Autism spectrum disorders have recently encountered a change in how they are perceived, since what used to be a narrowly defined rare disorder of childhood is now recognized as a fairly common heterogeneous disorder, which may receive a first-diagnosis during adolescence and adulthood, yet, a common scenario within this age group is that either the diagnosis is missed or misdiagnosed with other psychiatric disorders. Nevertheless, relatively little has been published about the prevalence of autistic traits in adolescent and young adults, and specifically in those investigated for psychiatric conditions.In the present study, we explore the prevalence of autistic traits among 170 adolescents and young adults who were referred to the outpatient psychiatry clinic “Centro Giovani Ponti” in Milan, Italy between September 2021 and March 2022.

Socio-demographic information was collected and all participants completed the following questionnaires; (1) The Autism Quotient (AQ), (2) The Ritvo Autism Asperger Diagnostic Scale-Revised (RAADS-R), (3) The Sensory Perception Quotient (SPQ) and (4) The Empathy Quotient (EQ).

Out of 170 participants, a striking 103 (60.6%) of the subjects scored above the cut-off in RAADS-R, and 31 (18.2%) of the subjects scored above the cut-off in AQ. Furthermore, 99 (58.2%) participants were in the medium range and 47 (27.6%) were in the low empathy category according to EQ results. A significant sensory sensitivity was measured with an SPQ total score of 55.25 (SD = 17.76). Finally, gender difference was of significance in the RAADS-R, EQ and SPQ, but not in the AQ. In the RAADS-R, non-binary subjects (128.60) scored higher than females (78.68). Whereas, in the SPQ female (57.39) participants scored higher than non-binary subjects (40.30). Furthermore, females scored significantly higher compared to males in the EQ total score with values of 42.56 and 35.89, respectively.

To conclude, we report that a significant proportion of adolescents and young adults seeking psychiatric care have unrecognized autistic traits and that an impact of gender is observed. This so called ‘lost generation’ is attributed to be created by the complex phenotypic presentations, changes in diagnostic criteria and associated diagnostic difficulties. It is of utmost importance to clarify the prevalence of autistic traits within this age range and to increase awareness among clinicians, since establishing the true diagnosis, which is commonly complicated by the high rates of psychiatric comorbidity or overlapping mental health symptoms, will reduce the burden on patients, their families, clinicians, and the society.