The relationship between autism and psychiatric disorders in Intellectually Disabled Adults

Intellectual Disability (ID) shows a high comorbidity with psychiatric disorders with a great variability in the prevalence rates. An important subgroup is represented by subjects with ID and autism or other autistic spectrum disorders (PDD). The purpose of the present study was to assess PDD with specific screening tools in a population of people with ID and compare the groups with or without PDD through the administration of a psychopathological scale in order to verify the differences of psychiatric disorders’ rates. The study was conducted on 90 subjects attending daily centres or residential centres in Florence, Italy. In order to assess the presence of PDD, the PDD-MRS was administrated, while for the assessment of the psychopathological aspects we have used the DASH-II. The presence of a psychiatric disorder has a significant effect on anxiety, depression and organic syndromes and statistically significant differences have been registered in many DASH-II subscales. The statistical comparison between the two groups shows that PDD was clearly correlated with an increased presence of psychiatric disorders. The variable PDD could be considered as a vulnerability factor for psychiatric disorders. However there was still the need to focus on categorical diagnoses, in order to increase our knowledge about the concept of vulnerability in people with ID.     

Psychiatric disorders in individuals with pervasive developmental disorder

Pervasive developmental disorders (PDD) refer to the group of heterogeneous conditions that make up a continuum or spectrum of autistic disorders and share a core triad of impairments consisting of qualitative disturbances in social interaction and verbal and nonverbal communication and imagination. It has long been believed that the prevalence of autism was 2-4 per 10,000 children. However, studies using broader definitions of autistic disorder have suggested that the prevalence of autism spectrum disorder may be as high as 90 per 10,000 and that a greater proportion of individuals with PDD have intellectual levels above 70. Clinicians and researchers have commented on the apparent increase in prevalence of the disorder and have offered a number of explanations, including better recognition and diagnosis of the autism spectrum of disorders and a real increase in the disturbance. It is being increasingly recognized that individuals with PDD are at risk for a wide array of psychiatric disturbances, including affective disorder, anxiety disorders, schizophrenia-like psychosis, aggression, antisocial behavior, and Tourette's disorder (TD). Evidence indicates that PDD is significantly related to the comorbid psychiatric disorders and TD. Because PDD is not rare, individuals with autism spectrum disorder may represent significant subgroups of severely emotionally disturbed patients referred for psychiatric treatment. Because of lack of awareness that the clinical manifestations of PDD are heterogeneous and often mild and that comorbid psychiatric disturbances may obscure the symptoms of the developmental disorder, the diagnosis of PDD may be missed. Implications for practicing clinicians are discussed.     

Validity of the Autism/Pervasive Developmental Disorder Subscale of the Diagnostic Assessment for the Severely Handicapped-II

This study was designed to establish the empirical validity of the Diagnostic Assessment for the Severely Handicapped-II (DASH-II) to screen for the presence of autism in severely and profoundly mentally retarded adults. Participants included 51 individuals residing in a large developmental center in Central Louisiana. The Autism/Pervasive Developmental Disorder subscale of the DASH-II was internally consistent. Additionally, the DASH-II was just as likely as the Childhood Autism Rating Scale (CARS) to classify autistic and control individuals. Specific items on the subscale were examined to identify those items most associated with a diagnosis of autism.     

Self-reported social skills impairment explains elevated autistic traits in individuals with generalized social anxiety disorder

Screening for autism in individuals with generalized social anxiety disorder (GSAD) is complicated by symptom overlap between GSAD and autism spectrum disorder (ASD). We examined the prevalence of self-reported autistic traits within a sample of participants with a diagnosis of GSAD (n = 37) compared to individuals without a GSAD diagnosis (NOSAD; n = 26). Of the GSAD sample participants, 70.84% self-reported autistic traits above a cut-off of 65 on the Autism Quotient-Short (AQ-S) and reported significantly more autistic traits on 3 of 5 AQ-S subscales compared to the NOSAD group. Diagnosis uniquely predicted variation in the social skills subscale above and beyond the other subscales and other predictors. Furthermore, variation in the social skills subscale largely explained group differences on the other subscales. Our results suggest caution in utilizing measures like the AQ-S with clinical populations characterized by social difficulties such as individuals with a GSAD diagnosis.     

