Autism in the Faroe Islands: Diagnostic Stability from Childhood to Early Adult Life

Abstract

Childhood autism or autism spectrum disorder (ASD) has been regarded as one of the most stable diagnostic categories applied to young children with psychiatric/developmental disorders. The stability over time of a diagnosis of ASD is theoretically interesting and important for various diagnostic and clinical reasons. We studied the diagnostic stability of ASD from childhood to early adulthood in the Faroe Islands: a total school age population sample (8–17-year-olds) was screened and diagnostically assessed for AD in 2002 and 2009. This paper compares both independent clinical diagnosis and Diagnostic Interview for Social and Communication Disorders (DISCO) algorithm diagnosis at two time points, separated by seven years. The stability of clinical ASD diagnosis was perfect for AD, good for “atypical autism”/PDD-NOS, and less than perfect for Asperger syndrome (AS). Stability of the DISCO algorithm subcategory diagnoses was more variable but still good for AD. Both systems showed excellent stability over the seven-year period for “any ASD” diagnosis, although a number of clear cases had been missed at the original screening in 2002. The findings support the notion that subcategories of ASD should be collapsed into one overarching diagnostic entity with subgrouping achieved on other “non-autism” variables, such as IQ and language levels and overall adaptive functioning.

Asperger syndrome in males over two decades: stability and predictors of diagnosis

“…The studies that Helt and colleagues review have mainly assessed younger children and the fact that our results on adult males are within ranges shown on children adds support for our findings. Other studies on diagnostic stability of ASDs within normal range IQ have had shorter follow‐up times, usually between 1 and 7 years (according to Helt et al., ), and the few studies with longer follow‐up have had fewer cases with normal range IQ (e.g., Howlin & Moss, ; Howlin et al., ; Kocovska et al., ). Our results could therefore be considered to be fairly unique regarding long‐term follow‐up of diagnostic stability in males with AS with normal range IQ.…”

“…There have been more studies made regarding stability of autistic disorder (AD) and PDD-Not Otherwise Specified (PDD-NOS). AD combined with intellectual disability has been shown to be stable in the long-term perspective but there is greater variability when intelligence is within normal range (Billstedt, Gillberg, & Gillberg, 2005;Howlin, Goode, Hutton, & Rutter, 2004;Howlin & Moss, 2012;Kocovska et al, 2013). A recent metaanalysis on the diagnostic stability of AD and PDD-NOS in children (3-10 years of age), reported that approximately 25% of subjects with PDD-NOS move off the autism spectrum when followed up after 1-7 years, compared to 9% of those with AD (Rondeau et al, 2011).…”

Visual scanning during emotion recognition in long‐term recovered anorexia nervosa: An eye‐tracking study

“…Second, we did not have access to a current diagnosis of ASD, and individuals classified as having ASD were required to have been clinically diagnosed with ASD at three or four of the previous examinations (the last follow-up being 12 years before the current study). This procedure is nevertheless justified since autistic traits are relatively stable (Helles, Gillberg, Gillberg, & Billstedt, 2015;Kocovska et al, 2013;Whitehouse, Hickey, & Ronald, 2011) and it is not known to which extent those, and especially women, who lose their clinical diagnosis do so because of learning strategies to compensate for their social and communication difficulties. Women are underdiagnosed and there is an unmet need for better characterization of symptomatology of female adults with ASD.…”

“…This procedure is nevertheless justified since autistic traits are relatively stable(Helles, Gillberg, Gillberg, & Billstedt, 2015;Kocovska et al, 2013;Whitehouse, Hickey, & Ronald, 2011) and it is not known to which extent those, and especially women, who lose their clinical diagnosis do so because of learning strategies to compensate for their social and communication difficulties. First, our sample size was small.…”

Both rare and common genetic variants contribute to autism in the Faroe Islands

“…We previously showed that the prevalence of autism in the Faroe Islands (0.94% of the population (7)(8)(9)) was similar to many other western countries. In this study, we ascertained the genetic profile of 357 individuals including an epidemiological cohort of 36 individuals with autism born between 1985 and 1994 (Fig 1 and S1 Fig), their relatives (n=136) and a group of 185 controls.…”