禁断状態にあるヘロイン依存症者とそのきょうだいにおける特性様、危険志向、功利主義的な意思決定スタイルの類似点と相違点

Heroin dependence is associated with poor performance on laboratory-based decision-making paradigms. However, it remains unclear whether these deficits may have predated drug abuse due to potential familial susceptibilities or emerged as a consequence of chronic drug use. A family study may help clarify this important issue, so this study was to compare various decision-making aspects between heroin-dependent individuals and their siblings.

A total of 70 abstinent heroin-dependent individuals (HAs), 69 unaffected biological siblings of the HAs (Siblings), and 74 unrelated healthy subjects (HCs) were included and tested on trait-like, risky, and utilitarian decision-making domains, using the Melbourne Decision-Making Questionnaire (MDMQ), the Balloon Analogue Risk Task (BART), and the Moral Decision-Making Task (MDMT).

Data indicated that both HAs and Siblings scored higher on MDMQ Procrastination (Cohen's d = 0.61-1.17), and exhibited higher risk-taking levels (i.e., more pumps per trial and more explosions) on the BART (Cohen's d = 0.39-1.25) compared with HCs. A lower level of competent decision-making (MDMQ Vigilance) and a higher ratio of utilitarian choices in self-involvement dilemmas were found in HAs, but not in Siblings, compared to HCs. Logistic regression models revealed homologous results.

These findings suggest that deficits in trait-like and risk-taking-related decision-making styles are shared by abstinent heroin-dependent individuals and their unaffected siblings, which might represent the conceivable markers for potential familial vulnerabilities implicated in the development of heroin dependence.