Delayed reward discounting and increased risk for suicide attempts among U.S. adults with probable PTSD

Associations among posttraumatic stress disorder symptoms, suicidal ideation, suicide attempts, and reward discounting

Posttraumatic stress disorder (PTSD) is associated with suicidal thoughts and behaviours. Decision-making processes and risk-taking are prominent for coping in both, but the implications for guaranteed and probabilistic reward discounting, important components in behavioural decision-making processes, are unclear. This study explored the relationships between PTSD and suicide risk with tendencies towards devaluing guaranteed rewards that are larger but delayed (i.e., delay discounting; DD) and devaluing larger but uncertain rewards (i.e., probability discounting; PD) for immediate but smaller rewards. The current study evaluated 498 participants (majority male [51.4%] and white [63.8%]; 33.3% screening positive for probable PTSD; 19.2% with lifetime suicide attempts; 30.8% with recent suicide ideation) on both delayed discounting and PD tasks. Provisional PTSD diagnosis, but not suicide attempts or ideation, was associated with increased PD (i.e., more devaluation of uncertain rewards). Conversely, PTSD interacted with both attempt history and ideation to predict increased delayed discounting (i.e., more devaluing of greater but delayed rewards). These results highlight how those with PTSD symptoms assign valuations to rewards, as well as how the addition of suicide risk interacts to impact these decision-making processes. While further research is needed, this suggests potential implications for treatment as they may benefit from structuring progress in smaller, more immediate goals.

Associations between PTSD and temporal discounting: The role of future thinking

BACKGROUND AND OBJECTIVES

Despite documented alterations in future thinking in posttraumatic stress disorder (PTSD), our understanding of how individuals with PTSD make future-oriented decisions is limited. We tested the hypothesis that increased discounting in association with PTSD reflects failure to spontaneously envision future rewarding situations.

METHODS

Thirty-seven trauma exposed war-zone veterans completed a standard temporal discounting task as well as a temporal discounting task accompanied by episodic future thinking cues.

RESULTS

Severity of PTSD symptoms was associated with preference for sooner, smaller rewards in the standard task. Consistent with our hypothesis, when participants engaged in future thinking, greater PTSD symptom severity was no longer associated with steeper discounting. Moreover, difficulty anticipating future events, as measured contemporaneously in a separate task (Verfaellie et al., 2024), mediated the relationship between PTSD symptom severity and degree of discounting in the standard task. Among PTSD symptom clusters, the severity of avoidance and negative alterations in cognition and mood was related to steeper discounting. Measures of depression and alcohol use were not associated with discounting.

LIMITATIONS

The sample included mostly male, predominantly White veterans who experienced primarily combat-related trauma.

CONCLUSIONS

PTSD-associated alterations in temporal discounting reflect failure to spontaneously imagine future positive events. Two common correlates of PTSD, depression and alcohol use, could not account for the observed associations between PTSD and future-oriented decisions.

Delay discounting is associated with addiction and mental health measures while controlling for health behaviors and health barriers in a large US sample

Background

Excessive discounting of future rewards [delay discounting (DD)] may be a transdiagnostic process and treatment target underlying behavioral health outcomes, including trauma, depression, anxiety, and problematic substance use. However, multiple health behaviors and barriers are also related to these outcomes, including social media usage, adverse childhood experiences (ACEs), sleep quality, healthcare access, housing status, and exercise. To extend research examining DD as transdiagnostic process, we recruited a large, heterogenous sample to examine the association between DD, problematic substance use, and mental health outcomes while controlling for certain health behaviors and health barriers.

Method

In a cross-sectional online survey of 3992 US residents, we administered validated measures of PTSD, depression, anxiety, and problematic alcohol, stimulant, and opioid use. Using linear or ordinal logistic models, scores for each outcome were regressed onto DD while controlling for demographics, health behaviors, and health barriers.

Results

Including only DD and demographics, DD was associated with each outcome at low effect sizes (ƒ2 = .013, OR range = 1.08-1.16). Except for opioid ASSIST scores, these relationships held when controlling for social media usage, sleep, housing status, healthcare access, ACEs, physical exercise, and demographic variables (ƒ2 = .002, OR range = 1.03-1.12), increasing confidence that DD concurrently and directly relates to four of these five clinical outcomes.

Discussion

These findings support the conceptualization of DD as a transdiagnostic process underlying certain psychopathologies and suggest targeting DD in co-occurring substance use disorder and/or mental health treatments may result in clinically significant outcomes.

