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Objective-Suicide rates are very high in old age, and the contribution of cognitive risk factors remains poorly understood. Suicide may be viewed as an outcome of an altered decision process. We hypothesized that impairment in a component of affective decision-making -reward/ punishment-based learning -is associated with attempted suicide in late-life depression. We expected that suicide attempters would discount past reward/punishment history, focusing excessively on the most recent rewards and punishments. Further, we hypothesized that this impairment could be dissociated from executive abilities such as forward planning.Method-We assessed reward/punishment-based learning using the Probabilistic Reversal Learning task in 65 individuals aged 60 and older: suicide attempters, suicide ideators, nonsuicidal depressed elderly, and non-depressed controls. We used a reinforcement learning computational model to decompose reward/punishment processing over time. The Stockings of Cambridge test served as a control measure of executive function.Results-Suicide attempters but not suicide ideators showed impaired probabilistic reversal learning compared to both non-suicidal depressed elderly and to non-depressed controls, after controlling for effects of education, global cognitive function, and substance use. Model-based analyses revealed that suicide attempters discounted previous history to a higher degree, compared to controls, basing their choice largely on reward/punishment received on the last trial. Groups did not differ in their performance on the Stockings of Cambridge.Conclusions-Older suicide attempters display impaired reward/punishment-based learning. We propose a hypothesis that older suicide attempters make overly present-focused decisions, ignoring past experiences. Modification of this 'myopia for the past' may have therapeutic potential.Please address correspondence to: Dr. Katalin Szanto, Western Psychiatric Institute and Clinic, 100 N Bellefield Ave, Pittsburgh, Pennsylvania 15213. Phone: 412-586-9601; szantok@upmc.edu. All authors report no competing interests. NIH Public Access Author ManuscriptAm J Psychiatry. Author manuscript; available in PMC 2011 January 13. Worldwide, suicide is more common in the elderly than in any other age group (1). Suicide attempts in late life are more lethal than in mid-life (2), with up to one-half ending in death in older men (3). Though cognitive decline is prevalent in old age and may contribute to the heightened suicide risk, little is known about the role of cognitive factors. Initial evidence links late-life suicidal behavior to poor performance on screening measures of cognitive control (4,5).Evidence from younger suicide attempters indicates impaired performance on tests of cognitive control (6-9) and poor problem-solving (10). To the extent that findings from younger adults generalize to late-life suicide, they suggest a deficit in cognitive abilities relevant to dealing with life's problems and making decisions. Yet, cognitive mechanisms that underpin...

Reinforcement learning describes motivated behavior in terms of two abstract signals. The representation of discrepancies between expected and actual rewards/punishments – prediction error – is thought to update the expected value of actions and predictive stimuli. Electrophysiological and lesion studies suggest that mesostriatal prediction error signals control behavior through synaptic modification of cortico-striato-thalamic networks. Signals in the ventromedial prefrontal and orbitofrontal cortex are implicated in representing expected value. To obtain unbiased maps of these representations in the human brain, we performed a meta-analysis of functional magnetic resonance imaging studies that employed algorithmic reinforcement learning models, across a variety of experimental paradigms. We found that the ventral striatum (medial and lateral) and midbrain/thalamus represented reward prediction errors, consistent with animal studies. Prediction error signals were also seen in the frontal operculum/insula, particularly for social rewards. In Pavlovian studies, striatal prediction error signals extended into the amygdala, while instrumental tasks engaged the caudate. Prediction error maps were sensitive to the model-fitting procedure (fixed or individually-estimated) and to the extent of spatial smoothing. A correlate of expected value was found in a posterior region of the ventromedial prefrontal cortex, caudal and medial to the orbitofrontal regions identified in animal studies. These findings highlight a reproducible motif of reinforcement learning in the cortico-striatal loops and identify methodological dimensions that may influence the reproducibility of activation patterns across studies.

Background-The decision to commit suicide may be impulsive, but lethal suicidal acts often involve planning and forethought. People who attempt suicide make disadvantageous decisions in other contexts, but nothing is known about the way they decide about the future. Can the willingness to postpone future gratification differentiate between individuals prone to serious, premeditated and less serious, unplanned suicidal acts?

Objectives-Lack of feeling connected and poor social problem solving has been described in suicide attempters. However, cognitive substrates of this apparent social impairment in suicide attempters remain unknown. One possible deficit, the inability to recognize others' complex emotional states has been observed not only in disorders characterized by prominent social deficits (autism-spectrum disorders and frontotemporal dementia) but also in depression and normal aging. This study assessed the relationship between social emotion recognition, problem solving, social functioning, and attempted suicide in late-life depression.Design, Participants, Measurements-There were 90 participants: 24 older depressed suicide attempters, 38 non-suicidal depressed elders, and 28 comparison subjects with no psychiatric history. We compared performance on the Reading the Mind in the Eyes test and measures of social networks, social support, social problem solving, and chronic interpersonal difficulties in these three groups.Results-Suicide attempters committed significantly more errors in social emotion recognition and showed poorer global cognitive performance than elders with no psychiatric history. Attempters had restricted social networks: they were less likely to talk to their children, had fewer close friends, and did not engage in volunteer activities, compared to non-suicidal depressed elders and those with no psychiatric history. They also reported a pattern of struggle against others and hostility in relationships, felt a lack of social support, perceived social problems as impossible to resolve, and displayed a careless/ impulsive approach to problems.Conclusions-Suicide attempts in depressed elders were associated with poor social problemsolving, constricted social networks, and disruptive interpersonal relationships. Impaired social NIH Public Access Author ManuscriptAm J Geriatr Psychiatry. Author manuscript; available in PMC 2012 March 1. NIH-PA Author ManuscriptNIH-PA Author Manuscript NIH-PA Author Manuscript emotion recognition in the suicide attempter group was related to global cognitive decline, thus it is possible that cognitive decline is one of the risk factors for suicide attempt in late-life, interacting with social deficits and psychosocial factors. ObjectivesSuicide rates are the highest in old age in almost every country in the world. Yet, it is difficult to identify those at risk, since known risk factors, such as depression, pain, disability, or financial problems have limited predictive power (1-3). The role of deficits in cognitive abilities is a poorly understood part of the suicidal diathesis (4,5), especially in older adults (6). The failure to deal with social stressors may play a particularly important role in suicidal behavior, and indeed suicide attempters report difficulties resolving social problems in questionnaire-based studies (7,8). However, cognitive substrates of this apparent social incompetence in suicide attempters remain unknown. It is conceivable that a misperception...