Developmental trajectories of autistic social traits in the general population

Abstract

Background Autistic people show diverse trajectories of autistic traits over time, a phenomenon labelled ‘chronogeneity’. For example, some show a decrease in symptoms, whilst others experience an intensification of difficulties. Autism spectrum disorder (ASD) is a dimensional condition, representing one end of a trait continuum that extends throughout the population. To date, no studies have investigated chronogeneity across the full range of autistic traits. We investigated the nature and clinical significance of autism trait chronogeneity in a large, general population sample. Methods Autistic social/communication traits (ASTs) were measured in the Avon Longitudinal Study of Parents and Children using the Social and Communication Disorders Checklist (SCDC) at ages 7, 10, 13 and 16 (N = 9744). We used Growth Mixture Modelling (GMM) to identify groups defined by their AST trajectories. Measures of ASD diagnosis, sex, IQ and mental health (internalising and externalising) were used to investigate external validity of the derived trajectory groups. Results The selected GMM model identified four AST trajectory groups: (i) Persistent High (2.3% of sample), (ii) Persistent Low (83.5%), (iii) Increasing (7.3%) and (iv) Decreasing (6.9%) trajectories. The Increasing group, in which females were a slight majority (53.2%), showed dramatic increases in SCDC scores during adolescence, accompanied by escalating internalising and externalising difficulties. Two-thirds (63.6%) of the Decreasing group were male. Conclusions Clinicians should note that for some young people autism-trait-like social difficulties first emerge during adolescence accompanied by problems with mood, anxiety, conduct and attention. A converse, majority-male group shows decreasing social difficulties during adolescence.

Mental health and social difficulties of late‐diagnosed autistic children, across childhood and adolescence

“…This increase during childhood and adolescence fits with findings in a different birth cohort, which identified a group of young people who show a marked escalation of autistic social difficulties in late childhood and early adolescence (Mandy, Pellicano, Pourcain, Skuse, & Heron, 2018;Pender, Fearon, St Pourcain, Heron, & Mandy, 2021;Riglin et al, 2021). In these studies, girls are over-represented amongst those showing this apparent escalation of autistic social difficulties (Mandy et al, 2018;Pender et al, 2021). In our analyses, sex did not moderate the association between diagnostic timing and EBSD change over time: within each group, boys and girls showed similar EBSD trajectories.…”

“…In the first two waves of assessment (i.e., 3 and 5 years), the mean score for this group was in the average range but, by the age of 14, their average score was in the abnormal range, and exceeded that of the earlier-diagnosed group. This increase during childhood and adolescence fits with findings in a different birth cohort, which identified a group of young people who show a marked escalation of autistic social difficulties in late childhood and early adolescence (Mandy, Pellicano, Pourcain, Skuse, & Heron, 2018;Pender, Fearon, St Pourcain, Heron, & Mandy, 2021;Riglin et al, 2021). In these studies, girls are over-represented amongst those showing this apparent escalation of autistic social difficulties (Mandy et al, 2018;Pender et al, 2021).…”

Childhood diagnoses in individuals identified as autistics in adulthood

“…Another explanation for adult autism diagnoses with no apparent psychiatric problems in childhood is that some individuals simply develop autism symptoms later than in the traditional developmental trajectory of autism. In a large general population longitudinal cohort, a subgroup consisting of 7.3% of the cohort was found to have autistic traits that increased over time, particularly during the 10–16-year age period [ 32 ]. This could suggest that these individuals develop a late-onset variant of autism.…”

“…In other words, their symptoms might have a resemblance with autism, but the aetiology and neurological underpinnings may well be different. Studies finding evidence of late-onset autistic traits [ 32 , 33 ] are generally based on instruments such as the social and communication disorders checklist (SCDC) that measure “autistic social traits”, which do not cover all aspects of autism symptoms. Although they measure traits that have been found to be elevated in individuals with autism, the inverse claim, i.e.…”

Towards equitable diagnoses for autism and attention-deficit/hyperactivity disorder across sexes and genders

“…In the general population, gendered role expectation and interpersonal complexity substantially increase in adolescence, especially for girls/women, translating into steeper increase of social-communication challenges over teenage years in girls/ women than boys/men [70,71]. In this context, some autistic youth, especially girls/women, may eventually show clinical needs for autism diagnosis at an older age as the demands exceed their capacity.…”