Firearm ownership factors and cognitive functioning: A preliminary study

Recent studies have suggested that owning a firearm for the purpose of protection and intending to acquire a firearm within the next year are associated with disrupted cognitive-affective processes that may increase firearm suicide risk. Prior studies were limited by self-report measures and would benefit from the utilization of objective indicators of cognitive functioning to clarify associations between firearm ownership and cognitive-affective states. The present study examined objective cognitive performance in a sample of U.S. adults in relation to firearm ownership variables. Based on prior studies, we hypothesized that protective owners and individuals with the intention to acquire a firearm within the next year would demonstrate reduced performance on decision-making, mental flexibility, and emotional bias tasks. A total of 112 participants (61% female, 79% white) completed objective cognitive tasks following completion of a larger survey study through ResearchMatch. Results indicated that intention to purchase a firearm within the next year was not associated with cognitive functioning but was associated with an array of heightened psychiatric symptoms. Owning a firearm for the purpose of protection was associated with decreased mental flexibility relative to non-owners, but no differences were seen for decision-making or emotional bias. These findings represent the first attempt to examine underlying objective cognitive processes related to firearm ownership, and implications for future research are discussed.

Posttraumatic stress and delay discounting: a meta-analytic review

Delay discounting-the extent to which individuals show a preference for smaller immediate rewards over larger delayed rewards-has been proposed as a transdiagnostic neurocognitive process across mental health conditions, but its examination in relation to posttraumatic stress disorder (PTSD) is comparatively recent. To assess the aggregated evidence for elevated delay discounting in relation to posttraumatic stress, we conducted a meta-analysis on existing empirical literature. Bibliographic searches identified 209 candidate articles, of which 13 articles with 14 independent effect sizes were eligible for meta-analysis, reflecting a combined sample size of N = 6897. Individual study designs included case-control (e.g. examination of differences in delay discounting between individuals with and without PTSD) and continuous association studies (e.g. relationship between posttraumatic stress symptom severity and delay discounting). In a combined analysis of all studies, the overall relationship was a small but statistically significant positive association between posttraumatic stress and delay discounting (r = .135, p < .0001). The same relationship was statistically significant for continuous association studies (r = .092, p = .027) and case-control designs (r = .179, p < .001). Evidence of publication bias was minimal. The included studies were limited in that many did not concurrently incorporate other psychiatric conditions in the analyses, leaving the specificity of the relationship to posttraumatic stress less clear. Nonetheless, these findings are broadly consistent with previous meta-analyses of delayed reward discounting in relation to other mental health conditions and provide further evidence for the transdiagnostic utility of this construct.

Imagining emotional future events in PTSD: clinical and neurocognitive correlates

Emotional future thinking serves important functions related to goal pursuit and emotion regulation but has been scantly studied in posttraumatic stress disorder (PTSD). The current study sought to characterize emotional future thinking in PTSD and to identify clinical and neurocognitive profiles associated with potential alterations in the level of detail in narratives of imagined future events. Fifty-eight, trauma-exposed, war-zone veterans, who were classified into current PTSD, past PTSD, and no-PTSD groups, were asked to vividly imagine future events in response to positive and negative cue words occurring in the near and distant future. These narratives were scored for internal (i.e., pertaining to the main event) and external (i.e., tangential to the main event) details. Participants also performed neurocognitive tasks of generative ability, working memory, and relational verbal memory. Linear mixed modeling revealed that the current and past PTSD groups generated fewer internal details than the no-PTSD group across positive and negative cue words and across temporal proximity. Partial least squares analysis revealed that symptom severity for all PTSD clusters was inversely associated with production of internal details, albeit with the association relatively weaker for intrusion symptoms. Among the neurocognitive tasks, only relational verbal memory was associated with production of internal details. These findings suggest, as predicted, that functional avoidance may underlie reduced detail generation but also point to potential additional mechanisms to be further investigated. That future event simulation remains overgeneral even when PTSD symptoms abate highlights the importance of addressing alterations in future thinking in this population.

