Psychometric properties of the revised Developmental Behaviour Checklist scales in Dutch children with intellectual disability

The present study assessed the reliability and validity of the revised scales of the Developmental Behaviour Checklist (DBC) in a Dutch sample of children with intellectual disability (ID). The psychometric properties of the parent and teacher versions of the DBC were assessed in various subsamples derived from a sample of 1057 Dutch children (age range = 6–18 years) with ID or borderline intellectual functioning. Good test–retest reliability was shown both for the parent and teacher versions. Moderate inter‐parent agreement and high one‐year stability was found for the scale scores. Construct validity was satisfactory, although limited by high informant variance. The DBC scales showed good criterion‐related validity, as indicated by significant mean differences between referred and non‐referred children, and between children with and without a corresponding DSM‐IV diagnosis. The reliability and validity of the revised DBC scales are satisfactory, and the checklist is recommended for clinical and research purposes.     

Challenging behaviours should not be considered as depressive equivalents in individuals with intellectual disability

Background Depression is one of the most common forms of psychopathology in people with intellectual disability (ID). The present study evaluated the utility of an expanded assessment of psychiatric symptoms and challenging behaviours, as measured by the Clinical Behavior Checklist for Persons with Intellectual Disabilities (CBCPID). Methods The CBCPID was administered to 92 people with ID, 35 of whom were diagnosed with a depressive disorder. Results Item and factor analysis of the scale indicated that depression was best assessed using the core DSM‐IV symptoms of depressive disorder. Challenging behaviours such as self‐injury or aggression were not closely associated with depression. Short scales using the core DSM‐IV symptoms of depression were highly internally consistent. There was also evidence of the validity of these scales. Conclusions This study found no evidence that challenging behaviours were depressive equivalents in this population. The present authors conclude that the assessment of depression in people with ID should focus on the core DSM‐IV symptoms of depression.     

Psychometric evaluation of a scale to assess satisfaction with life among people with intellectual disabilities living in community residences

Background In the context of a health intervention among people with intellectual disabilities (ID), there was a need to assess satisfaction with some aspects of life, in order to monitor both potential positive and negative effects of the intervention. The aim of the present study was to develop and evaluate an easily administered scale for assessing satisfaction with home environment and leisure time among people with mild or moderate ID, living in community residences. Methods A number of questions were constructed to measure satisfaction with home environment and leisure time. The questions were answered by 132 adults with mild or moderate ID, living in community residences in Sweden. The dimensionality of the scale was evaluated by factor analysis, and the reliability was estimated using Cronbach's alpha coefficients. Results The analysis supported a four‐factor solution with 12 items. The four factors were: (I) Satisfaction with housing environment; (II) Satisfaction with life; (III) Satisfaction with meals; and (IV) Satisfaction with recreational activity. The four factors explained almost 70% of the variance in the data set. Cronbach alpha coefficients for all scales were above 0.70, indicating that the reliabilities of the scales were satisfactory. Correlations between the four sub‐scales ranged from 0.06 to 0.52, indicating low to moderate inter‐correlations between the four sub‐scales. Conclusion The scale has fairly good psychometric properties and is easy to administer. The scale, which can be further improved, can be an important resource in health intervention studies.     

Psychiatric Disorders in Outpatients With Borderline Intellectual Functioning: Comparison With Both Outpatients From Regular Mental Health Care and Outpatients With Mild Intellectual Disabilities

Objective:

In the Netherlands, patients with borderline intellectual functioning are eligible for specialized mental health care. This offers the unique possibility to examine the mix of psychiatric disorders in patients who, in other countries, are treated in regular outpatient mental health care clinics. Our study sought to examine the rates of all main Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition, Text Revision, Axis I psychiatric diagnoses in outpatients with borderline intellectual functioning of 2 specialized regional psychiatric outpatient departments and to compare these with rates of the same disorders in outpatients from regular mental health care (RMHC) and outpatients with mild intellectual disabilities (IDs).

Method:

Our study was a cross-sectional, anonymized medical chart review. All participants were patients from the Dutch regional mental health care provider Rivierduinen. Diagnoses of patients with borderline intellectual functioning (borderline intellectual functioning group; n = 235) were compared with diagnoses of patients from RMHC (RMHC group; n = 1026) and patients with mild ID (mild ID group; n = 152).

Results:

Compared with the RMHC group, psychotic and major depressive disorders were less common in the borderline intellectual functioning group, while posttraumatic stress disorder and V codes were more common. Compared with the mild ID group, psychotic disorders were significantly less common.

