Elita Smiley

Adults with intellectual disabilities : prevalence, incidence and remission of aggressive behaviour and related factors

INTRODUCTION Aggressive behaviours can be disabling for adults with intellectual disabilities (ID), with negative consequences for the adult, their family and paid carers. It is surprising how little research has been conducted into the epidemiology of these needs, given the impact they can have. This study investigates point prevalence, 2-year incidence and 2-year remission rates for aggressive behaviour (physically aggressive, destructive and verbally aggressive), and it investigates which factors are independently associated with aggressive behaviour. METHODS All adults with ID - within a geographically defined area of Scotland, UK - were recruited to a longitudinal cohort. At baseline, assessments were undertaken of demography, lifestyle, supports, development, problem behaviours, disabilities and physical and mental health. These were repeated for a 2-year period. RESULTS At baseline, the participation rate was 1023 (65.5%). After 2 years, the cohort retention was 651 adults. The point prevalence of Diagnostic Criteria for Psychiatric Disorders for Use with Adults with Learning Disabilities/Mental Retardation (DC-LD) aggressive behaviour was 9.8% (95% confidence interval = 8.0-11.8%), 2-year incidence was 1.8%, and 2-year remission rate from all types of aggressive behaviour meeting DC-LD criteria was 27.7%. The factors independently associated with aggressive behaviours were lower ability, female gender, not living with a family carer, not having Down syndrome, having attention-deficit hyperactivity disorder and having urinary incontinence. Incidence of aggressive behaviour meeting DC-LD criteria in adult life is similar to that for each of psychotic, anxiety and organic disorders. CONCLUSIONS Aggressive behaviour is common among adults with ID, but contrary to previous suggestions, more than a quarter remit within the short to medium term. This is important knowledge for professionals as well as the person and her/his family and paid carers. There is much yet to learn about the mechanisms underpinning aetiology and maintenance of aggressive behaviour in this population, and exploratory epidemiological investigations such as this have a role to play in progressing research towards further hypothesis testing and trials to influence clinical practice, service development and policy.

Adults with intellectual disabilities: prevalence, incidence and remission of self-injurious behaviour, and related factors

BACKGROUND Self-injurious behaviour (SIB) is a serious condition, with implications for the person, their family and financial costs to the state providing care. The previously reported prevalence of SIB has ranged from 1.7% to 41%, or 1.7%-23.7% in community studies. There has been little study of remission rate, and incidence has not previously been reported. SIB has been reported to be individually associated with lower ability, autism and communication impairments, but given the inter-relationships between these three factors, it is not known whether they are independently associated with SIB. This study investigates the point prevalence, incidence and remission rates of SIB among the adult population with intellectual disabilities (ID), and explores which factors are independently associated with SIB. METHOD A prospective cohort study design was used in a general community setting. The participants were all adults (16 years and over) with ID in a defined geographical area. Individual assessments were conducted with all participants. RESULTS The point prevalence of SIB (as defined by DC-LD) was 4.9%, the two-year incidence was 0.6%, and two-year remission rate was 38.2%. Independently related to SIB were: lower ability level, not living with a family carer, having attention deficit hyperactivity disorder, visual impairment, and not having Down syndrome. Other factors, including communication impairment, autism, and level of deprivation of the area resided within, were not related. CONCLUSIONS SIB is not as enduring and persistent as previously thought; a significant proportion gains remission in this time period. This should provide hope for families, paid carers and professionals, and reduce therapeutic nihilism. Our study is a first tentative step towards identifying risk-markers for SIB, and developing aetiological hypotheses for subsequent testing. The extent to which SIB may be a relapsing-remitting (episodic) condition requires further investigation, so does further hypothesis-based investigation of factors that might be predictive of incidence of, and remission from, SIB.

The Prevalence and Incidence of Mental Ill-Health in Adults with Down Syndrome.

BACKGROUND While there is considerable literature on adults with Down syndrome who have dementia, there is little published on the epidemiology of other types of mental ill-health in this population. METHOD Longitudinal cohort study of adults with Down syndrome who received detailed psychiatric assessment (n = 186 at the first time point; n = 134 at the second time point, 2 years later). RESULTS The prevalence of Down syndrome for the 16 years and over population was 5.9 per 10 000 general population. Point prevalence of mental ill-health of any type, excluding specific phobias, was 23.7% by clinical, 19.9% by Diagnostic Criteria for Psychiatric Disorders for use with Adults with Learning Disabilities/Mental Retardation (DC-LD), 11.3% by ICD-10 Classification of Mental and Behavioural Disorders: Diagnostic Criteria for Research (DCR-ICD-10) and 10.8% by Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition Revised (DSM-IV-TR) criteria. Two-year incidence of mental ill-health of any type was 14.9% by clinical and DC-LD, 9.0% by DCR-ICD-10 and 3.7% by DSM-IV-TR criteria. The highest incidence was for depressive episode (5.2%) and dementia/delirium (5.2%). Compared with persons with intellectual disabilities (ID) of all causes, the standardized rate for prevalence of mental ill-health was 0.6 (0.4-0.8), or 0.4 (0.3-0.6) if organic disorders are excluded, and the standardized incidence ratio for mental ill-health was 0.9 (0.6-1.4), or 0.7 (0.4-1.2) if organic disorders are excluded. Urinary incontinence was independently associated with mental ill-health, whereas other personal factors, lifestyle and supports, and other types of health needs and disabilities were not. CONCLUSIONS Mental ill-health is less prevalent in adults with Down syndrome than for other adults with ID. The pattern of associated factors differs from that is found for other adults with ID, with few associations found. This suggests that the protection against mental ill-health is biologically determined in this population, or that there are other factors protective for mental ill-health yet to be identified for the population with Down syndrome.

