Novel approaches to phenotyping drug abuse

Abstract

Available evidence indicates that drug abuse is a complex disorder arising from interplay between underlying genetic susceptibility and environmental risk. Drug abuse is heterogeneous in terms of risk factors, gender distribution and expression, comorbid conditions, types and number of drugs of abuse, symptom expression, and severity. A call for research on novel phenotypes takes on increasing importance in the context of molecular genetic studies where an imprecise case definition will greatly hamper the detection of risk-conferring genes and gene-by-environment interactive effects. Despite the real promise of molecular genetics, there has been limited success in reliably identifying specific susceptibility genes for drug abuse. The individual papers appearing in this issue represent new ways of conceptualizing, measuring, and testing drug abuse phenotypes. They do so by departing from strict reliance on DSM nomenclature, highlighting differences between substance abuse and dependence, using geneticallyinformative approaches to examine familiality or heritability, proposing dynamic phenotypes that capture time and change, and addressing psychiatric comorbidity as a feature of the phenotype. Other papers introduce methodological innovations that hold great promise of expediting progress in investigating phenotypes and their underlying genetic influences. (PsycINFO Database Record (c) 2016 APA, all rights reserved)