Conclusion:

Mental health problems in people with borderline intellectual functioning may not be well addressed in general psychiatry, or by standard psychiatry for patients with ID. Specific attention to this group in clinical practice and research may be warranted lest they fall between 2 stools.     

Psychometric evaluation of a Dutch version of the Mini PAS‐ADD for assessing psychiatric disorders in adults with different levels of intellectual disability

Background People with intellectual disabilities (ID) have an increased vulnerability to develop psychiatric problems. Moreover, the early recognition and the accurate diagnosis of psychiatric disorders in the population of persons with ID are challenging. Method A Dutch version of the Mini PAS‐ADD, which is a screening instrument for identification of mental health problems in people with ID, was evaluated in terms of internal consistency, interinformant reliability, item grouping and criterion validity based on a large‐scale random sample (n = 377) and a clinical sample (n = 99) of adults with ID. Results The Dutch version of the Mini PAS‐ADD showed moderate internal consistency, and moderate concordance among informants. Both aspects of the reliability were comparable for different levels of ID. A factor analysis largely confirmed the scale structure. Concurrent validity with the Reiss Screen for Maladaptive Behavior was high for the Depression, Psychosis and Autism scale. The outcome of the criterion‐validity analysis indicated high specificity. The sensitivity for specific psychiatric disorders by the corresponding scales was moderate, but the general sensitivity for the presence of psychopathology on the basis of any of the scales was satisfying. Conclusions The present research reconfirmed the use of the Mini PAS‐ADD as a primary screening device for the identification of mental health problems among people with ID.     

Reliability and Validity of the HoNOS-LD and HoNOS in a Sample of Individuals with Mild to Borderline Intellectual Disability and Severe Emotional and Behavior Disorders

In this study, psychometric properties of the Health of the Nation Outcome scales (HoNOS) and Health of the Nation Outcome Scales for People with Learning Disabilities (HoNOS-LD) were investigated in a sample (n = 79) of (young) adults with mild to borderline intellectual disability (ID) and severe behavior and mental health problems who were admitted for treatment. Informant pairs were 14 direct care staff and 15 psychiatrists/psychologists who completed both the HoNOS and HoNOS-LD as well as other scales (i.e., Social Functioning Scale for the Mentally Retarded [SRZ-P], Adult Behavior Checklist [ABCL]). Generally, internal consistency was fair to good for both scales, and intraclass coefficients for (sub)scales ranged from fair to good. Low Intraclass Correlation Coefficients (ICCs) were found for several items from both scales. Outcomes pertaining to criterion validity were mixed. Finally, although we found a positive relationship between scores on the HoNOS and HoNOS-LD and those of the ABCL, the relationships between scores of both HoNOS and HoNOS and the SRZ-P were negative. It is concluded that both HoNOS and HoNOS-LD may be used in clients with mild to borderline ID and that outcomes may depend on the type of rater. The HoNOS-LD may be more suitable for assessing general functioning of clients with mild to borderline ID than the HoNOS.     

Motor performance of children with mild intellectual disability and borderline intellectual functioning

Background There is a relatively small body of research on the motor performance of children with mild intellectual disabilities (MID) and borderline intellectual functioning (BIF). Adequate levels of motor skills may contribute to lifelong enjoyment of physical activity, participation in sports and healthy lifestyles. The present study compares the motor skills of children with intellectual disability (ID) to the abilities observed in typically developing children. It also aimed to determine whether there is an association between degree of ID and motor performance. Methods A total of 170 children between 7 and 12 years old with MID or BIF, who attended schools for special education, were examined on the test component of the Movement Assessment Battery for Children (MABC) test. Both groups were compared with the norm scores of the total score, sub‐scale scores and individual items of the MABC test. Results Of the children, 81.8% with MID and 60.0% with BIF performed below the 16th percentile on the total score of the MABC. Both groups demonstrated a relative weakness in the area of manual dexterity. Comparisons between both groups showed small to moderate effect sizes on the total score of the MABC, as well as for all three sub‐scales, favouring the children with BIF. Conclusions Children with ID had significantly more borderline and definite motor problems than the normative sample and there was an association between degree of ID and performance of manual dexterity, ball skills and balance skills. This study highlights the importance of improving motor skill performance in both children with borderline and mild ID, and the results support the notion that the level of motor and cognitive functioning are related in children with ID.     

