Autism spectrum disorder in adulthood: Diagnostic and training challenges in Greece.

Autism spectrum disorder (ASD) is classified among the neurodevelopmental disorders, which are described in the early chapters of DSM-51 and ICD-11.2 These disorders emerge in childhood, persist across the lifespan, and are characterized by deficits or diversities that affect personal, social, academic, and occupational functioning. Although the two major diagnostic systems have converged in terminology and criteria-with only minor differences in the categorization of co-occurring language and intellectual development disorders-Greece continues to rely on ICD-10, leading to difficulties in the consistent use of terminology among mental health professionals. The global rise in ASD prevalence over recent decades has been widely discussed, largely attributed to broadened diagnostic criteria and increased recognition in groups where autism was previously considered rare, such as women and individuals with milder symptoms. In the United States, current estimates suggest that 1 in 31 children may be diagnosed with ASD.3 In adults, the prevalence is consistently found to be lower. In Greece, the estimated prevalence based on diagnoses recorded by the Diagnostic, Assessment, and Counseling Centers (KEDASY) is 1.15%,4 while no epidemiological data exist for adults. The lifetime cost of care for an individual with autism may exceed 2 million USD.5 The socioeconomic burden in Greece has been exacerbated by the financial crisis, which had a more detrimental impact on families of individuals with autism than the COVID-19 pandemic.6 A critical gap in care has been documented internationally during the transition from adolescence to adulthood. Adults with autism frequently encounter the "double empathy problem," referring to reciprocal difficulties in their communication with neurotypical individuals. This, coupled with the stigma surrounding the diagnosis, often results in misjudgments regarding the abilities and needs of people with autism. Among adults with ASD, depression is the most prevalent and impairing co-occurring psychiatric disorder, often accompanied by anxiety disorders, both of which contribute to marked reductions in functioning, particularly during transitional periods.7-9 For the so-called "lost generation" of adults with autism-those with normal intelligence and relatively functional profiles whose diagnosis was missed earlier-an ASD diagnosis may resolve longstanding diagnostic uncertainty and explain treatment resistance in psychiatric disorders. Management of ASD and psychiatric comorbidities requires individualized treatment planning that integrates psychosocial interventions and targeted, when needed, pharmacological strategies. Multidisciplinary collaboration among professionals is essential, while active family involvement is of fundamental importance.10 In the era of precision medicine, its applicability to ASD depends on a comprehensive understanding of genetic, temperamental, and environmental factors, enabling personalized interventions that may enhance treatment effectiveness and reduce costs. Implementation of such approaches presupposes specialized training of mental health professionals. In Greece, structured training in adult autism for psychiatrists is limited or absent, resulting in delayed or inaccurate diagnoses, reduced access to appropriate services, and inadequate psychiatric care for adults with autism. While the curriculum of child psychiatry specialty provides training for autism in childhood, there is no continuity into adult psychiatry, even though adulthood spans the majority of life. The lack of training contributes to frequent misdiagnoses (particularly among women and individuals from the "lost generation"), inappropriate pharmacological treatments, and the mischaracterization of adults with autism 2 as "non-compliant." Consequently, many individuals with autism and their families are deprived of psychoeducation and necessary support. To address these shortcomings, we propose the integration of a dedicated module on adult ASD into the official psychiatry residency curriculum in Greece, alongside clinical training in autism-specialized services and acquisition of experience in the use of standardized assessment tools. Such measures are essential to improve diagnostic accuracy, ensure continuity of care, and enhance the quality of psychiatric services for adults with autism.