Newswise — Alcohol use disorder (AUD) often co-occurs with chronic pain (CP), yet the relationship between the two is complex – involving genetic, neurophysiological, and behavioral elements – and is poorly understood. This review addressed the genetic influences on brain reward and stress systems that neurological research suggests may contribute to the co-occurrence of AUD and CP.
Candidate gene association studies (CGAS) and genome-wide association studies (GWAS) have provided initial evidence suggesting that a similar dysregulation of reward and stress pathways contribute to AUD and CP, and that genetic influences on these pathways may contribute to both conditions. More specifically, genetic association studies that have looked at AUD and CP independently have identified a number of single-nucleotide polymorphisms (SNPs) – DNA sequence variations – suggestively associated with AUD and CP, with several of these SNPs being located in or near a common set of genes. These common genes are either directly or indirectly related to the reward and stress systems, and are also more broadly involved with the central nervous system (CNS).
The authors suggested that these results must be interpreted with caution until studies with sufficient statistical power are conducted and replicated. Further, the co-occurrence of AUD and CP reflect a common genetic basis that will likely involve CNS processes other than reward and stress mechanisms in AUD-CP co-occurrence. As the field of molecular genetics continues to advance, if such shared genetic contributions to AUD and CP may be identified, this knowledge can help inform understanding of the underlying mechanisms that contribute to the etiologies of each disorder and their co-occurrence. This would refine and improve the diagnosis and treatment of AUD and CP.