Substance Use in Individuals with Mild to Borderline Intellectual Disability: an Exploration of Rates and Risks in the Netherlands

Abstract

Little is known about rates and risk factors of substance use (SU) in individuals with mild to borderline intellectual disabilities (MBID,. This hinders targeted prevention and treatment. In this study we assessed SU rates and risk factors in individuals with MBID in 419 adults (63% male, average IQ = 66) in 16 Dutch disability services. Lifetime and current SU, SU picture recognition, knowledge, attitudes and modeling were assessed with the Substance use and misuse in Intellectual Disability -Questionnaire (SumID-Q). Lifetime licit SU (alcohol and tobacco) was 97%, lifetime illicit SU (predominantly cannabis) was 50%. Current users of tobacco (62%), alcohol (64%), and cannabis (15%) initiated SU at a younger age than those who desisted SU (ps < .001). Participants with mild ID and those with borderline ID did not differ in SU rates (ps .429-.812), or age at SU initiation (ps .221-.853). Current licit SU and lifetime illicit SU were related to male gender, younger age, and (for smoking and stimulant use) to lack of daytime activities. However, these factors did not contribute to multivariate models when recognition, knowledge, attitudes and modeling were added. The models correctly identified current SU in 84% (smoking) and 74% (drinking), and lifetime SU in 76% (cannabis) and 84% (stimulants) of the participants. As almost all participants reported lifetime use of licit, and about half reported lifetime illicit substance use, systematic screening for substance use, and development of preventative and treatment interventions targeted to this group are needed.

Personality dimensions and substance use in individuals with mild to borderline intellectual disabilities

“…To measure lifetime and current alcohol and drugs use, we used the Substance Use and Misuse in Intellectual Disability -Questionnaire (SumID-Q; VanDerNagel, Kiewik, Van Dijk, De Jong, & Didden, 2011;Van Duijvenbode, Didden, Korzilius, Trentelman & Engels, 2013). Substances (i.e., alcohol, cannabis, ecstasy, heroin, cocaine, speed and magic mushrooms) are introduced with images and only if the participant is familiar with a substance further questions about its use are asked.…”

“…Lifetime use was assessed with the item 'Have you ever used alcohol/cannabis/hard drugs?' Response options were: (1) 'no' and (2) 'yes' (VanDerNagel, Kiewik, Van Dijk et al, 2011;Van Duijvenbode et al, 2013). Current substance use was assessed with the item: 'Did you use alcohol/cannabis/hard drugs in the last month?'…”

“…Current substance use was assessed with the item: 'Did you use alcohol/cannabis/hard drugs in the last month?' Response options were (1) 'no' and (2) 'yes' (VanDerNagel, Kiewik, Van Dijk et al, 2011;Van Duijvenbode et al, 2013).…”

Screening for intellectual disabilities: a validation of the Hayes Ability Screening Index for in-patients with substance use disorder

“…Although high rates of substance use have been reported in some studies (van Duijvenbode et al, 2015), the prevalence of substance-related disorders among individuals identified to have ID is estimated to be between 0.5-6% (Cooper et al, 2007;Lin et al, 2016;Slater, 2010a;Sturmey, Reyer, Lee, & Robek, 2003). Studies on substance use typically report that tobacco and alcohol are the most commonly used legal substances and that cannabis is the most commonly used illicit drug (VanDerNagel et al, 2017;vanDuijvenbode et al, 2015).…”

“…There has been a growing recognition that individuals with intellectual disability (ID) may have a comorbid substance use disorder (SUD). During the last ten years, there has been an increase in the body of literature on adapted assessment and treatment of SUD among individuals with ID and borderline intellectual functioning and the understanding and recognition of the special needs of individuals with these dual conditions has improved (Didden, 2017;Kerr, Lawrence, Darbyshire, Middelton, & Fitzsimmons, 2013;VanDerNagel, Kemna, & Didden, 2013;VanDerNagel et al, 2017;van Duijvenbode et al, 2015).…”