Co-occurring Intellectual Disability Research Articles

Characterizing associations between emotion dysregulation, anxiety, and repetitive behaviors in autistic youth with intellectual disability.

There is a paucity of research that explores associations between emotion dysregulation and the expression and severity of core and co-occurring characteristics of autism spectrum disorder (ASD), especially in autistic youth with co-occurring intellectual disability (ID). This study explored the interplay between developmental characteristics and emotion dysregulation, anxiety, and specific subtypes of RRBs that are elevated in autistic youth with co-occurring ID. Generalized additive models demonstrated that age, sex, language level, dysregulation, and anxiety showed unique patterns of association with subtypes of RRBs in a sample of 150 autistic youth with co-occurring ID who are non-speaking or minimally verbal. More specifically, higher anxiety levels were significantly associated with elevations in repetitive sensory motor behaviors (RSMB), self-injurious behaviors (SIB), insistence on sameness (IS), and unusual interests (UI). While emotion dysregulation was a significant predictor of UI, it demonstrated positive, albeit not significant, associations with the intensity of SIB and RSMB. Language level was a significant predictor of RSMB, such that the intensity of RSMB was higher for individuals who were non-speaking relative to those who spoke in single words. These findings provide preliminary insights into patterns of associations between emotion dysregulation, anxiety, and specific subdomains of RRBs in autistic youth with ID.

Racial and ethnic disparities in the co-occurrence of intellectual disability and autism: Impact of incorporating measures of adaptive functioning.

Intellectual disability (ID) commonly co-occurs in children with autism. Although diagnostic criteria for ID require impairments in both cognitive and adaptive functioning, most population-based estimates of the frequency of co-occurring ID in children with autism-including studies of racial and ethnic disparities in co-occurring autism and ID-base the definition of ID solely on cognitive scores. The goal of this analysis was to examine the effect of including both cognitive and adaptive behavior criteria on estimates of co-occurring ID in a well-characterized sample of 2- to 5-year-old children with autism. Participants included 3264 children with research or community diagnoses of autism enrolled in the population-based Study to Explore Early Development (SEED) phases 1-3. Based only on Mullen Scales of Early Learning (MSEL) composite cognitive scores, 62.9% (95% confidence interval [CI]: 61.1, 64.7%) of children with autism were estimated to have co-occurring ID. After incorporating Vineland Adaptive Behavior Scales, Second Edition (VABS-II) composite or domains criteria, co-occurring ID estimates were reduced to 38.0% (95% CI: 36.2, 39.8%) and 45.0% (95% CI: 43.1, 46.9%), respectively. The increased odds of meeting ID criteria observed for non-Hispanic (NH) Black and Hispanic children relative to NH White children when only MSEL criteria were used were substantially reduced, though not eliminated, after incorporating VABS-II criteria and adjusting for selected socioeconomic variables. This study provides evidence for the importance of considering adaptive behavior as well as socioeconomic disadvantage when describing racial and ethnic disparities in co-occurring ID in epidemiologic studies of autism.

Mortality risk among Autistic children and young people: A nationwide birth cohort study.

Existing literature indicates that Autistic people have shorter life expectancy, but little is known about the mortality risk among Autistic children and young people (0-24 years). We used a 15-year nationwide birth cohort study to estimate the mortality risk among Autistic children and young people in Aotearoa/New Zealand. The study included 895,707 children and 11,919 (1.4%) were Autistic. We found that autism was associated with a significantly higher mortality risk compared to the non-Autistic population. In addition, we found that this risk was significantly higher among females compared to males and for those with a co-occurring intellectual disability. Increased efforts are required to better meet the health needs of this population.

A delayed intervention start randomized controlled trial of high- and low-tech communication training approaches for school-age autistic children with co-occurring intellectual disability.

