Heritability of Non-Medical Use of Prescription Drugs among a Sample of Undergraduate Students

Nonmedical use of prescription drugs (NMUPD) has been associated with a number of negative psychological and physical outcomes (e.g., depression, anxiety [Cai et al., 2010], ER visits [Warner et al., 2009], and overdose... [ view full abstract ]

Nonmedical use of prescription drugs (NMUPD) has been associated with a number of negative psychological and physical outcomes (e.g., depression, anxiety [Cai et al., 2010], ER visits [Warner et al., 2009], and overdose deaths, [Becker et al, 2008]). Given its increasing prevalence and associated consequences, NMUPD is a growing public health concern and significant economic burden (Birnbaum et al., 2011; Oderda et al., 2015). Despite the high prevalence, the environmental and genetic contributions to NMUPD remain understudied. Heritability estimates from studies of families and twins suggest moderate heritability; yet, NMUPD is often clustered with other forms of illicit drug use (e.g., heroin) in many analyses. Further, there are no estimates of NMUPD heritability from molecular data. Gene-identification efforts are in their nascent stage. Thus, the present study aimed to utilize molecular genetic methods to understand genetic contributions to NMUPD in a large sample of undergraduate students (N = 7,603, M_age = 18.53, SD = .65; 61.1% female). Lifetime NMUPD, reported by 15.6% of participants, was used as a binary variable in the present analyses and sex was included as a covariate. Preliminary results demonstrated an aggregate SNP heritability estimate of 4.7% (SE = .13) among participants of European ancestry (n = 2,941); however, the estimate did not significantly differ from zero. Genome-wide Complex Trait Analyses (GCTA) in the second largest sub-population, those of African ancestry, did not yield evidence of SNP-based heritability. GWAS are in progress to identify specific genetic variants associated with NMUPD and will also be presented. The present findings should be considered in light of the small sample size. Continued examination of the genetic architecture of NMUPD is important given the potential empirical (gene-findings efforts) and clinical (tailored prevention/intervention programs) implications.