I. Carina Gillberg

Background: Long-term consequences of comorbid autism spectrum disorder (ASD) in individuals with anorexia nervosa (AN) are inadequately investigated. Methods: In the 1980s, 51 adolescent-onset AN cases (AN group) and 51 matched controls (COMP group) were recruited from the community. They have been examined on five occasions. The four last assessments included the Morgan-Russell Outcome Assessment Schedule (MROAS) to assess eating disorder outcomes (weight, dieting, menstruation), and related problems including psychiatric, psychosexual and socioeconomic state. In the present study, at age 44, when 30 years had elapsed, MROAS data were compared with previous results. At age 16, 21, 24 and 32 years, all individuals had been assessed regarding ASD. At the 30-year follow-up, the impact of the ASD on the MROAS data was analysed. Results: In the AN group, all core anorectic symptoms (weight, dieting, menstruation) were on a par with the COMP group at the 30-year follow-up, but the positive outcomes were limited to those who had never had an ASD diagnosis. Psychiatric state was significantly worse in the AN group, particularly in the subgroup who had an ASD diagnosis assigned. The AN group—again particularly those with ASD—had a more negative attitude to sexual matters than the COMP group. The AN group had worse outcomes than the COMP group for ‘personal contacts’, ‘social contacts,’ and ‘employment record’ at the 30-year follow-up and the outcomes were worse the more often an ASD diagnosis had been assigned. Limitations: Rare data collection points throughout 30 years (only 5 assessments). ASD was assessed in the first four studies but was not assessed again at the 30-year follow-up. Conclusions: Mental health, psychosexual, and socioeconomic status were compromised up to 30 years after AN onset. Coexisting ASD contributed to the poor outcome. Core anorectic symptoms had “normalised” three decades after AN onset. Plain English summary: Some individuals with anorexia nervosa (AN) also suffer from autism. In this study we have investigated outcome of AN 30 years after the onset of AN and whether the presence of autism affects the outcome. Since the 1980s we have followed 51 individuals with teenage-onset AN and 51 healthy controls. They have been examined on five occasions, and an instrument that measures symptoms of AN (weight, dieting, body image), psychiatric symptoms, ability to work, and relationships with partner, family, and friends has been used to assess outcome. Autism was assessed in the first four studies. Symptoms of AN had normalised at 30-year follow-up, but only among those without autism. Psychiatric symptoms, ability to work, and relationships were issues that persisted after 30 years in the AN group, and those who had both autism and a history of AN had even more pronounced problems in these areas. The AN group had a more negative attitude to sexual matters than the control group, the outcome was worse the more often an autism diagnosis had been assigned. Conclusions: Mental health, psychosexual, and socioeconomic status are affected up to 30 years after AN onset, particularly among those with autism.

The purpose of the study was to evaluate time trends and effects of co-existing autism spectrum disorders (ASD) on outcome in an ongoing long-term follow-up study of anorexia nervosa (AN). The Morgan-Russell Outcome Assessment Schedule (MROAS) was used at 6-, 10- and 18-year follow-up of a representative sample of 51 individuals with teenage-onset AN and a matched group of 51 healthy comparison cases. The full multinomial distribution of responses for the full scale and each of the subscales was evaluated using exact nonparametric statistical methods. The impact of diagnostic stability of ASD on outcome in AN was evaluated in a dose–response model. There were no deaths in either group. Food intake and menstrual pattern were initially poor in the AN group but normalised over time. MROAS ‘mental state’ was much poorer in the AN group and did not improve over time. The psychosexual MROAS domains ‘attitudes’ and ‘aims’ showed persistent problems in the AN group. In the MROAS socioeconomic domain, the subscales ‘personal contacts’, ‘social activities’ and ‘employment record’ all showed highly significant between-group differences at all three follow-ups. A statistically significant negative dose–response relationship was found between a stable diagnosis of ASD over time and the results on the subscales ‘mental state’, ‘psychosexual state’ and ‘socio-economic state’. Outcome of teenage-onset AN is favourable with respect to mortality and persisting eating disorder, but serious problems remain in the domains ‘mental state’, ‘psychosexual function’ and ‘socioeconomic state’. Outcome is considerably worse if ASD is present. Treatment programmes for AN need to be modified so as to accommodate co-existing ASD.

Research into Pathological Demand Avoidance (PDA), which has been suggested to be a subgroup within the Autism Spectrum Disorder (ASD), is almost nonexistent in spite of the frequent reference to the condition in clinical practice. The total population of 15 to 24-year-olds in the Faroe Islands was screened for ASD, and 67 individuals were identified who met diagnostic criteria for ASD (corresponding to a general population prevalence of ASD of almost 1 %). Of these 67, 50 had parents who were interviewed using the Diagnostic Interview for Social and Communication Disorders (DISCO-11) which contains 15 “PDA-specific” items. Nine individuals met criteria for “possible clinical diagnosis of PDA”, meaning that almost one in five of all with ASD also had indications of having had PDA in childhood, and that 0.18 % of the total population had had the combination of ASD and PDA. However, at the time of assessment, only one of the 9 individuals with possible PDA still met “full criteria”. PDA possibly constitutes a considerable minority of all cases with ASD diagnosed in childhood, but criteria for the condition are unlikely to be still met in later adolescence and early adult life.

Vitamin D deficiency has been proposed as a possible risk factor for developing autism spectrum disorder (ASD). 25-Hydroxyvitamin D₃ (25(OH)D₃) levels were examined in a cross-sectional population-based study in the Faroe Islands. The case group consisting of a total population cohort of 40 individuals with ASD (aged 15–24 years) had significantly lower 25(OH)D₃ than their 62 typically-developing siblings and their 77 parents, and also significantly lower than 40 healthy age and gender matched comparisons. There was a trend for males having lower 25(OH)D₃ than females. Effects of age, month/season of birth, IQ, various subcategories of ASD and Autism Diagnostic Observation Schedule score were also investigated, however, no association was found. The very low 25(OH)D₃ in the ASD group suggests some underlying pathogenic mechanism.