The researchers designed a delayed intervention start randomized controlled trial to compare improvements in functional communication following augmentative and alternative communication (AAC) interventions. The study compared outcomes from function-based applied behavior analytic (ABA) and eclectic non-ABA forms of classroom-based communication strategies (waitlist control) as well as from high- and low-tech forms of AAC. High-tech AAC consisted of tablet-based communication, and low-tech AAC used an exchange of picture cards. The community-based sample consisted of 29 autistic children with a co-occurring intellectual disability. Participants were randomized to groups (AAC, waitlist control), and each group received approximately 3 months of communication intervention. Multilevel modeling of learner outcomes indicated that the function-based approach produced greater improvements than the eclectic alternative, but significant differences were not observed between outcomes of high- and low-tech forms of function-based AAC. These results are consistent with earlier investigations and provide supporting evidence that both high- and low-tech forms of function-based intervention are effective for use with autistic children with accompanying intellectual disability. Additional discussion is provided regarding further research into how technology is applied and incorporated into behavior analytic programming.

Prevalence and Characteristics of Autism Spectrum Disorder Among Children Aged 8 Years - Autism and Developmental Disabilities Monitoring Network, 11 Sites, United States, 2020.

Autism spectrum disorder (ASD). 2020. The Autism and Developmental Disabilities Monitoring (ADDM) Network is an active surveillance program that provides estimates of the prevalence of ASD among children aged 8 years. In 2020, there were 11 ADDM Network sites across the United States (Arizona, Arkansas, California, Georgia, Maryland, Minnesota, Missouri, New Jersey, Tennessee, Utah, and Wisconsin). To ascertain ASD among children aged 8 years, ADDM Network staff review and abstract developmental evaluations and records from community medical and educational service providers. A child met the case definition if their record documented 1) an ASD diagnostic statement in an evaluation, 2) a classification of ASD in special education, or 3) an ASD International Classification of Diseases (ICD) code. For 2020, across all 11 ADDM sites, ASD prevalence per 1,000 children aged 8 years ranged from 23.1 in Maryland to 44.9 in California. The overall ASD prevalence was 27.6 per 1,000 (one in 36) children aged 8 years and was 3.8 times as prevalent among boys as among girls (43.0 versus 11.4). Overall, ASD prevalence was lower among non-Hispanic White children (24.3) and children of two or more races (22.9) than among non-Hispanic Black or African American (Black), Hispanic, and non-Hispanic Asian or Pacific Islander (A/PI) children (29.3, 31.6, and 33.4 respectively). ASD prevalence among non-Hispanic American Indian or Alaska Native (AI/AN) children (26.5) was similar to that of other racial and ethnic groups. ASD prevalence was associated with lower household income at three sites, with no association at the other sites.Across sites, the ASD prevalence per 1,000 children aged 8 years based exclusively on documented ASD diagnostic statements was 20.6 (range=17.1 in Wisconsin to 35.4 in California). Of the 6,245 children who met the ASD case definition, 74.7% had a documented diagnostic statement of ASD, 65.2% had a documented ASD special education classification, 71.6% had a documented ASD ICD code, and 37.4% had all three types of ASD indicators. The median age of earliest known ASD diagnosis was 49 months and ranged from 36 months in California to 59 months in Minnesota.Among the 4,165 (66.7%) children with ASD with information on cognitive ability, 37.9% were classified as having an intellectual disability. Intellectual disability was present among 50.8% of Black, 41.5% of A/PI, 37.8% of two or more races, 34.9% of Hispanic, 34.8% of AI/AN, and 31.8% of White children with ASD. Overall, children with intellectual disability had earlier median ages of ASD diagnosis (43 months) than those without intellectual disability (53 months). For 2020, one in 36 children aged 8 years (approximately 4% of boys and 1% of girls) was estimated to have ASD. These estimates are higher than previous ADDM Network estimates during 2000-2018. For the first time among children aged 8 years, the prevalence of ASD was lower among White children than among other racial and ethnic groups, reversing the direction of racial and ethnic differences in ASD prevalence observed in the past. Black children with ASD were still more likely than White children with ASD to have a co-occurring intellectual disability. The continued increase among children identified with ASD, particularly among non-White children and girls, highlights the need for enhanced infrastructure to provide equitable diagnostic, treatment, and support services for all children with ASD. Similar to previous reporting periods, findings varied considerably across network sites, indicating the need for additional research to understand the nature of such differences and potentially apply successful identification strategies across states.

