Psychiatric conditions and behavioural problems in adolescents with intellectual disabilities: correlates with autism.

OBJECTIVE: To determine whether psychiatric and behavioural disorders occur more frequently in adolescents with autism and intellectual disabilities, compared with those without autism. METHOD: A population-based case-control study was undertaken and 36 adolescents with autism were pairwise matched for age and IQ to 36 adolescents without autism. Caregivers were interviewed with structured psychiatric interview and questionnaire measures of psychiatric and behavioural problems. RESULTS: Compulsive behaviours and stereotypies were significantly more common in adolescents with autism. CONCLUSIONS: Adolescents with autism are prone to compulsive behaviours and stereotypies as well as specific manifestations of anxiety, fears, and phobias.

Gender differences in psychiatric diagnoses among inpatients with and without intellectual disabilities.

There are few published studies on the relationship between gender and psychiatric disorders in individuals with intellectual disabilities. Adults (N = 1,971) with and without intellectual disabilities who received inpatient services for psychiatric diagnosis and clinical issues were examined. Among individuals with intellectual disabilities, women were more likely to have a diagnosis of mood disorder and sexual abuse history; men were more likely to have a substance abuse diagnosis, legal issues, and past destructive behavior. Gender difference patterns found for individuals with intellectual disabilities were similar to those of persons without intellectual disabilities, with the exception of eating disorder and psychotic disorder diagnoses. Gender issues should receive greater attention in intellectual disabilities inpatient care.

Prevalence of autism among adolescents with intellectual disabilities.

OBJECTIVE: To estimate the prevalence of autism in an epidemiologically-derived population of adolescents with intellectual disabilities (ID). METHOD: The prevalence of autism was examined using the Autism Diagnostic Interview-Revised, with appropriate care taken in assessing lower functioning individuals and those with additional physical and sensory impairments. Individual assessment during psychological evaluation, and consensus classification of complex cases, involving clinicians experienced in the assessment of autism, contributed to the identification of autism. RESULTS: Overall, 28% of individuals, or 2.0 of the 7.1/1000 with ID in the target population (as we have previously identified in another study), were identified with autism. Autism rates did not differ significantly across severe ID (32.0%) and mild ID (24.1%); males predominated (2.3 males to 1 female), but less so for severe ID (2 males to 1 female, compared with 2.8 males to 1 female for mild ID). Socioeconomic status did not distinguish the groups with and without autism. Less than one-half of the adolescents who met diagnostic criteria for autism were previously diagnosed as such. CONCLUSIONS: Our overall prevalence estimate for autism is in the higher range of estimates reported in previous studies of ID (more so for mild ID). This likely reflects the changes in diagnostic criteria for autism that have subsequently occurred. Discussion focuses on the identification of autism in the population with ID, and on the implications for service delivery and clinical training.

Inattention, hyperactivity, and impulsivity in teenagers with intellectual disabilities, with and without autism.

OBJECTIVE: To explore inattentive, hyperactive, and impulsive behaviours in teenagers with intellectual disabilities (ID), with and without autism. METHOD: We identified teenagers with ID, with and without autism, in a single geographic area. Those with autism were matched for age, sex, and nonverbal IQ to those with ID only. We compared inattentive, hyperactive, and impulsive (IHI) behaviours in the 2 groups, along with adaptive functioning and medical circumstances. We further subdivided the autism group into those with IHI behaviours (autism IHI) and those without (autism non-IHI) and explored similarities and differences between autism subgroups. RESULTS: As a group, those with autism and ID had more IHI behaviours than those with ID alone. More in the autism group met criteria for attention-deficit hyperactivity disorder and hyperkinetic syndrome. Lifetime exposure to psychotropic medication was greater in the autism group, with stimulant and antipsychotic medications predominating. However, just under one-half of those in the autism group showed no IHI behaviours. Comparison of autism IHI and autism non-IHI groups showed that those with IHI behaviours were significantly more likely to have past (but not current) exposure to stimulant medication. CONCLUSIONS: One in 2 teenagers with ID and coexisting autism displayed clinically significant inattentive, hyperactive, and (or) impulsive behaviours, compared with 1 in 7 of those with ID alone. Most of the remaining teenagers with autism displayed no IHI behaviours. Our results support the need for further investigation into the prevalence and etiology of these IHI behaviours in individuals with autism.

Consensus guidelines for primary health care of adults with developmental disabilities.

