Dopamine Receptor Genetics in Neuropsychiatric Disorders

Abstract

The dopamine system modulates a diverse set of neural functions relevant to neuropsychiatric disorders and is modulated by some drugs used to treat these conditions. As a result, dopamine receptor genes have been a major focus for genetic studies that have analyzed putative associations between polymorphic variants and a wide range of clinical syndromes including alcoholism, substance abuse, schizophrenia, ADHD, anxiety disorders, bipolar and unipolar mood disorders, as well as related traits thought to contribute to these syndromes. In the following chapter, we review the basic genetic organization of the dopamine receptor genes and the evidence for association with these diagnoses. There is considerable inconsistency in the results from these genetic association studies, which is consistent with a complex genetic phenotype, and the neurobiological complexity of behaviors affected in neuropsychiatric illness. Overall, the strongest findings are the associations between variation in the DRD2 gene and alcoholism and the DRD4 gene and ADHD. While these associations do not suggest a major effect on risk in most patients, they do provide important insights into the pathophysiology of these disorders.