Young adults with severe physical disabilities

This study aimed to identify factors associated with negative public health care experiences of Finnish young adults with severe physical disabilities with or without a co-occurring intellectual disability after their transition from child to adult health care. Paediatric neurologists used clinical examination Gross Motor Function Classification System (Expanded & Revised) level IV or V to diagnose severe physical disabilities in all 74 subjects (M age 20.2). Thirty-nine of the participants (53%) had a co-occurring intellectual disability according to ICD-10 (IQ < 70). Paediatric neurologists developed the instrument Severely Disabled Youths’ Life Situation and the Functioning of the Service Systems in Finland to collect data. Fisher’s exact tests examined the association between experiences with health care factors and public health care. Binary logistic regressions predicted negative public health care experiences from negative experiences with needing new assistive devices, difficulty getting a physician’s appointment, and physician’s lack of disability knowledge. Multi-professional neurology clinics for young adults with severe physical disabilities and disability education for physicians could improve health care access.

Preterm birth and weight-for-gestational age for risks of autism spectrum disorder and intellectual disability: A nationwide population-based cohort study

To evaluate gestational age (GA) and small-for-gestational age (SGA) as continuums and gender on the incidences of autism spectrum disorder (ASD) and co-occurring intellectual disability (ID). This is a population-based cohort study using the 2004-2008 Taiwan Maternal and Child Health Database. The diagnosis of ASD was determined by International Classification of Diseases, 9th Revision (ICD-9). Generalized estimating equations models were fit to evaluate associations between perinatal variables and ASD. This study included 916,315 individuals. A total of 9474 (1.0%) children were diagnosed with ASD, among whom 1594 (16.8%) had co-occurring ID. Lower GA carried higher odds of ASD with ID (GA < 28 weeks, aOR: 4.26, 95% CI: 2.13, 8.50; GA 28-30 weeks, aOR: 2.80, 95% CI: 1.57, 4.97; GA 31-33 weeks, aOR: 1.63, 95% CI: 1.05, 2.55; GA 34-36 weeks, aOR: 1.39, 95% CI: 1.16, 1.67) and ASD without ID (GA < 28 weeks, aOR:2.05, 95% CI: 1.25, 3.36; GA 28-30 weeks, aOR: 2.02, 95% CI: 1.46, 2.79; GA 31-33 weeks, aOR: 1.42, 95% CI: 1.13, 1.77; GA 34-36 weeks, aOR: 1.18, 95% CI: 1.08, 1.29). Male preterm infants had ASD risks negatively correlated to GA, while ASD risks were significantly increased only among female infants born late preterm. The degree of SGA showed a stepwise increased risk for ASD with and without ID in both male and female infants. Lower GA and the degree of SGA are both associated with ASD susceptibility, either with or without co-occurring ID, and remarkably increased the risk of ID.

The impact of COVID-19 on individuals with ASD in the US: Parent perspectives on social and support concerns.

The COVID-19 pandemic’s disruptions to daily routines and services have proven especially challenging for children with autism spectrum disorder (ASD) and their families. The current retrospective study aimed to determine the impact of the COVID-19 pandemic’s social environmental changes on parental ratings of personal and child concerns about family conflict, opportunities for social interaction, and loss of institutional support (school and therapy services). Analyses of responses from families with ASD in the US determined differences in concerns across three time points which were measured simultaneously: prior to COVID-19, at the start of COVID-19, and at the time of survey completion. From our sample of 246 school-aged children, parents retrospectively reported significantly increasing levels of concern for both themselves and their children over time, with parents’ personal concern levels rated consistently higher than their ratings of their child’s level of concern. Concerns about loss of institutional support were higher for parents of children reported as having co-occurring intellectual disability. Further, parents of younger children also reported more concerns about loss of services, as well as more social concerns. For parent ratings of child concerns, children who were reportedly aware of COVID-19 were determined to have higher levels of social concerns and concerns about loss of institutional support. Meanwhile, the child’s age and gender did not impact their parent ratings of child concerns. The increased level of parental and child-perceived concerns over the course of the pandemic suggests a need for improved service delivery and support for these families. The high levels of concerns observed in the current study provide support for the need to assess families’ priorities and tailor services to best meet families’ needs. This will potentially increase the quality of life of family members, and improve ASD services across the lifespan, and improve outcomes.

