brain structural correlates of intelligence in attention deficit hyperactivity disorder (adhd) individuals

Introduction: neuroimaging evidence has shown the relationship of intelligence with several structural brain properties in normal individuals. however, this relationship with attention deficit hyperactivity disorder (adhd) needs to be investigated. methods: we estimated grey matter (gm) density of the brain using magnetic resonance imaging (mri) scan on 56 adhd individuals, including 30 combined individuals (mean±sd age: 10.44±2.41, intelligence quotient: [iq]=112.13±13.15, male, 24 right hands) and 26 inattentive individuals (mean age =11.39±2.1, iq=107.44±13.98, male, 28 right hands) as well as 30 iq matched healthy control group (mean age=11.08±2.15, iq=115±13.56, male, 23 right hands). results: in this study, two statistical approaches were used. in the first approach, region-based as well as the whole association patterns between full-scale iq and gm were computed and compared between groups. the second approach was to examine the differential pattern of gm density without considering iq in three groups. conclusion: results showed significant differences between the adhd group and the control. this finding could indicate that intelligence is not purely based on the density of gm in certain brain regions; it is a dynamic phenomenon and drastically changes neurodevelopmental disorders.