Attention deficit hyperactivity disorder (
ADHD) has increasing evidence for the role of
neurohormones in its etiopathogenesis. It has been suggested that the effects of
neurosteroids on the brain in the early developmental period may predispose to neurodevelopmental pathologies. In our study, we examined serum
dehydroepiandrosterone (
DHEA),
dehydroepiandrosterone sulfate (
DHEA-S), and
allopregnanolone levels in children with
ADHD and whether these
neurosteroids differ in the presence of
specific learning disorder (SLD) and
oppositional defiant disorder (ODD) comorbidities (ADHD+SLD and ADHD+ODD). We also investigated the relationship between
neurosteroid levels and the severity of
ADHD symptoms. Thirty-five prepubertal children with
ADHD and 33 prepubertal healthy children, all aged 6-10 years, were included in this study. The severity of
ADHD symptoms was assessed with the parent-rated and teacher-rated Turgay DSM-IV Disruptive Behavior Disorders Rating Scale (T-DSM-IV-S). Serum
allopregnanolone levels were significantly lower in the
ADHD group compared to healthy controls. When analyzed according to comorbidity status, serum
allopregnanolone levels were lower in ADHD+SLD and ADHD+ODD groups compared to healthy controls. However, when compared to healthy children, serum
DHEA and
DHEA-S levels in children with
ADHD were not significantly different. Serum
allopregnanolone levels were negatively associated with teacher-rated T-DSM-IV-S hyperactivity/impulsivity scores for all participants only. These findings suggest that
allopregnanolone may play a role in the pathophysiology of
ADHD, especially in the presence of ODD and SLD comorbidities.