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.     

Behavioural characteristics and autistic features in individuals with Cohen Syndrome

Abstract Diagnostic criteria for Cohen Syndrome are based largely on physical characteristics, and systematic information about behaviour and social functioning is limited. Typically, individuals with this condition are described as being very sociable and as showing low rates of pathology. However, recent studies have indicated that behavioural difficulties may occur more frequently than previously suggested and that autistic features may be relatively common. The present investigation of 45 individuals with Cohen Syndrome (age 4–48 years) found that, although 57% of the sample were reported as showing some behavioural disturbance, problems related mainly to anxiety and social interactions; marked anti-social behaviours were rare. Twenty-two individuals met criteria for autism on standardised diagnostic assessments, although the autistic profile was somewhat atypical. The implications of these findings for our understanding of Cohen Syndrome are discussed.     

A retrospective assessment of topiramate in children and adolescents with pervasive developmental disorders

An open-label retrospective study was conducted to assess the effectiveness and tolerability of topiramate in children and adolescents with pervasive developmental disorders (PDD). Topiramate is a novel antiepileptic drug approved as an adjunctive treatment for seizure disorders. A retrospective chart review was conducted in an outpatient clinic specialized in treating individuals with developmental disabilities, to identify all children and adolescents with PDD who received topiramate. Patients were included if concomitant medications remained unchanged. Treatment response was assessed using the Global Improvement item of the Clinical Global Impressions scale (CGI-GI), based on a review of medical records and the Conners Parent Scale (CPS), as completed by parents. Fifteen patients were identified (12 male, 3 female; age = 14.7 +/- 3.3 years), including 11 patients with autistic disorder, 2 patients with Asperger's disorder, and 2 patients with PDD not otherwise specified (PDD, NOS). Eight patients (4 patients with autistic disorder, 2 patients with Asperger's disorder, and 2 patients with PDD, NOS) were judged to be responders, as defined by a score of 1 or 2 on the CGI-GI. Treatment duration was 25 +/- 16 weeks, and the mean dose was 235 +/- 88 mg. Differences between baseline and the end-of-trial period were observed in the following CPS subscales: conduct, hyperactivity, and inattention. No differences were noted in the psychosomatic, learning, and anxiety subscales. Three patients discontinued topiramate because of side effects, with 2 patients experiencing cognitive difficulties and 1 patient a skin rash. Topiramate may be beneficial for treating secondary symptoms of PDD, and prospective openlabel studies and double-blind, placebo-controlled studies to assess its efficacy and safety are needed.     

Autism and Tuberous Sclerosis

Autism and pervasive developmental disorders (PDD) are common in tuberous sclerosis (TSC). The frequency of autism is about 25%, with 40–45% of TSC cases meeting criteria for autism or PDD. Among autistic populations, the frequency of TSC is 1–4% and perhaps as high as 8–14% among the subgroup of autistic individuals with a seizure disorder. Mental retardation (MR) and seizures, particularly infantile spasms, are significant risk factors in the development of autism/PDD in TSC; however, neither are sufficient or necessary for the development of these behaviors. The mechanism underlying the association of autism and TSC is as yet unclear but clinical features and neuroimaging investigations suggest that an abnormal TSC gene may directly influence the development of autism rather than it being a secondary effect of seizures or MR. The presence of autism/PDD may arise if the TSC gene mutations occur at critical stages of neural development in neural tissue of brain regions critical in the development of autism.     