Mortality rate, risk factors, and causes of death in people with epilepsy and intellectual disability

PurposeThe extent to which co-occurring intellectual disability influences mortality in people with epilepsy is largely unknown. This study compares mortality rates in people with epilepsy with and without intellectual disability and investigates causes of death and risk factors for mortality. MethodThis retrospective cohort study used linked population-based administrative datasets to derive a cohort of people with epilepsy admitted to hospital from 2005-2015 in New South Wales, Australia. We calculated mortality rates for those with and without intellectual disability and compared them by estimating relative mortality risks with modified Poisson regression. Leading causes of death were summarised. We investigated risk factors for death in people with intellectual disability by fitting Poisson regression. ResultsOf 28500 people hospitalised with an epilepsy diagnosis, 6029 had intellectual disability, 863 (14.3%) of whom died during follow-up. Sex and age-adjusted relative mortality risks showed that people with intellectual disability had higher mortality than those without, with the highest risk in females and peaking at age 5 (males: 1.88, 95%CI 1.28-2.48; females: 2.73, 95%CI 1.84-3.62), then decreasing with age. Neurological, respiratory, and endocrine, nutritional, and metabolic disorders were overrepresented causes of death in people with intellectual disability. The risk factors for death were older age, disability service use and several specific comorbidities. ConclusionChildren and young adults with epilepsy and intellectual disability are at greater risk of dying than those with epilepsy alone. Our data highlight the potential to reduce the excess risk by improved management of epilepsy and comorbid conditions.

Toward better characterization of restricted and unusual interests in youth with autism.

Despite being highly prevalent among people with autism, restricted and unusual interests remain under-researched and poorly understood. This article confirms that restricted interests are very frequent and varied among children and adolescents with autism. It also further extends current knowledge in this area by characterizing the relationship between the presence, number, and type of restricted interests with chronological age, sex, cognitive functioning, and social and communication symptoms.

Unmet health care needs and health care quality in youth with autism spectrum disorder with and without intellectual disability.

The increase in the prevalence of autism spectrum disorder has placed greater demands on the health care system. Children and adolescents with autism spectrum disorder often experience challenges accessing high-quality physical and mental health care due to characteristic social-communication deficits and behavioral difficulties, as well as high rates of complex medical and psychiatric comorbidities. Intellectual disability commonly co-occurs with autism spectrum disorder and individuals affected by this co-occurrence may have additional impairments that compound challenges accessing health care. This study investigated the relations among co-occurring intellectual disability, unmet physical and mental health care needs, and health care quality in a large, nationally distributed sample of youth with autism spectrum disorder using structural equation modeling techniques. Co-occurring intellectual disability was significantly associated with unmet mental health care needs in children with autism. In addition, unmet mental health care needs mediated the relationship between co-occurring intellectual disability and health care quality; youth with autism spectrum disorder and co-occurring intellectual disability who had a past-year unmet mental health need had significantly poorer caregiver-reported health care quality. These findings suggest that youth with autism spectrum disorder and co-occurring intellectual disability may be more likely to experience unmet mental health care needs and receive poorer quality of care than the broader autism spectrum disorder population.

Occupational Therapy-Related Assessments for Adults With Intellectual Disability: A Scoping Review.

