Retinol Binding Protein-4, Orexin-A, and adiponectin levels in patients diagnosed with attention deficit and hyperactivity disorder and cognitive dissociation syndrome

Attention-Deficit/Hyperactivity Disorder (ADHD), defined as inattentive, hyperactive/impulsive, or combined type, is the most commonly observed neurodevelopmental disorder in childhood. Meta-analyses on ADHD have reported a global prevalence ranging between %5.29 and %7.1. In recent years, Cognitive Disengagement Syndrome (CDS), characterized by symptoms such as daydreaming, staring blankly, appearing drowsy, moving slowly, and inattention, has been identified as a distinct clinical profile. Despite ongoing research on ADHD and CDS, no diagnostic biomarker has yet been established. The aim of this study is to compare the levels of Retinol-Binding Protein-4 (RBP-4), Orexin-A, and Adipsin among children and adolescents diagnosed with CDS, those diagnosed with ADHD, and healthy controls. The study included a total of 85 children and adolescents aged 6–18 years, who were either diagnosed with CDS or ADHD or were healthy controls, all of whom voluntarily participated and were recruited from the Child and Adolescent Psychiatry outpatient clinic at Akdeniz University Faculty of Medicine. The mean age of participants diagnosed with CDS was 12.172 ± 2.86, those with ADHD was 10.5 ± 2.71, and the control group was 11.642 ± 2.93. In our findings, Orexin-A levels were lower in both CDS and ADHD groups compared to the control group. Among those with ADHD who also exhibited symptoms of conduct disorder, Orexin-A levels were found to be elevated. Adipsin levels in CDS group were higher than those in both ADHD and control groups. There was no statistically significant difference in RBP-4 levels among CDS, ADHD, and control groups. Consistent with the literature, Orexin-A levels were lower in individuals with ADHD. Orexin-A, primarily synthesized in the hypothalamus and involved in the regulation of the sleep-wake cycle, physical activity, and appetite, has also been detected in various regions of the cerebral cortex and cerebellum. Similarly, Orexin-A levels in CDS group were found to be lower than those of control group. In addition, Adipsin levels were elevated in CDS group. Although some studies have noted an association between Adipsin and autoimmunity, no prior research has examined this in relation to ADHD or CDS. No significant differences were found regarding RBP-4 levels in either clinical group. To the best of our knowledge, this is first biomarker study comparing CDS and ADHD groups. However, larger sample sizes and randomized controlled trials are needed to confirm these findings and to establish biomarker validity. Within this context, our study serves as a preliminary contribution to the literature. Keywords: ADHD, CDS, Adipsin, Orexin-A, RBP-4