Psychiatric disorder and the broad autism phenotype: evidence from a family study of multiple-incidence autism families

OBJECTIVE: Several studies have shown familial aggregation of some axis I psychiatric disorders in families ascertained through a single autistic proband. In this study the authors examined the rate of axis I psychiatric disorders in nonautistic relatives from multiple-incidence autism families and the possible relationship of these disorders to the broad autism phenotype. METHOD: The rates of axis I psychiatric disorders, assessed by using semistructured and family history interviews, were compared in parents, grandparents, and aunts and uncles ascertained through 25 families of multiple-incidence autism probands and 30 families of probands with Down's syndrome. The possible association between selected psychiatric disorders and the broad autism phenotype, assessed directly through semistructured interviews and observational rating measures, was also examined in the two groups of parents. RESULTS: The parents of the autistic probands had significantly higher rates of major depressive disorder and social phobia than the parents of the Down's syndrome probands. The high rate of depression in the parents of the autistic probands was consistent with the high rates of depression and anxiety detected in the grandparents and aunts and uncles in the autism families by family history. There was no evidence of an association, within individuals, between either depression or social phobia and the broad autism phenotype. CONCLUSIONS: Relatives of autistic individuals have high rates of major depression and social phobia that are not associated with the broad autism phenotype and cannot be explained by the increased stress associated with raising an autistic child. Alternative mechanisms and the scientific and clinical implications of these findings are discussed.     

Depression in Children with Autism/Pervasive Developmental Disorders: A Case-Control Family History Study

Limited information is available about the occurrence of depression in children with autism and other pervasive developmental disorders (PDD). Although depression has been described in autistic children, questions about its validity have often been raised. One approach to address this issue is to investigate family histories of those autistic children diagnosed with clinical depression. Based on data available in nonautistic children, autistic children with depression would be expected to show an increased family history of depression. Since studies of this nature have not been attempted in autistic children, we compared the family history of 13 autistic/PDD children with depression (11 male; 2 female; M full-scale IQ 86.2, SD 24.2; M age 10.4 years, SD 2.2) with 10 autistic/PDD children without a history of current or previous depression (9 male; 1 female; M full-scale IQ 67, SD 12.9; M age 10.5 years, SD 1.6). Diagnosis of depression was based on the DSM-III-R criteria and confirmed independently by two psychiatrists. Ten (77%) of the depressed children had a positive family history of depression compared to 3 (30%) of the nondepressed group, t(21) = –2.4; p = .02. These findings lend support to the validity of depression as a distinct condition in some children with autism/PDD and suggest that, as in the normal population, autistic children who suffer from depression are more likely to have a family history of depression.     

Platelet serotonin,a possible marker for familial autism

Serotonin (5HT) levels in platelet-rich plasma were measured in 5 autistic subjects who had siblings with either autism or pervasive developmental disorder (PDD), 23 autistic subjects without affected siblings, and 10 normal controls. The 5HT levels of autistic subjects with affected siblings were significantly higher than probands without affected siblings, and autistic subjects without affected siblings had 5HT levels significantly higher than controls. Differences in 5HT levels remained significant after adjustment for sex, age, and IQ. These results suggest that 5HT level in autistic subjects may be associated with genetic liability to autism.     

Sex Differences in the Timing of Identification Among Children and Adults with Autism Spectrum Disorders

To examine differences by sex in the timing of identification of individuals with autism spectrum disorders (ASD), survey data were collected in the Netherlands from 2,275 males and females with autistic disorder, Asperger’s syndrome and PDD-NOS. Among participants <18 years of age, females with Asperger’s syndrome were identified later than males. Among participants ≥18 years of age, females with autistic disorder were identified later than males. In more recent years, girls with Asperger’s syndrome are diagnosed later than boys, confirming earlier findings. In adults, the delayed timing of diagnosis in females with autistic disorder may be related to changing practices in diagnosis over time. Strategies for changing clinician behaviour to improve recognition of ASD in females are needed.     