Occupational therapy practitioners use structured assessment tools to gather information from adults with intellectual disability (ID) in order to develop the occupational profile, guide occupational therapy intervention, and assess change over time. To identify occupational therapy-related tools in the peer-reviewed literature for use in practice with adults with ID. Peer-reviewed literature published between January 2002 and January 2018 included in CINAHL, PsycINFO, PubMed, and Scopus. Study Selection and Data Collection: The review included articles that had information on occupational therapy-related assessment with adults 18 yr or older who had primary or co-occurring ID. Fifty-eight articles identified 73 occupational therapy-related assessment tools. This scoping review identified a broad range of assessment tools in the occupational therapy domain that are appropriate for adults with ID, some of which may be unfamiliar to occupational therapy practitioners. What This Article Adds: This scoping review provides occupational therapy practitioners with a summary of occupational therapy-related assessment tools for adults with ID and an assessment reference guide.

Co-occurring intellectual disability and autism: Associations with stress, coping, time use, and quality of life in caregivers

BackgroundHaving a child on the autism spectrum (AS) is known to impact caregiver quality of life (QoL), time use, and stress. A co-occurring diagnosis of intellectual disability (ID) is common among children on the autism spectrum, with ID itself impacting caregiver outcomes. MethodThis study sought to understand how co-occurring ID in children on the autism spectrum may influence caregiver-related outcomes. Secondary analysis of survey data from caregivers of 278 children on the autism spectrum with (n = 62) and without (n = 216) co-occurring ID was conducted, exploring impacts on caregiver QoL, stress, coping, and time-use. ResultsUnivariate analysis showed that caregivers of children on the autism spectrum with co-occurring ID reported greater levels of stress due to core symptoms and co-occurring physical conditions, and had different time use patterns then caregivers of children on the autism spectrum without co-occurring ID. Multivariate analysis, however, showed that caregivers of children on the autism spectrum with and without co-occurring ID differed only in the time they spent preparing meals, socialising with friends and accessing in-home respite care. ConclusionsThe presence of co-occurring ID in children on the autism spectrum had limited impacts on caregiver-related outcomes. Families of children across the entire AS require adequate supports.

Self-reported community participation experiences and preferences of autistic adults.

Although participation in communities is a key component of health and well-being, little research has explored community participation among autistic adults. A better understanding of preferences and access to various community activities among autistic adults provides intervention and policy directions in a critical area. This study reports responses from one of the largest groups of autistic adults surveyed to date. Participants reported their valued activities, number of days they participated in each activity during the previous month, and the extent to which they perceived their participation to be sufficient. Grocery shopping was the most common community activity, and most important. A wide range of activities were participated in during the previous month and more than half of the autistic adults reported that most activities were important. Autistic adults with a co-occurring intellectual disability participated in fewer activities and said that fewer activities were important. Sufficiency, or the degree to which an individual felt they participated enough in important activities, was greater for autistic adults with higher incomes and lower for autistic adults who lived independently or had co-occurring psychiatric diagnoses. Breadth of participation, or the number of important types of participation in the past month, was lower for autistic adults residing in supported living facilities and for autistic adults with co-occurring psychiatric diagnoses. Breadth was greater for autistic adults with self-reported service needs. Our study findings offer important information to guide implementation of new federal requirements aimed at promoting greater community participation among individuals covered by Medicaid.

Co-occurring intellectual disability and substance use disorders.

Individuals with intellectual disabilities (ID) are an expanding population that confronts multiple disadvantages from social and environmental determinants of health. Deinstitutionalization and community integration have improved the lives of individuals with ID in many ways. However, deinstitutionalization may increase their access to alcohol and drugs and the potential for developing Substance Abuse Disorders (SUD). It is estimated that 7–8 million people in the United States with an intellectual disability (ID) suffer disproportionately from substance use problems [1]. There is a lack of empirical evidence to inform prevention and treatment efforts in this population and more research needs to be done in order to address these issues.

