no development of alternative mans
of communication (such as sign language) or subtle, with abnormal intonation,
pedantic speech with a tendency to interpret remarks concretely and inability to
tailor speech to the social context.
·
Reciprocal
social interactions are abnormal, with aloofness, solitariness or awkwardness in
social situations; abnormalities of gaze; disinterest or distaste for physical
contact and inability to ‘play by the rules’ in conversation.
·
A
restricted, repetitive, stereotyped repertoire of interests and activities such
as collecting shiny objects or pieces of string; twirling or spinning objects;
hand flapping; unusual fears or hobbies (collecting car registration numbers;
memorising telephone numbers or bus routes; reciting varieties of carrot);
insistence on sameness with intolerance of changes to routines, etc.
Autism and
autistic spectrum disorders are discussed in Chapter 7.
BEHAVIOURAL AND
PSYCHIATRIC DISORDERS WITH ONSET IN CHILDHOOD
These
include hyperkinetic disorders, characterised by overactivity and deficits in
attention; conduct and emotional disorders, and other disorders with an onset
that is usually in childhood such as enuresis (bedwetting), tics (sudden,
involuntary, rapid, non-rhythmic, stereotyped movements or vocalisations) and
Tourette syndrome (combined vocal and multiple motor tics).
Some of these disorders (such as hyperkinetic syndromes and tics) are not
uncommon among people with learning disabilities, especially if the learning
disability results from a genetic or metabolic abnormality.
Behavioural
syndromes associated with particular disorders causing learning disabilities is
further discussed in Chapter 3.
ASSESSMENT AND TREATMENT
The
last thirty years has seen the closure of Learning Disability hospitals and care
in the community for people with learning disabilities.
They are no longer considered by professionals and some others as people
who should be hidden away from sight and encouraged to take their rightful place
in society. This has meant that
they are finally expected to use mainstream services, including health services,
for their needs.
The
expectation is that people with learning disabilities will go to general
practitioners for their physical health problems and will be seen by appropriate
hospital doctors, if necessary, to remain well. The psychiatrists in the field
of learning disabilities are no longer the right people to look after physical
problems, though they still sometimes have to advocate on behalf of their
patients. However, it has been
established that people with learning disabilities have higher rates of mental
illness compared to the general population and the presentation of the illness
requires particular expertise, diagnosis and treatment.
Therefore, people with learning disabilities at the present time appear
to need a specialised neuropsychiatric service, but the emphasis for treatment
should be that wherever possible, people with learning disabilities should use
mainstream services used by other ordinary people.
These
issues are further discussed in Chapter 8 on assessment and treatment and
Chapter 10 service provision.
When
any treatment is provided, attention must be given to the likely benefits and
the potential risks. No effective
treatment (biological or psychological) is free of potential unwanted effects.
When prescribing for people whose ability to understand and communicate
may be impaired, the tailoring of treatment to maximise potential gains and
minimise adverse effects is especially important.
This process entails a knowledge of both the treatment and common adverse
effects and problems to which the individual is vulnerable.
For example, a man who has a schizophrenic illness and who is prone to
constipation would be prescribed a different antipsychotic drug to a man prone
to diarrhoea.
The
effectiveness of drug treatments for severe psychiatric disorders has been
established beyond doubt, but the treatment of many “challenging” behaviours
associated with learning disabilities is empirically based (Clarke, 1997).
This is partly a result of methodological problems with clinical trials
(e.g. ensuring adequate numbers of people with the same psychiatric disorder and
the same cause and severity of learning disability).
Many reports in the literature describe the treatment of small numbers of
people with learning disability, or single cases.
The results often imply that some, but not most, people with a particular
problem benefit from the treatment. Clinicians
are, therefore, usually more cautious when using drugs to treat such disorders,
because the risks remains but the benefits may not be so clearly established.
The
drugs used in people with learning disabilities to treat mental illness are no
different from those used in the general population. The psychiatrist is guided by the British National Formulary
on dosage and side effects. Schizophrenia,
mania and other psychotic disorders are treated with antipsychotic drugs.
Chlorpromazine, trifluoperazine, thioridazine and haloperidol are older
drugs with more side effects. As in
general psychiatry, the trend is to use newer, cleaner drugs such as risperidone.
Zuclopenthixol appears to be effective in people who are aggressive.
For
patients presenting with a depressive illness, again the trend is to use the
newer antidepressants like the Specific Serotonin Re-uptake Inhibitors such as
paroxetine as they cause less side effects.
This is particularly important as they may be on other drugs such as
anticonvulsants. Lithium and
carbamazepine are used as mood stabilisers in those with bipolar affective
disorders. Liquid preparations of
medication are helpful as sometimes patients may either chew tablets or find it
difficult to swallow them. Depot
preparations of antipsychotic drugs are useful in patients where compliance may
be questionable. Electroconvulsive
therapy is only rarely used in people with learning disabilities.
When
a person with a learning disability has an additional mental illness, medication
will only be one aspect of the treatment. The psychiatrist in learning disabilities is a member of a
multidisciplinary team and other professionals will have important contributions
to ensure the patient’s well being. These issues are further discussed in Chapter 8 and 9.
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