Neurodevelopmental disorders and comorbidity in young adults attending a psychiatric outpatient clinic.

"Missed" cases with neurodevelopmental disorders (NDDs) within adult psychiatry services have attracted increasing attention in the last decade. Key questions have been what the prevalence of NDDs (particularly attention-deficit/hyperactivity disorder/ADHD and autism spectrum disorder/ASD) is, and what the clinical and gender characteristics of those with NDD in adult psychiatry are. All first-time attenders at an adult psychiatry clinic serving 18-25 years old were invited to take part in the study regardless of cause of concern. Participation in the study included diagnostic in-depth evaluation performed by experienced adult psychiatrists. Clinical diagnoses (DSM-IV-TR and DSM-5 criteria) were based on all available information (clinical psychiatric interview, clinical observation, and self-rating questionnaires). Almost two thirds (63%) of the study group met criteria for ADHD or ASD. Most of the patients with NDD (particularly the "NDD females") had not been diagnosed in childhood. Twelve percent of the females included had been given an ADHD diagnosis in childhood. In the current study we found that 48% of the females had ADHD. The high male:female NDD ratio reported among children, was not obvious in our NDD group. The results underscore the importance of screening for NDD in adult psychiatric services regardless of referral reason.