Moderator Effects of Working Memory on Symptom Stability in Attention-Deficit/Hyperactivity Disorder by Dopamine D1 and D2 Receptor Polymorphisms During Development
Date of Degree
Jeffrey M. Halperin
Background: Developmental changes in dopaminergic pathways in the prefrontal cortex (PFC) that are important for working memory have been hypothesized to play a central role in the trajectory of attention-deficit/hyperactivity disorder (ADHD), but not the initial onset of the disorder. This dissertation research examines whether dopamine receptor D1 (DRD1) and dopamine receptor D2 (DRD2) gene polymorphisms moderate the association between improvements in working memory and declines in attention problems in ADHD from childhood to adolescence/young adulthood. Methods: Participants were 76 racially/ethnically diverse youth diagnosed with ADHD in childhood and followed prospectively for almost 10 years. Stability of ADHD symptomatology was measured as a quantitative trait using the Attention Problems scale from the Child Behavior Checklist collected both in childhood and adolescence/young adulthood. Digit Span Forward and Digit Span Backward were administered at both time points to assess working memory maintenance and manipulation, respectively. Genotype and age were moderator variables. Results: DRD1 and DRD2 polymorphisms were associated with the stability of attention problems in adolescence/young adulthood, but not childhood. DRD1 polymorphisms, but not DRD2, significantly moderated the association between working memory and attention problems, with the strongest effects evidenced during adolescence/young adulthood. Notably, DRD1 moderation of working memory on attention problems was specific to manipulation performance. Conclusions: Attention problems decreased over the course of almost 10 years if manipulation concomitantly improved during this period of development in a subgroup of individuals with childhood-diagnosed ADHD depending on their genetic makeup.
Trampush, Joey W., "Moderator Effects of Working Memory on Symptom Stability in Attention-Deficit/Hyperactivity Disorder by Dopamine D1 and D2 Receptor Polymorphisms During Development" (2010). CUNY Academic Works.