Glasgow Anxiety Scale for people with an Intellectual Disability (GAS-ID): development and psychometric properties of a new measure for use with people with mild intellectual disability

Background Self‐rating scales are widely used in general adult practice; however, there is no reliable and valid method for assessing state anxiety in people with intellectual disability (ID). The present study describes the development and psychometric evaluation of a new scale, the Glasgow Anxiety Scale for People with an Intellectual Disability (GAS‐ID). Methods First, an item pool was generated from focus groups, a review of the literature and clinician feedback. Secondly, a draft scale was administered to 19 anxious and 16 non‐anxious people with ID for further validation and appraisal of reliability. Thirdly, the scale was completed by 19 anxious, non‐ID people for cross‐validation with the Beck Anxiety Inventory (BAI). Finally, physiological concomitants were validated by pulse‐oximetry. Results The 27‐item GAS‐ID discriminated anxious from non‐anxious participants, had good test–retest reliability (r = 0.95) and internal consistency (α = 0.96), and was reasonably correlated with the BAI (ρ = 0.75). The correlation between the physiological subscale of the GAS‐ID and changes in pulse rate was moderately significant (ρ = 0.52). Conclusions This preliminary study suggests that the GAS‐ID offers a psychometrically robust and practical (5–10 min) approach to the appraisal of anxiety in this population.     

Annotation: New research into general psychiatric services for adults with intellectual disability and mental illness

Background   There are a variety of models for the mental health care of adults with comorbid intellectual disability (ID) and mental illness. There has been a long-running debate as to whether this should be provided by general psychiatric or specialised ID services. A previous review concluded that there was no clear evidence to support either model with research being often of a poor quality, lacking replication, and outcome measures were often inappropriate or varied between studies. This review aims assess differences in outcome for patients with ID and mental disorders treated in general or specialised ID mental health services.
Method   A literature review was conducted using electronic databases and websites of ID and mental health organisations to locate all references where people with ID receive mental health care in general psychiatric services from 2003. No meta-analysis was attempted because of the divergent nature of the studies.
Results   People with ID (especially severe ID) have reduced access to general psychiatric services. General psychiatric inpatient care is unpopular especially with carers but can be improved by providing specially trained staff and in-reach from community ID teams. Opportunities may exist to enhance the care of people with borderline intellectual functioning within general psychiatric services.
Conclusions   Although no new randomised controlled trials have been published, the weight of research is accumulating to suggest that provision of general psychiatric services without extra help is not sufficient to meet the needs of people with ID.     

Factorial validity and consistency of the Maslach Burnout Inventory among staff working with persons with intellectual disability and dementia

Background Burnout has been considered important to understanding the well‐being of workers in the intellectual disabilities (ID) field and the quality of services delivered to clients/consumers. However, little research has examined the psychometric properties and applicability to staff in ID services of one of the most widely used burnout measurements – the Human Services Survey version of the Maslach Burnout Inventory (MBI‐HSS). Methods Data were gathered using a mailed questionnaire comprising the MBI‐HSS and demographic information. The sample consisted of 435 staff delivering direct care and working in out‐of‐home community placements for persons with ID in New York state. The factorial structure of the scale was examined using confirmatory and exploratory factor analysis. Internal consistency estimates of reliability of the MBI‐HSS were determined using Cronbach's alpha. Results Confirmatory factor analysis supported the MBI‐HSS as an acceptable measure to evaluate burnout in ID services staff. However, the reliability statistics obtained for the Depersonalization (DP) sub‐scale was much lower than what has been reported in studies with other staff populations. An exploratory factor analysis suggested that a four‐factor solution, dividing the DP sub‐scale into two factors, provided a somewhat better fit for the sample. Conclusions The use of the MBI‐HHS as an instrument for measuring burnout among ID workers has its attraction but also its limitations. In particular, the DP sub‐scale should be used with caution because there appear to be wording issues for staff in ID settings that may lead to inconsistent responses.     

The ComFor: an instrument for the indication of augmentative communication in people with autism and intellectual disability

Background The ComFor (Forerunners in Communication) is an instrument to explore underlying competence for augmentative communication. More specifically, it measures perception and sense‐making of non‐transient forms of communication at the levels of presentation and representation. The target group consists primarily of individuals with autism and intellectual disability (ID) without or with only limited verbal communication. The ComFor is suitable for children and adults with a developmental level between 12 and 60 months. This paper describes the theoretical framework and structure of the ComFor, the results of a study on its psychometric properties and its clinical uses. Method The ComFor was tested on a sample of 623 children and adults from the Netherlands and Flanders: a group with autism and ID (n = 310); a group with ID without autism (n = 174); and a control group of typically developing children (n = 139). Results The data generally support the reliability and validity of the ComFor. Internal consistency, inter‐rater and test–retest reliability were found to be good. Construct validity (internal structure, convergent and divergent patterns) was established in different ways. The criterion‐related validity has yet to be established, as predictive data are not available at the moment. Conclusion Taken together, the results indicate that the ComFor is a promising instrument to explore underlying competence for augmentative communication. Areas for future research are outlined and the clinical relevance is discussed.     