Toward objective characterizations of suicide risk: A narrative review of laboratory-based cognitive and behavioral tasks

Although suicide is a leading cause of preventable death worldwide, current prevention efforts have failed to substantively mitigate suicide risk. Suicide research has traditionally relied on subjective reports that may not accurately differentiate those at high versus minimal risk. This narrative review supports the inclusion of objective task-based measures in suicide research to complement existing subjective batteries. The article: 1) outlines risk factors proposed by contemporary theories of suicide and highlights recent empirical findings supporting these theories; 2) discusses ongoing challenges associated with current risk assessment tools and their ability to accurately evaluate risk factors; and 3) analyzes objective laboratory measures that can be implemented alongside traditional measures to enhance the precision of risk assessment. To illustrate the potential of these methods to improve our understanding of suicide risk, the article reviews how acute stress responses in a laboratory setting can be modeled, given that stress is a major precipitant for suicidal behavior. More precise risk assessment strategies can emerge if objective measures are implemented in conjunction with traditional subjective measures.

The relationship between disrupted anhedonia-related circuitry and suicidal ideation in major depressive disorder: A network-based analysis

BACKGROUND

Several epidemiological studies and psychological models have suggested that major depressive disorder (MDD) with anhedonia is associated with suicidal ideation (SI). However, little is known about whether the functional network pattern and intrinsic topologically disrupted in patients with anhedonia are related to SI.

METHODS

The resting-fMRI by applying network-based statistic (NBS) and graph-theory analyses was estimated in 273 patients with MDD (144 high anhedonia [HA], 129 low anhedonia [LA]) and 150 healthy controls. In addition, we quantified the SI scores of each patient. Finally, the mediation analysis assessed whether anhedonia symptoms could mediate the relationship between anhedonia-related network metrics and SI.

RESULT

The NBS analysis demonstrated that individuals with HA have a single abnormally increased functional connectivity component in a frontal-limbic circuit (termed the "anhedonia-related network", including the frontal cortex, striatum, anterior cingulate cortex and amygdala). The graph-theory analysis demonstrated that the anhedonia-related network showed a significantly disrupted topological organization (lower gamma and lambda), which the small-world property trend randomized. Furthermore, the anhedonia symptoms could mediate the relationship between the anhedonia-related network metrics (the mean functional connectivity values, the area under the curves values of gamma and nodal local efficiency in nucleus accumbens) and SI.

CONCLUSIONS

We found that disruption of the reward-related network in MDD leads to SI through anhedonia symptoms. These findings show the abnormal topological construction of functional brain network organization in anhedonia, shedding light on the neurological processes underlying SI in MDD patients with anhedonia symptoms.

Positive valence system function and anhedonia in middle-aged and older adults at high suicide risk

Positive valence systems are disrupted in late-life depression and in individuals at risk for suicide. The reward positivity (RewP) is an event-related potential measure of positive valence system function that relates to depression and anhedonia in children and young adults. However, it is unclear whether a reliable RewP signal can be elicited in middle-aged and older adults at high risk for suicide and, if so, whether this signal is similarly associated with clinical symptoms. In the current study, a RewP was elicited with a standard gambling task in middle-aged and older adults (N = 31) at discharge from a hospitalization for suicidal thought or behaviors. The resulting electrocortical response differed significantly for monetary wins compared to losses. Internal reliability of the RewP and the feedback negativity (FN) to monetary loss was good to excellent. Internal reliability of difference measures was lower but still largely acceptable, with residualized differences scores demonstrating stronger reliability than subtraction-based scores. A smaller residualized RewP, after accounting for the influence of the FN, was associated with greater severity of lassitude, an index of appetitive anhedonia. These findings set the groundwork for future studies of positive valence system function and depression in middle-aged and older adults at high risk for suicide.

The effect of social exclusion on intertemporal choice in suicide attempters: A preliminary experimental study

BACKGROUND

Suicide-related theories and a growing body of evidence suggest that suicidal patients may have a tendency toward "short-sightedness"-the preference for immediate gratification when making intertemporal choice-and that social exclusion may exacerbate this tendency in suicidal patients. The present study examined the intertemporal choice performance of suicide attempters under conditions of social exclusion in a sample of affective disorder patients.

METHODS

A total of 64 affective disorder patients (22 non-suicidal patients, 24 single-suicide attempters and 18 multiple-suicide attempters) completed an intertemporal choice task in an exclusion or a non-exclusion condition. Social exclusion was manipulated using the Cyberball paradigm.

RESULTS

Non-suicidal patients and single-suicide attempters both exhibited an exaggerated preference for immediate rewards in the exclusion condition compared with the non-exclusion condition; in contrast, the multiple-suicide attempters appeared relatively indifferent to the social exclusion, exhibiting virtually identical preferences for immediate rewards in both the exclusion and non-exclusion conditions. In addition, the multiple-suicide attempters exhibited an exaggerated preference for immediate rewards compared with non-suicidal patients and single-suicide attempters in the non-exclusion condition, while the three groups did not differ in the exclusion condition.