Health communication: A pilot study comparing perceptions of women with and without high functioning autism spectrum disorder

Research indicates significant health disparities for individuals with autism. Insight into characteristic sensory, cognitive, communication, social, emotional, and behavioural challenges that may influence health communication for patients with autism is vital to address potential disparities. Women with high functioning autism spectrum disorder (ASD) may have specific healthcare needs, and are likely to independently represent themselves and others in healthcare. A pilot study compared perceptions of healthcare experiences for women with and without ASD using on-line survey based on characteristics of ASD likely to influence healthcare. Fifty-eight adult female participants (32 with ASD diagnosis, 26 without ASD diagnosis) were recruited on-line from autism support organisations. Perceptions measured included self-reporting of pain and symptoms, healthcare seeking behaviours, the influence of emotional distress, sensory and social anxiety, maternity experiences, and the influence of autistic status disclosure. Results partially support the hypothesis that ASD women experience greater healthcare challenges. Women with ASD reported greater challenges in healthcare anxiety, communication under emotional distress, anxiety relating to waiting rooms, support during pregnancy, and communication during childbirth. Self-disclosure of diagnostic status and lack of ASD awareness by healthcare providers rated as highly problematic. Results offer detailed insight into healthcare communication and disparities for women with ASD.     

Reciprocity in autistic and typically developing children and adolescents with and without mild intellectual disabilities

The assessment of autism in individuals with mild intellectual disabilities (MID) is complicated because of the overlap between autistic traits and intellectual limitations. Impaired social emotional reciprocity is a core diagnostic criterion for autism. However, it is unknown whether reciprocal behaviour differs between MID individuals with or without an autism spectrum disorder (ASD). This study explored differences in reciprocal behaviour of 35 children and adolescents with MID (intelligence quotient 50–85): 15 with ASD (ASD‐MID) and 20 with typical development (TD‐MID) using the Interactive Drawing Test (IDT). ASD‐MID participants showed a lower quality of reciprocal behaviour compared with TD‐MID participants. The difference in quality of reciprocal behaviour between ASD‐MID and TD‐MID participants was not significantly related with Peabody Picture Vocabulary Test scores and thus not attributable to verbal capacity. The IDT is likely to reflect the child's inclination to display reciprocal behaviour in everyday situations, as its scale scores were meaningfully associated with the level of social cognition assessed with the Social Responsiveness Scale. Thus, the IDT seems well suited for measuring impairments in reciprocal behaviour in children and adolescents with MID.     

Autistic social impairment in the siblings of children with pervasive developmental disorders

OBJECTIVE: Sibling recurrence risk in autism has been estimated to be approximately 10%. This study investigated subsyndromal autistic impairments among siblings of probands with pervasive developmental disorders. METHOD: The authors used the Social Responsiveness Scale to obtain quantitative assessments of autistic social impairment in three groups of proband-sibling pairs: 1) autistic children from multiple-incidence families and their closest in age nonautistic brothers (N=49 pairs); 2) children with any pervasive developmental disorder, including autism, and their closest-in-age brothers (N=100 pairs), and 3) children with psychopathology unrelated to autism and their closest-in-age brothers (N=45 pairs). RESULTS: Sibling Social Responsiveness Scale scores were continuously distributed and substantially elevated for both the autistic and pervasive developmental disorder groups. Highest scores (i.e., greatest impairment) were seen among siblings of autistic probands from multiple-incidence families, followed by siblings of probands with any pervasive developmental disorder, then siblings of probands with psychopathology unrelated to autism. CONCLUSIONS: Taken together with previous findings, these results support the notion that genetic susceptibility factors responsible for common, subsyndromal social impairments may be related to the causes of categorically defined pervasive developmental disorders.     