Healthcare costs of intellectual disability in the Netherlands: a cost-of-illness perspective

Background Healthcare costs are continuously increasing, and impose a strong responsibility on governments for an adequate allocation of resources among healthcare provisions and patients. Objectives The aims of the present study were to describe the healthcare costs of intellectual disability (ID) and other mental disorders in the context of the total costs of all other diseases, and to determinate the future need of healthcare resources, especially for ID and mental disorders. Methods The present authors performed a top‐down cost‐of‐illness study comprising all healthcare costs of the Netherlands in 1994. Data on healthcare use were obtained for all 22 healthcare sectors, and used to ascribe costs to disease groups, age and sex. Results Costs of mental disorders are by far the largest in the Dutch healthcare system. Some 25.8% of total disease‐specific costs could be ascribed to mental disorders: psychiatric conditions, 10.6%; ID, 9.0%; and dementia, 6.2%. There are large differences between age and sex groups. The costs of ID and schizophrenia are higher among men, and the costs of dementia and depression are higher among women. The age pattern shows two peaks: the first occurs at 25–35 years of age (ID and psychiatric conditions); and the second at 75–85 years of age (dementia). Time trends between 1988 and 1994 show an average annual growth rate of 5.2% for total healthcare costs: psychiatric conditions, 4.8%; ID, 5.4%; and dementia, 9.4%. Demographic projections suggest a less‐than‐average cost increase for ID and psychiatric disorders (with annual growth rates of 0.2% and 0.4%, respectively) compared to the costs of dementia and total healthcare (with annual growth rates of 1.6% and 0.9%, respectively). Conclusions Intellectual disability and mental disorders represent a large part of healthcare use in the Netherlands. The costs will inevitably increase because of the ageing of the population and increasing life expectancy among people with disabilities. Non‐specific cost containment measures may endanger the quality of care for vulnerable people at younger and older ages.     

Feasibility, reliability and validity of the Spanish version of Psychiatric Assessment Schedule for Adults with Developmental Disability: a structured psychiatric interview for intellectual disability

Background Over 30% of people with intellectual disability (ID) have a comorbid psychiatric disorder. However, there are few assessment instruments available for international use and cross‐cultural validation studies of these instruments are rare. The aim of the present study was to standardize the Spanish version of the Psychiatric Assessment Schedule for Adults with Developmental Disability (PAS‐ADD‐10), a semi‐structured interview for people with ID. Methods After a conceptual translation, feasibility (i.e. applicability, acceptability and practicality) and reliability analyses were carried out. The predictive validity of the PAS‐ADD‐10 CATEGO‐5 codings was also examined (i.e. positive and negative predictive values). Four independent raters with wide‐ranging experience in quantitative evaluation and psychiatric assessment of ID evaluated a sample of 80 subjects with ID and borderline intellectual functioning at the AFANAS occupational centre in Jerez, Southern Spain. The ICD‐10 codes were used for psychiatric diagnosis. Results The practicality of the PAS‐ADD‐10 is limited because of the need for previous standardization of SCAN interviews. Nevertheless, its overall feasibility was judged adequate by raters and the PAS‐ADD‐10 was considered extremely useful for training. Test–retest and inter‐rater reliability kappa values were moderate to high. The CATEGO coding showed limited validity because of overdiagnosis of anxiety disorders and underdiagnosis of mood and psychotic disorders (positive predictive value = 74%, negative predictive value = 76%). Conclusions The PAS‐ADD‐10 is a useful tool for standard psychiatric assessment of people with ID; however, CATEGO codings show low validity and a series of modifications should be considered before this instrument is used extensively in Spain. In this regard, a study on the clinical usefulness of the PAS‐ADD‐10 in patients with ID and severe mental disorders has been undertaken.     