CONCLUSIONS

Affective disorder patients with a single or no suicide attempts are more short-sighted after being excluded, while those with multiple suicide attempts appeared consistent short-sightedness in both exclusion and non-exclusion conditions. The study provides preliminary evidence of the role of disadvantageous intertemporal choice in the suicidal process. Future research replicate and extend these findings could have implications for suicide prevention and intervention.

Self-injurious thoughts and behaviors and alterations in positive valence systems: A systematic review of the literature

Self-injurious thoughts and behaviors (SITBs), which include suicidal ideation (SI), suicide attempts (SA), and nonsuicidal self-injury (NSSI), are prevalent and associated with impairments in functioning and elevated risk of suicide deaths. Preventing suicide is a complex problem, with numerous systems likely contributing to the onset and maintenance of SITBs, and there is a critical need to identify more precise predictors of risk. Positive valence systems (PVS) are an understudied domain with promise for improving understanding of risk processes underlying SITBs. In this systematic review, we evaluate the evidence for the potential role of altered PVS function in SI, SA, and/or NSSI, including alterations in reward responsiveness, learning, and valuation assessed through behavioral, physiological and circuit measures. Results provide preliminary support for associations between distinct aspects of PVS function and alterations in SITBs. Specifically, SI appears to be characterized by low reward responsiveness, whereas little research has examined reward responsiveness in SA, and NSSI has been characterized by hyper-responsiveness to rewards. Alterations in reward learning and valuation are commonly examined in SA, with some evidence that they may be more strongly associated with attempts than SI or NSSI. At the same time, the literature is limited in that some constructs are commonly examined in one form of SITBs but not others. Further, research is predominantly cross-sectional and focused on adults, raising questions about the role of PVS function in developmental pathways to SITBs. We conclude by integrating the research to date and highlighting promising directions for future research.

Anhedonia and Suicide

Suicide is a leading cause of death, and presently, there is no definitive clinical indicator of future suicide behaviors. Anhedonia, a transdiagnostic symptom reflecting diminished ability to experience pleasure, has recently emerged as a risk factor for suicidal thoughts and behaviors (STBs). This overview, therefore, has the following aims. First, prior research relating anhedonia to STBs will be reviewed, with a particular focus on clarifying whether anhedonia is more closely associated with suicidal thoughts versus behaviors. Second, the National Institute of Mental Health's Research Domain Criteria Positive Valence Systems provide a useful heuristic to probe anhedonia across different units of analysis, including clinical symptoms, behaviors, neural mechanisms, and molecular targets. Accordingly, anhedonia-related constructs linked to STBs will be detailed as well as promising next steps for future research. Third, although anhedonia is not directly addressed in leading suicide theories, this review will provide potential inroads to explore anhedonia within diathesis-stress and interpersonal suicide frameworks. Last, novel approaches to treat anhedonia as a means of reducing STBs will be examined.

Does positive feeling lead to more impulsiveness? - Implication of previous rewarded experience on location-dependent motoric impulsivity

Positive feeling or rewarding experience is crucial for individuals to operative their cognitive activities via an outcome evaluation of incentive reinforcement. For a long time, rewarding process or outcome evaluation is assumed greatly influenced by neuronal construct that holds individuals' impulsiveness, a capacity to inhibit unwanted behaviors provoked in a given situation. In the present study, we proposed that the outcome evaluation or rewarding experience can influence the occurrence of impulsiveness too. We hypothesized that animals would be more likely to deliver impulsive action in the place where it was previously associated with reinforcing process, in which central dopamine may play an important role. By employing five-choice serial reaction time task (5-CSRTT), we examined whether one of the five holes where rats made a correct response to get the reward would gain a higher probability to deliver premature or perseverative activities than other holes in the next trial of 5-CSRTT under baseline or longer waiting period condition. The effects of D1 receptor antagonist SCH23390 were also evaluated in the above paradigm. We demonstrated that (i) the influence on motoric impulsive response from previous rewarded experience can be described in a behavioral paradigm such as the 5-CSRTT, (ii) both prematures and perseverations at the hole associated with previous rewarding were about one-fifth of probability, however were statistically not correlated unless the interventions of inter-trial interval = 7 plus SCH23390, and (iii) the hole associated with the positive reinforcement of the 5-CSRTT appears more likely for rats to carry out an intuitive impetus under SCH23390 in a longer waiting condition. Our results may shed some insight toward the role of rewarding process in impulsive behavior.