物质成瘾领域延迟折扣研究中的外部效度问题

The external validity of delay discounting in the field of substance addiction

物质成瘾者的跨期决策缺陷已被大量使用金钱延迟折扣任务的研究所证实。然而近年来,来自金钱延迟折扣任务变式(成瘾物质延迟折扣任务、性延迟折扣任务和跨类别延迟折扣任务)的发现表明,在物质成瘾领域的延迟折扣研究中单一使用金钱延迟折扣任务存在一定的局限性。首先,物质成瘾者对金钱的延迟折扣水平可能并不能完全代表其对成瘾物质、性和其它自然奖赏的延迟折扣水平;其次,仅使用单一延迟折扣任务可能存在对物质成瘾者跨期决策过程的过度简化;最后,金钱延迟折扣任务较其变式对物质成瘾者的一些临床特征不够敏感。未来研究应进一步丰富、拓展物质成瘾领域的跨类别延迟折扣研究,并对可能影响跨期决策的时间因素进行深入探索。

Deficiency in inter-temporal decision making of substance addicts has been consistently confirmed by a lot of studies using monetary Delay Discounting Task.However,the recently emerging evidence from new variants of the monetary Delay Discounting Task(the addictive substance Delay Discounting Task,the Sexual Delay Discounting Task,and the Cross-Commodity Delay Discounting Task)highlighted some limitations in the single use of this paradigm in the delay discounting study of substance addiction,which need to be considered in terms of external validity.In the first place,delay discounting may be a domain-specific concept and the degree of delay discounting towards money may not equal to delay discounting in other aspects of addicts’real life,as a drug,sex,and other natural rewards.Besides this,using Single-Commodity Delay Discounting Tasks may oversimplify the complicated process of inter-temporal decision making,while using paradigms like Cross-Commodity Delay Discounting Tasks may ecologically simulate dilemmas in addicts’daily life.Last but not least,the monetary Delay Discounting Task is less sensitive to some clinical traits of addicts than its variant paradigms,it seems that specific tasks definitely have a better predictive effect on specific facets of inter-temporal decision making cared by different researchers from multiple perspectives.Future studies should further enrich and expand the research of Cross-Commodity Delay Discounting Task in the field of substance addiction to improve external validity,and further,explore the time factors that may affect the process of inter-temporal decision making.