A closer look at the Autism Behavior Checklist: Discriminant validity and factor structure

The psychometric properties of the Autism Behavior Checklist (ABC; Krug, Arick, & Almond, 1980a, 1980b), a 57-item screening checklist for autism was investigated. Professional Informants completed the ABC on 67 autistic and 56 mentally retarded and learning-disabled children. The autistic children were the total population of autistic children aged 6–15 in two circumscribed suburban and rural regions. Using the total score, the ABC accurately discriminated 91% of the children, with 87% of the autistic and 96% of the nonautistic group correctly classified. Moreover, the accuracy of classification was virtually identical when only the more heavily weighted checklist items were used. A 3-factor model accounted for 32% of the total variance in the checklist. Seventeen items loaded.4 or more on Factor 1, 12 items loaded on Factor 2, and 10 items loaded on Factor 3. The present results fail to provide empirical support for a single unidimensional scale for autism. Also, there is little support for subdividing the checklist into five subscales based on symptom areas.This research was supported by grant No. 6603-1202-42 from the National Health Research and Development Program of Health and Welfare Canada to the second author and a Social Sciences and Humanities Research Council of Canada Doctoral Fellowship to the first author. We thank all of the parents and children who have contributed to this research. We also thank Isabel Smith, Julia McInnes, Margaret MacKinnon Doncaster, Mary Clark-Touesnard, Leslie Donovan, and Penny Corkum for data collection.     

Role taking and social competence in autism and mental retardation

Recent data suggest that individuals with autism show deficits in social cognitive abilities when compared with nonautistic persons matched for mental age. These deficits have been proposed as a basis for the social interaction difficulties seen in autistic persons. In the present study, autistic youth were compared with a matched group of nonautistic mentally retarded youth on three role-taking tasks and three measures of social competence. Results indicated that the autistic group was relatively deficient on each of the social competence measures and on one of the role-taking measures. The role-taking measure on which the groups differed also correlated significantly with each of the social competence measures. Results were discussed in terms of the interplay between social cognitive abilities and social interaction.     

The use of the ADI-R as a diagnostic tool in the differential diagnosis of children with infantile autism and children with a receptive language disorder

Children with infantile autism and children with a specific receptive language disorder often show similar behavioural problems, making the differentiation between these two diagnostic categories difficult. The purpose of this study is to evaluate the usefulness of parental information in the differential diagnosis of the two types of disorders mentioned above. Sixteen children with a receptive language disorder and 11 children with infantile autism participated in the study. All children had normal non-verbal IQs. The ADI-R (Autism Diagnostic Interview-Revised) was performed with all children. The results showed that the ADI-R items reflecting behavioural features at pre-school age (age range 4–5 years) were better suited to differentiate the groups than the items reflecting behavioural features at the time of the investigation (mean age: 9 years). The items on the dimension “Reciprocal social interaction” and “Communication and language” discriminated the groups better than the items of the dimension “Restricted interests”. According to the ICD-10 algorithm of the ADI-R one child with autism and one child with a receptive language disorder were falsely classified. These false classifications were mainly due to a distorted parental perception of the child's behaviour. The ADI-R is a useful tool in the differential diagnosis of developmental disorders. Accepted: 27 April 2001     

Mania and behavioral equivalents: A preliminary study

Previous research has failed to address the possibility of behavioral equivalents in people with ID and mania. The relationship between a measure of mania and possible behavioral equivalents was assessed in 693 adults, most with severe or profound ID, living in a large residential setting. The mania subscale of the DASH-II proved to be a homogenous scale, suggesting that this may be a valid measure of mania in individuals with ID. Both item and factor analyses and correlations showed that many behavioral items acceptably correlated with the mania items. There may be some challenging behaviors that are related to mania in individuals with ID. A factor analysis noted a decreased need for sleep, restlessness, agitation, and irritability as items associated with mania.     

Monoamine oxidase activity in blood platelets from autistic children

In order to evaluate the possible abnormality in monoamine oxidase (MAO) activity in early infantile autism, blood platelet samples were obtained from 20 autistic children, aged 2--12 years. MAO activity, measured fluorometrically using serotonin as substrate, was 5.24 +/- 1.65 (Mean +/- Standard Deviation) nM/MG protein/hour in these autistic children. This value was not significantly different from either that in 30 age-matched normal children or that in 39 nonautistic children with various psychiatric and neurological disorders, although autistic children had higher platelet serotonin concentration than these nonautistic individuals.