OBJECTIVE: To develop practical Canadian guidelines for primary health care providers based on the best available evidence for addressing health issues in adults with developmental disabilities (DD). QUALITY OF EVIDENCE: Authors of background papers synthesized information from their own clinical experience, from consultations with other experts, and from relevant professional publications. Based on discussions of these papers at a colloquium of knowledgeable health care providers, a consensus statement was developed. Standard criteria were used to select guidelines for consideration and to rank evidence supporting them. Most evidence was level III. MAIN MESSAGE: People with DD have complex health issues, some differing from those of the general population. Adequate primary health care is necessary to identify these issues and to prevent morbidity and premature death. Physical, behavioural, and mental health difficulties should be addressed, and primary health care providers should be particularly attentive to the interactions of biological, psychological, and social factors contributing to health, since these interactions can easily be overlooked in adults with DD. Attention must also be paid to such ethical issues as informed consent and avoidance of harm. Developmental disabilities are not grounds for care providers to withhold or to withdraw medically indicated interventions, and decisions concerning such interventions should be based on patients' best interests. CONCLUSION: Implementing the guidelines proposed here would improve the health of adults with DD and minimize disparities in health and health care.

Comparing rates of psychiatric and behavior disorders in adolescents and young adults with severe intellectual disability with and without autism.

Eight males and four females with an Autism Diagnostic Interview-Revised (ADI-R) diagnosis of autism (mean age of 16.3 years) and severe intellectual disability (IQ < 40) were individually matched to controls on the basis of chronological age, gender, and nonverbal IQ. The dependent measure was the Diagnostic Assessment for the Severely Handicapped-II, which is used to screen for psychiatric and behavior disorders in lower-functioning individuals. Participants with autism showed significantly greater disturbances as measured by the Diagnostic Assessment for the Severely Handicapped-II total score and seven of 13 subscales. They also averaged 5.25 clinically significant disturbances compared with 1.25 disturbances for participants without autism. Specific vulnerabilities to anxiety, mood, sleep, organic syndromes, and stereotypies/ tics were found in the participants with comorbid autism.

Attitudes of senior psychiatry residents toward persons with intellectual disabilities.

OBJECTIVES: This study examined the attitudes of senior residents in psychiatry toward persons with intellectual disabilities. Examining residents' attitudes will highlight areas of training that could be enhanced to better prepare psychiatrists to work with individuals with intellectual disabilities. METHOD: A questionnaire was distributed to senior psychiatry residents at a Canada-wide preparatory session for the Royal College of Physicians and Surgeons of Canada. Included in the questionnaire was the Community Living Attitudes Scale Mental Retardation--Short Form (CLAS) as well as demographic items (for example, age, sex, and marital status) and questions about training in intellectual disabilities. Scores on the 4 CLAS subscales (Empowerment, Similarity, Exclusion, and Sheltering) are reported, and analyses of variance were performed to identify factors associated with each subscale score. The residents' scores are compared with those obtained in surveys of other groups. RESULTS: Fifty-eight senior residents from across Canada completed the questionnaire. The residents' scores favored Empowerment and Similarity over Exclusion and Sheltering. Men and women responded differently. Training in intellectual disabilities during residency only appeared to influence the Similarity subscale scores. CONCLUSION: Senior psychiatry residents hold attitudes toward persons with intellectual disabilities that are not entirely consistent with the community living philosophic paradigm. More research is needed to uncover how attitudes of psychiatrists develop, as well as how training can influence attitudes.

Mental retardation in teenagers: prevalence data from the Niagara region, Ontario.

OBJECTIVES: There are few Canadian prevalence studies of mental retardation (MR); those that do exist were conducted prior to the era of community integration. We undertook a population-based study to explore mental health disturbances in young persons with MR. The first requirement was to identify a population with MR and to establish its prevalence. Here, we report data on the prevalence of MR in a population aged 14 to 20 years. METHOD: We conducted the study in the Niagara Region of Ontario, which has a population base of around 400,000. Researchers worked closely with schools and with agencies providing services to persons with MR to identify the study group. We confirmed the functioning level of participants through standard tests of nonverbal intelligence and receptive language; teachers and other service personnel provided information relevant to the estimation of nonparticipants' functioning level. RESULTS: We identified 255 individuals as having MR (IQ < or = 75). Of these, 171 chose to participate (defined as "participants with MR"; the remaining 84 were "nonparticipants with MR"). Thus, the participation rate was 67% (171/255). Participants and nonparticipants with MR did not differ on age, sex, or IQ, although there were more nonparticipants in the lower social strata. Overall prevalence for MR was 7.18/1000. For mild mental retardation (MMR; that is, IQ = 50 to 75), prevalence was 3.54/1000, and for severe mental retardation (SMR; that is, IQ < 50), it was 3.64/1000. CONCLUSIONS: Our prevalence estimate for SMR is similar to rates from previous studies conducted worldwide. Our estimate for MMR parallels the lower rates found in Scandinavian countries and contrasts with the higher rates generally reported in the US.