Volumetric brain abnormalities in adolescents with conduct disorder with and without attention deficit-hyperactivity disorder: a case control study

Background: Conduct disorder (CD) is a prevalent psychiatric disorder in youth with heterogeneous presentations and hazardous outcomes on family and society. Identifying potential biological markers may help in better understanding and management of the problem. This work aims to explore the potential volumetric brain abnormalities in an Arab-Egyptian sample of conduct disordered youth with and without comorbid ADHD. A total of 27 subjects with conduct disorder, 14 of which also fulfilled the criteria of ADHD, in addition to twenty healthy subjects were recruited. A validated Arabic version of the Mini International Neuropsychiatric Interview for Children and Adolescents “M.I.N.I-Kid” was carried out. MRI acquisition was performed on 1.5 T Toshiba MRI scanner. Cortical reconstruction and automatic volumetric segmentation were performed with the Freesurfer image analysis suite. Results: Youth with CD, with and without ADHD, showed significantly lower cortical thicknesses and smaller subcortical volumes in most of the hemispheric areas. When the two patient groups were compared, youth with CD + ADHD had significantly greater cortical thicknesses but smaller subcortical volumes as compared to youth with CD only. Conclusions: Conduct disorder, comorbid with ADHD, might prove to be a distinct phenotypic entity with different biological substrates, and hence different needed management, from CD without comorbid ADHD.