“Everyone on the Same Team, All Working Together”: Implementing a Co-ordinated Multi-disciplinary Approach to Supporting Young People with Co-occurring Intellectual Disability and Mental Health Issues

ABSTRACT Introduction : Despite the high prevalence of mental health issues for young people with intellectual disability (ID), young people with ID can struggle to receive the mental health support they need. The aim of this study was to examine a new community-based, clinical mental health service for young people (12 −25 years) with co-occurring ID and mental illness, and to explore the outcomes for young people and experiences of families who received service from the new program. Methods : Two studies were conducted using qualitative and quantitative research methods. First, using the Health of the Nations Outcome Scales (HoNOS), a quantitative longitudinal study was conducted to measure any changes in young people’s behavioral and social issues, mental health, and levels of impairment, from the being accepted to the service till the completion of care (n = 23). A second study involved qualitative interviews with parents/carers who attended the service (n = 10) that were analyzed to look for emerging themes in parents’/carers’ experience of the service. Results : Results of study 1 indicated that young people’s behavioral issues and social problems decreased from the time of admission to their completion of carer. Further, results of Study 2 revealed that parents/carers considered the mental health and behavior of their child had improved from being in the program. Parents also valued the person-centered, multidisciplinary, co-ordinated approach of the service, and viewed the new program as an improvement on previous services they had experienced. Conclusions : This study provides preliminary support for the efficacy of the new program and suggests future specialist dual disability services may look to a family-focused, multidisciplinary approach that includes assessment, treatment, and management as an effective treatment model.

Autism in the Western Cape province of South Africa: Rates, socio-demographics, disability and educational characteristics in one million school children

The prevalence of autism spectrum disorder in South Africa is unknown and, to date, very little research has been performed within school systems that could inform the rates, distribution and profile of needs of children with autism spectrum disorder in education. We performed a comprehensive database search of all children with autism spectrum disorder in the formal education system in the Western Cape province of South Africa and compared the findings with population demographic expectations of the province. From a population of 1,154,353 children attending schools in the province, a total of 940 children with a diagnosis of autism spectrum disorder were identified, representing a rate of 0.08%. The male: female ratio was 5.5:1. There was a significant difference in the self-reported racial and language composition of the autism spectrum disorder sample compared with the Western Cape demographics where a higher proportion of children with autism spectrum disorder were from White racial groups and English-speaking homes. Eighty-nine percent of children with autism spectrum disorder were in Special Schools and only 10% were in Ordinary/Mainstream Schools. Most of the children (83%) attended schools in the City of Cape Town and only 17% in rural areas. Co-occurring intellectual disability was reported in 22.2% of the population, attention-deficit/hyperactivity disorder in 2.6% and epilepsy in 0.7%. Data showed a 76.03% increase in autism spectrum disorder in schools between 2012 and 2016, with an average increase of 15.18% per year. Findings suggested an under-representation of autism spectrum disorder in schools and an under-identification of co-occurring conditions. Results indicate that despite being one of the better-resourced provinces in South Africa, the Western Cape is not equipped to identify and meet the culturally and linguistically diverse needs of its communities. We propose strengthening of educational systems for children with autism spectrum disorder in the Western Cape, and similar investigations in other South African provinces. Lay abstract There is very little information about autism spectrum disorder in South Africa and not much is known about children with autism spectrum disorder and their educational needs. In this study, we searched for all children with autism spectrum disorder attending schools in the Western Cape province of South Africa and compared our findings with the profile of people living in the province. We found fewer children with autism spectrum disorder in schools than expected (0.08%) and co-occurring conditions (intellectual disability = 22.2%, attention-deficit/hyperactivity disorder = 2.6% and epilepsy = 0.7%) were reported at lower rates. More children were from White racial groups and from English-speaking homes compared with the Western Cape population demographics. Most of the children (89%) attended schools for children with Special Educational Needs and only 10% were in Ordinary/Mainstream schools. Eighty-three percent attended schools in urban areas and 17% in rural areas. There was a 76.03% increase in children with autism spectrum disorder in schools between 2012 and 2016. Our findings support the need for better identification and reporting of children with autism spectrum disorder in the education system. We propose urgent review and strengthening of education systems for children with autism spectrum disorder in the Western Cape province and in other parts of South Africa.