An epidemiological investigation of affective disorders with a population-based cohort of 1023 adults with intellectual disabilities

BACKGROUND Intellectual disabilities (ID) are common and lifelong. People with ID have health inequalities compared with the general population, but little is known about the epidemiology of affective disorders in this population. This study was undertaken to determine the point prevalence of affective disorders, and to investigate factors associated with depression. METHOD This population-based study (n=1023) included comprehensive individual assessments with each person. A two-stage process was used for diagnosis of affective disorders. Factors independently associated with depression were investigated through logistic regression analysis. RESULTS The point prevalence was higher than that reported previously for the general population; DC-LD yielded 3.8% for depression and 0.6% for mania. Additionally, 1.0% had bipolar disorder currently in remission, and 0.1% first episode of mania currently in remission. Similar to general population findings, depression was associated with female gender, smoking, number of preceding family physician appointments, and preceding life events. Important differences were the association of not having a hearing impairment, and the trends for not living in deprived areas, and being married. Unlike general population findings, not having daytime occupation and obesity were not independently associated; nor was previous long-stay hospital residence, severity of ID, or sensory impairments. CONCLUSIONS This study has found a high point prevalence of affective disorders in adults with ID. The factors associated with depression have differences to general population findings. An understanding of this is important in order to develop appropriate interventions, public strategy and policy, to reduce existing health inequalities.

The prevalence and incidence of mental ill-health in adults with autism and intellectual disabilities

The prevalence, and incidence, of mental ill-health in adults with intellectual disabilities and autism were compared with the whole population with intellectual disabilities, and with controls, matched individually for age, gender, ability-level, and Down syndrome. Although the adults with autism had a higher point prevalence of problem behaviours compared with the whole adult population with intellectual disabilities, compared with individually matched controls there was no difference in prevalence, or incidence of either problem behaviours or other mental ill-health. Adults with autism who had problem behaviours were less likely to recover over a two-year period than were their matched controls. Apparent differences in rates of mental ill-health are accounted for by factors other than autism, including Down syndrome and ability level.

Prevalence of, and factors associated with, problem behaviors in adults with intellectual disabilities.

This study aimed to determine the prevalence of problem behaviors in adults with intellectual disabilities and to investigate which factors are independently associated with problem behaviors. A population-based cohort (n = 1023) had comprehensive individual assessments. Data were examined using multivariate logistic regression. The prevalence of problem behaviors was 22.5% (psychiatrists’ opinion) or 18.7% (DC-LD criteria). Factors independently associated with problem behaviors were lower ability level, female gender, living in a congregate care setting or with paid carer support (rather than living with a family carer), having urinary incontinence; visual impairment, not having Down syndrome, and not having severe physical disabilities. Further studies focusing on the etiology, course, and treatment of problem behaviors are required.

Prevalence and associations of anxiety disorders in adults with intellectual disabilities

BACKGROUND Anxiety disorders are known to be common in the general population. Previous studies with adults with intellectual disabilities (IDs) report a prevalence of general anxiety disorder ranging from <2% to 17.4%. Little is known about associated factors in this population. This study investigates point prevalence of anxiety disorders and determines the factors independently associated with them. METHODS Information was collected with 1023 adults with IDs who participated in a large-scale, population-based study. All had a comprehensive physical and mental health assessment. The point prevalence of anxiety disorders according to different diagnostic criteria was determined, as were independently associated factors by using logistic regression analysis. RESULTS Three point eight per cent (95% CI=2.7-5.2%) of the cohort had an anxiety disorder at the time of assessment. Generalised anxiety disorder was the most common (1.7%), then agoraphobia (0.7%). Factors independently associated with having an anxiety disorder were not having any daytime employment, and having a recent history of life events. Having previously been a long-term hospital resident was independently associated with not having an anxiety disorder. CONCLUSIONS Anxiety disorders are common in the ID population. At times of significant life events, it might be sensible for carers to consider proactively providing additional support and being vigilant to seek early health-care interventions should there be any suggestion of emerging mental ill-health. The study further highlights the range of mental ill-health that is experienced by the population with IDs, and therefore the need for appropriate care, supports and development of effective interventions.

