University of Toronto, Toronto, Ontario, Canada.
J Psychiatr Res. 2012 Feb;46(2):226-32. doi: 10.1016/j.jpsychires.2011.10.001. Epub 2011 Oct 22.
Late-life suicide is an under-investigated public health problem. Among the putative vulnerabilities for this complex multifactorial behaviour are deficits in cognitive control, an ability to integrate and prioritize multiple cognitive processes in order to flexibly adapt behaviour and meet situational demands. We investigated cognitive control during rule learning in a complex and changing environment in older individuals with suicide attempts of varying lethality.
Ninety-three participants over the age of 60 (30 healthy controls, 29 depressed never suicidal, 20 low-lethality suicide attempters, 14 high-lethality suicide attempters) underwent structured clinical and cognitive assessments. Participants then completed the Wisconsin Card Sorting Test (WCST), a well-studied task of cognitive control during rule learning.
High-lethality attempters demonstrated a pattern of deficits involving poor conceptual reasoning, perseverative errors and total errors. Compared to low-lethality attempters and healthy controls, high-lethality attempters demonstrated poor conceptual reasoning, as well as increased rates of perseverative errors and total errors. Compared to non-suicidal depressed participants, high-lethality attempters also made more conceptual errors.
High-lethality suicide attempts among older people are associated with impaired cognitive control during rule learning as detected by the WCST. Our data suggest that impairment in cognitive control during rule learning may represent a vulnerability distinct from the impulsive diathesis, typically manifesting in young, low-lethality attempters. This vulnerability may contribute to the high incidence of serious or, often, fatal suicidal acts in old age.
老年人自杀是一个研究不足的公共卫生问题。这种复杂的多因素行为的潜在脆弱性之一是认知控制缺陷，即整合和优先考虑多个认知过程以灵活适应行为和满足情境需求的能力。我们调查了具有不同致命性自杀企图的老年人在复杂和不断变化的环境中进行规则学习时的认知控制。
93 名年龄在 60 岁以上的参与者（30 名健康对照者、29 名无抑郁但从未自杀者、20 名低致命性自杀企图者、14 名高致命性自杀企图者）接受了结构化的临床和认知评估。然后，参与者完成了威斯康星卡片分类测验（WCST），这是一项研究认知控制在规则学习过程中的经典任务。
高致命性企图者表现出一种涉及概念推理能力差、持续错误和总错误的缺陷模式。与低致命性企图者和健康对照组相比，高致命性企图者表现出较差的概念推理能力，以及更高的持续错误和总错误率。与非自杀性抑郁参与者相比，高致命性企图者也犯了更多的概念错误。
老年人的高致命性自杀企图与 WCST 检测到的规则学习中的认知控制受损有关。我们的数据表明，规则学习过程中的认知控制受损可能代表一种不同于冲动素质的脆弱性，这种脆弱性通常在年轻、低致命性企图者中表现出来。这种脆弱性可能导致老年人中严重或经常致命的自杀行为发生率较高。