Transition preparation activities and expectations for the transition to adulthood among parents of autistic youth

BackgroundParents of autistic youth are highly involved in the transition preparation process, yet the role and influence of parental factors and perceptions is underexplored. In the current study, we aimed to expand understanding of transition preparation and the role and influence of parental factors for autistic youth including perceptions of the likelihood (i.e., parent expectations), importance, and parental influence over postsecondary outcomes as well as parental self-efficacy, parent stress, and parent concerns for the future. MethodWe surveyed 269 parents of autistic youth (ages 14–21, 78.2 % male) who did not have co-occurring intellectual disability. We used linear regression analyses to examine youth and parent predictors of the frequency of transition preparation activities, parents’ overall sense of preparation, and parental worry about the future. We also qualitatively analyzed open-ended responses about parent concerns. ResultsThe most frequently endorsed transition preparation activities were discussions about the future and chores. Parental factors were associated with greater frequency of transition preparation activities, greater overall sense of preparation for the transition, and less overall worry. Key areas of parent concern were related to youth independence, social life, employment/finances, autism features, safety, happiness, and health. ConclusionsThe results of this study have implications for education and interventions focused on supporting autistic youth and their parents for the transition to adulthood. There is a need for transition-related interventions that focus on parents and on particular instruction for raising expectations, enhancing parent self-efficacy, and increasing parental sense of control over outcomes.

Suicidal Ideation and Self-inflicted Injury in Medicare Enrolled Autistic Adults With and Without Co-occurring Intellectual Disability.

Suicidality is significantly more common in autistic adults than the general population, yet the factors that increase risk for suicidality among autistic adults remain largely unknown. We identified characteristics associated with suicidal ideation and suicide attempts/self-inflicted injury in a U.S. national sample of Medicare-enrolled autistic adults. We conducted a case-control study of autistic adults aged 18-59years (n = 21,792). Younger age, white race, depression disorders, and psychiatric healthcare utilization were associated with increased odds of suicidal ideation and suicide attempts. Co-occurring intellectual disability was associated with significantly greater odds of a suicide attempt, but lower odds of suicidal ideation. Findings underscore the need for improved methods to identify ideation prior to attempt among adults with autism and intellectual disability.

The Association of Paternal IQ With Autism Spectrum Disorders and Its Comorbidities: A Population-Based Cohort Study

Original case descriptions of autism noted that parents of the affected children tended to be highly educated and intelligent, a characterization that has endured publicly. Recent genetic studies indicate that risk for autism spectrum disorders (ASD) is associated with high intelligence. We examined the association between paternal intelligence and ASD, considering co-occurring intellectual disability (ID) and attention-deficit/hyperactivity disorder (ADHD). We used a register-based cohort study design including 360,151 individuals with fathers conscripted to the Swedish military, resident in Stockholm, Sweden, born from 1984 to 2008, and followed until December 31, 2011, for diagnosis of ASD, ADHD, and/or ID. Risk of neurodevelopmental disorders relative to paternal IQ (rated on a 9-point scale) was assessed using a score of 5 (average intelligence) as the referent in models accounting for potentially nonlinear relationships and clustering of siblings. We observed an association between high paternal IQ and offspring risk of ASD without ID/ADHD in models adjusted for individual and family characteristics (ORIQ=9 1.32, 95% CI 1.15-1.52), an association that appeared to be driven largely by the fathers' score on the technical comprehension portion of the test (ORTechnical IQ= 9 1.53, 95% CI 1.31-1.78). Conversely, low paternal IQ was associated with ASD+ID (ORIQ= 11.78, 95% CI 1.27-2.49) and ASD+ADHD (ORIQ= 11.40, 95% CI 1.16-1.70); low paternal IQ was strongly associated with ID (ORIQ= 1 4.46, 95% CI 3.62-5.49) and present also for ADHD (ORIQ= 11.56, 95% CI 1.42-1.72)] without co-occurring ASD or ID. The relationship between paternal IQ and offspring risk of ASD was nonmonotonic and varied by the presence of co-occurring disorders, probably reflecting phenotypic diversity among affected individuals.