Kenneth S Kendler1, Henrik Ohlsson1, Jan Sundquist1, Kristina Sundquist1. 1. From the Virginia Institute for Psychiatric and Behavioral Genetics, the Department of Psychiatry, and the Department of Human and Molecular Genetics, Virginia Commonwealth University, Richmond (Kendler); the Center for Primary Health Care Research, Lund University, Malmö, Sweden (Ohlsson, J. Sundquist, K. Sundquist); the Department of Family Medicine and Community Health, Department of Population Health Science and Policy, Icahn School of Medicine at Mount Sinai, New York (J. Sundquist, K. Sundquist); and the Center for Community-Based Healthcare Research and Education, Department of Functional Pathology, School of Medicine, Shimane University, Japan (J. Sundquist, K. Sundquist).
Abstract
OBJECTIVE: The purpose of this study was to determine whether, controlling for genetic effects, drug abuse was transmitted within families as predicted by a contagion model. METHODS: The authors examined 65,006 parent-offspring, sibling, and cousin pairs ascertained from Swedish population registries in which the primary case subject had a drug abuse registration. The rate of drug abuse registration among at-risk secondary case subjects ages 19-23 was studied. Utilizing matched control pairs, a difference-in-difference approach was used to infer causal effects. RESULTS: In offspring, risk for drug abuse registration in the 3 years after an index registration of a parent residing in the same household, neighborhood, or municipality increased 5.9%, 3.4%, and 1.8%, respectively. For siblings of sibling index case subjects, parallel results were 5.9%, 3.9%, and 1.2%. For cousins of cousin index case subjects, excess risk for those in the same neighborhood or municipality was 2.9% and 0.9%, respectively. In all sets of relatives, drug abuse transmission was strongest in male-male pairs and in pairs closest in age. In sibling pairs, stronger transmission was observed in older to younger siblings compared with younger to older siblings. Transmission was stronger within than across the two drug classes with sufficient data (opiates and cannabis). CONCLUSIONS: These results suggest that drug abuse can be transmitted within families by an environmentally mediated temporally defined model of contagion. The most important methodological limitation is that drug abuse registration is an inaccurate measure of the onset of drug abuse. Indeed, as predicted, drug abuse risk increased among potential secondary case subjects in the year before drug abuse registration of the index case subject.
OBJECTIVE: The purpose of this study was to determine whether, controlling for genetic effects, drug abuse was transmitted within families as predicted by a contagion model. METHODS: The authors examined 65,006 parent-offspring, sibling, and cousin pairs ascertained from Swedish population registries in which the primary case subject had a drug abuse registration. The rate of drug abuse registration among at-risk secondary case subjects ages 19-23 was studied. Utilizing matched control pairs, a difference-in-difference approach was used to infer causal effects. RESULTS: In offspring, risk for drug abuse registration in the 3 years after an index registration of a parent residing in the same household, neighborhood, or municipality increased 5.9%, 3.4%, and 1.8%, respectively. For siblings of sibling index case subjects, parallel results were 5.9%, 3.9%, and 1.2%. For cousins of cousin index case subjects, excess risk for those in the same neighborhood or municipality was 2.9% and 0.9%, respectively. In all sets of relatives, drug abuse transmission was strongest in male-male pairs and in pairs closest in age. In sibling pairs, stronger transmission was observed in older to younger siblings compared with younger to older siblings. Transmission was stronger within than across the two drug classes with sufficient data (opiates and cannabis). CONCLUSIONS: These results suggest that drug abuse can be transmitted within families by an environmentally mediated temporally defined model of contagion. The most important methodological limitation is that drug abuse registration is an inaccurate measure of the onset of drug abuse. Indeed, as predicted, drug abuse risk increased among potential secondary case subjects in the year before drug abuse registration of the index case subject.
Entities:
Keywords:
Families; Psychoactive Substance Use Disorder
Authors: Bertha K Madras; Beth Han; Wilson M Compton; Christopher M Jones; Elizabeth I Lopez; Elinore F McCance-Katz Journal: JAMA Netw Open Date: 2019-11-01