Management of endocrine emergencies: joint consensus statement for management of myxoedema coma.

Across adolescence and adulthood, the brain remains highly dynamic, undergoing structural and functional changes that support learning, adaptation, and social development. Neurogenesis continues beyond childhood, with new neurons added in regions such as the hippocampus, and neural circuits reorganising in response to shifting life stages and demands. Particularly, changes in hemispheric organisation have been linked to major life transitions in adulthood, demonstrating that neurobiological development is not confined to early life. These lifelong processes support individuals to adjust to new cognitive, social, and emotional challenges. Adolescence, beginning with puberty and extending until adult roles are assumed, is a particularly dynamic period of neurobiological and social-cognitive change. During this period, young people develop capacities needed to navigate increasingly complex social environments, including peer influence and social evaluation. Perhaps unsurprisingly, this developmental window is also associated with heightened vulnerability to mental health difficulties. Autism is a lifelong neurodevelopmental condition characterised by differences in social communication and the presence of restricted and repetitive behaviours. It is considered to reflect a complex interplay of genetic and environmental factors, with a range of differences in neural functioning identified. As autistic young people move through adolescence and adulthood they may encounter distinct challenges and opportunities that differ from those experienced in early life. Indeed, the myriad social and relational, educational and vocational, and societal and cultural demands of adolescence and adulthood, combined with evidence of ongoing brain plasticity, underscore the importance of studying autism beyond childhood. Despite this, autism research has continued to echo early conceptualisations of autism by focussing on child populations. The autistic community has made clear that a key priority for autism research should be to understand and support autistic needs and differences across the lifespan. Our Collection, presents new research from investigators tackling important questions that relate to autistic adolescents and adults’ lived experiences. These studies reflect ongoing global research efforts to build the knowledge base that can support all members of the autistic community to flourish. The contributions to the Collection span diverse methodologies and questions and it is not possible to highlight them all in this brief Editorial. However, we take this opportunity to focus on three points of convergence across the articles. First, the Collection demonstrates that autistic adolescents and adults may differ from non-autistic peers in underlying bodily and neurophysiological processes, which may then shape behaviour. For example, Cook et al. found gradient differences in the tracing of simple shapes for autistic adults compared to non-autistic adults. These differences were underpinned by differences in speed modulation, which may reflect differences in the bodily filtering of outgoing movement signals. These distinct patterns of speed modulation may be relevant to a broad spectrum of everyday movements including social gestures. Social gestures have relevance to the contribution of Bierlich et al., who measured interpersonal synchrony. Interpersonal synchrony refers to the temporal co-ordination of verbal and non-verbal behaviours between social partners, which associate with a range of positive social outcomes. In their study, which included both autistic and non-autistic adults, differences in interpersonal synchrony were not associated with differences in temporal perception. Bierlich et al. suggest that other processes, such as social attention, multisensory integration or higher order social-cognitive processes, may explain why interpersonal synchrony was attenuated in dyads that included an autistic person. At a more basic physiological level, Ilen et al. measured heart rate variability in autistic adolescents and young adults, alongside self-reported mental health difficulties and momentary assessments of perceived stress and affect. They concluded that increased reactivity to stress may be a mechanism that links altered autonomic functioning, as indicated by heart rate variability, to mental health difficulties. Taken together, this work suggests distinct patterns of sensorimotor behavioural and physiological regulation in autistic adolescents and adults, which may interact with social and emotional functioning.