A cohort study of the prevalence of sleep problems in adults with intellectual disabilities

Previous studies of the prevalence of sleep problems in adults with intellectual disabilities (ID) are affected by small, potentially biased samples and other limitations. This study aims to determine the prevalence and associations of sleep problems in the adult population with ID. The 4‐week period prevalence of sleep problems was determined in a cross‐sectional study of all adults with ID in a defined geographical area. Sleep problems were identified using the Psychiatric Assessment Scale for Adults with Developmental Disabilities (PAS‐ADD) checklist and categorized as initial insomnia, early morning wakening and broken sleep. A fourth, composite, variable of significant sleep problem was also derived. Of the 1023 adults with ID who participated, 9.2% had experienced a significant sleep problem, during the 1‐month period. Individuals with a significant sleep problem are more likely to have mental ill‐health [odds ratio (OR) = 5.53, 95% confidence interval (CI) 3.52–8.69], problem behaviours (OR = 2.06, 95% CI: 1.25–3.41) and respiratory disease (OR = 2.03, 95% CI: 1.27–3.26). There is a positive association between visual impairment and initial insomnia (OR = 1.91, 95% CI: 1.21–3.04). Although a diagnosis of epilepsy is not associated with sleep problems, the finding that individuals taking antiepileptic medication are more likely to experience broken sleep (OR = 1.73, 95% CI: 1.13–2.66) suggests that medication side effects may impact on sleep of individuals with ID. The results suggest that there is a need to further examine the relationship between sleep problems and co‐morbid health problems, which would inform the development of interventions, and trials of their efficacy.

Neighbourhood Deprivation, Health Inequalities and Service Access by Adults with Intellectual Disabilities: A Cross-Sectional Study.

BACKGROUND Adults with intellectual disabilities (IDs) experience health inequalities and are more likely to live in deprived areas. The aim of this study was to determine whether the extent of deprivation of the area a person lives in affects their access to services, hence contributing to health inequalities. METHOD A cross-sectional study design was used. Interviews were conducted with all adults with IDs within a defined location (n = 1023), and their medical records were reviewed. The extent of area deprivation was defined by postcode, using Carstairs scores. RESULTS Area deprivation did not influence access to social supports, daytime primary health-care services or hospital admissions, but people in more deprived areas made less use of secondary outpatient health care [first contacts (P = 0.0007); follow-ups (P = 0.0002)], and more use of accident and emergency care (P = 0.02). Women in more deprived areas were more likely to have had a cervical smear; there was little association with other health promotion uptake. Area deprivation was not associated with access to paid employment, daytime occupation, nor respite care. These results were essentially unchanged after adjusting for type of accommodation and level of ability. CONCLUSIONS Deprivation may not contribute to health inequality in the population with IDs in the same way as in the general population. Focusing health promotion initiatives within areas of greatest deprivation would be predicted to introduce a further access inequality.

Problem behaviours and symptom dimensions of psychiatric disorders in adults with intellectual disabilities: An exploratory and confirmatory factor analysis.

BACKGROUND The limited evidence on the relationship between problem behaviours and symptoms of psychiatric disorders experienced by adults with intellectual disabilities leads to conflict about diagnostic criteria and confused treatment. This study examined the relationship between problem behaviours and other psychopathology, and compared the predictive validity of dimensional and categorical models experienced by adults with intellectual disabilities. METHODS Exploratory and confirmatory factor analyses appropriate for non-continuous data were used to derive, and validate, symptom dimensions using two clinical datasets (n=457; n=274). Categorical diagnoses were derived using DC-LD. Severity and 5-year longitudinal outcome was measured using a battery of instruments. RESULTS Five factors/dimensions were identified and confirmed. Problem behaviours were included in an emotion dysregulation-problem behaviour dimension that was distinct from the depressive, anxiety, organic and psychosis dimensions. The dimensional model had better predictive validity than categorical diagnosis. CONCLUSIONS International classification systems should not include problem behaviours as behavioural equivalents in diagnostic criteria for depression or other psychiatric disorders. Investigating the relevance of emotional regulation to psychopathology may provide an important pathway for development of improved interventions. WHAT THIS PAPER ADDS There is uncertainty whether new onset problem behaviours or a change in longstanding problem behaviours should be considered as symptoms of depression or other types of psychiatric disorders in adults with intellectual disabilities. The validity of previous studies was limited by the use of pre-defined, categorical diagnoses or unreliable statistical methods. This study used robust statistical modelling to examine problem behaviours within a dimensional model of symptoms. We found that problem behaviours were included in an emotional dysregulation dimension and not in the dimension that included symptoms that are typical of depression. The dimensional model of symptoms had greater predictive validity than categorical diagnoses of psychiatric disorders. Our findings suggest that problem behaviours are a final common pathway for emotional distress in adults with intellectual disabilities so clinicians should not use a change in problem behaviours as a diagnostic criterion for depression, or other psychiatric disorders.