Identifying bipolar disorders in individuals with intellectual disability

Objective The aim of the present study was to characterize adults with intellectual disability (ID) and concomitant clinical diagnoses of bipolar disorder (BPD), and determine whether DSM‐IV criteria would distinguish individuals with BPD from patients with other psychiatric diagnoses. Methods A retrospective chart review was done of a convenience sample of adult patients seen over a 3‐year period in a specialty clinic for adults with ID and psychiatric disorders. The DSM‐IV criteria were used to differentiate individuals with clinical symptoms of BPD from groups of patients with other mood or thought disorders with behavioural symptoms which frequently overlap those of BPD. Behavioural symptoms were also catalogued and used to distinguish the diagnostic groups. Results Subjects with clinical symptoms of BPD had significantly more DSM‐IV mood‐related and non‐mood‐related symptoms, as well as functional impairments, compared to individuals with major depression, depression with psychosis or schizophrenia/psychosis NOS (not otherwise specified). Likewise, behavioural profiles of the BPD group of patients differed significantly from patients in the other three groups. Conclusions Bipolar disorder can be readily recognized and distinguished from other behavioural and psychiatric diagnoses in individuals with ID, and DSM‐IV criteria can be useful in the diagnosis of BPD.     

The association between repetitive behaviours, impulsivity and hyperactivity in people with intellectual disability

Background There is a need for assessments of psychological difference and disorder in people who have more severe intellectual disability (ID). Hyperactivity and impulsivity are two behavioural domains of importance as they are correlated with self‐injury and aggression and this alludes to a shared cognitive correlate of compromised behavioural inhibition. Additionally, compromised behavioural inhibition is demonstrably related to repetitive behaviour and the latter might be expected to be associated with impulsivity and hyperactivity. Methods The Activity Questionnaire (TAQ) was developed for this study. Three sub‐scales with high levels of face validity were supported by factor analysis of the scoring of 755 intellectually disabled participants on the TAQ items. These sub‐scales mapped onto the constructs of Overactivity, Impulsivity and Impulsive Speech. Test–retest, inter‐rater reliability and internal consistency were robust. TAQ scores and scores on the Repetitive Behaviour Questionnaire (RBQ) were collected for a sample of 136 participants with varying degrees of ID. Results Scores on the TAQ at sub‐scale and full‐scale level were not related to level of adaptive functioning. There were significant positive associations between overactivity (TAQ) and stereotyped behaviour (RBQ), impulsivity (TAQ) and restricted preferences (RBQ), and impulsive speech (TAQ) and repetitive speech (RBQ). Conclusions The TAQ is a reliable assessment of hyperactivity and impulsivity for people with ID with robust factor structure. Validity requires evaluation. The relationship between impulsivity and restricted preferences may result from a common cognitive impairment in inhibition, which may underpin these two classes of behaviour.     

Comparison of Self- and Proxy Report of Mental Health Symptoms in People With Intellectual Disabilities

Mental illness, and its assessment and treatment, is a concern for caregivers and professionals working with people with intellectual disability (ID), as well as a cause of distress and disability for people with ID. Research in this area is hindered by difficulties associated with recognizing symptoms of mental illness and tracking their changes. The use of empirically derived and tested tools can improve clinical and research outcomes. This study compares proxy reports of mental health symptoms using the Psychiatric Assessment Schedules for Adults with Developmental Disabilities (PAS-ADD) Checklist to self-reported symptoms using an interview form of the Brief Symptom Inventory (BSI). While the two scales were statistically correlated, clinically they presented very differently. The PAS-ADD identified 23.6% of participants as scoring in the at-risk category of mental health symptoms, while self-rating of symptoms on the BSI resulted in 67.8% of participants scoring above the cutoff. Concerns regarding the use of the BSI for a wide range of people with ID are discussed, as well as the concerns of using proxy report for subjective topics such as mental health symptoms.     

Homosexuality among people with a mild intellectual disability: an explorative study on the lived experiences of homosexual people in the Netherlands with a mild intellectual disability

Background Empirical research on homosexuality among people with an intellectual disability (ID) is limited and, to date, very little is known regarding the personal experiences of gay and lesbian people with an ID. This study set out to answer the question: What are the lived experiences of a specific cohort of homosexual people with an intellectual disability living in the Netherlands? Method To answer this question, a qualitative study was performed in which 21 people with a mild ID were interviewed via semi‐structured interviews. In this study, 19 participants were men and two were women (average age = 40.5 years). Results Participants reported positive and negative experiences, and talked about their gay or lesbian identity. Almost half of the participants (n = 10) reported that they had experienced sexual abuse including partner violence (n = 6). Additionally, they indicated that there was a lack of support for homosexual people with an ID. Conclusion Specific problems impact the lives of homosexual people with ID, namely the high prevalence of negative sexual experiences, the lack of support, training and sex education, and their search for a suitable partner.     

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.