Examining multiple features of episodic future thinking and episodic memory among suicidal adults

Ventromedial prefrontal cortex activation and neurofeedback modulation during episodic future thinking for individuals with suicidal thoughts and behaviors

Individuals experiencing suicidal thoughts and behaviors (STBs) show less specificity and positivity during episodic future thinking (EFT). Here, we present findings from two studies aiming to (1) further our understanding of how STBs may relate to neural responsivity during EFT and (2) examine the feasibility of modulating EFT-related activation using real-time fMRI neurofeedback (rtfMRI-nf). Study 1 involved 30 individuals with major depressive disorder (MDD; half with STBs) who performed an EFT task during fMRI, for which they imagined personally-relevant future positive, negative, or neutral events. Positive EFT elicited greater ventromedial prefrontal cortex (vmPFC) activation compared to negative EFT. Importantly, the MDD + STB group exhibited reduced vmPFC activation across all EFT conditions compared to MDD-STB; although EFT fluency and subjective experience remained consistent across groups. Study 2 included rtfMRI-nf focused on vmPFC modulation during positive EFT for six participants with MDD + STBs. Results support the feasibility and acceptability of the rtfMRI-nf protocol and quantitative and qualitative observations are provided to help inform future, larger studies aiming to examine similar neurofeedback protocols. Results implicate vmPFC blunting as a promising treatment target for MDD + STBs and suggest rtfMRI-nf as one potential technique to explore for enhancing vmPFC engagement.

Clinical and electrophysiological correlates of hopelessness in the context of suicide risk✰

Hopelessness is a key risk factor for suicide. This analysis explored whether hopelessness indicates a recent suicide crisis state and is linked with magnetoencephalography (MEG) oscillatory power and effective connectivity differences. Change in hopelessness ratings and effective connectivity post-ketamine were also evaluated in a subsample of high-risk individuals to evaluate correlates of dynamic changes over time. Participants (66F;44 M;1 transgender) included individuals with suicide crisis in the last two weeks (High Risk (HR), n = 14), those with past suicide attempt but no recent suicide ideation (SI) (Low Risk (LR), n = 37), clinical controls (CC, n = 33), and healthy volunteers at minimal risk (MinR, n = 27). MEG oscillatory power and clinical hopelessness ratings (via the Beck Hopelessness Scale (BHS)) were evaluated across groups. Dynamic casual modeling (DCM) evaluated connectivity within and between the anterior insula (AI) and anterior cingulate cortex (ACC). A subsample of HR individuals who received ketamine (n = 10) were evaluated at Day 1 post-infusion. The HR group reported the highest levels of hopelessness, even when adjusting for SI. MEG results linked hopelessness with reduced activity across frequency bands in salience network regions, with no group or group-by-interaction effects. Using DCM, the HR group had reduced intrinsic drive from granular Layer IV stellate cells to superficial pyramidal cells in the ACC and AI. In the pilot HR study, reduced hopelessness was linked with increased drive for this same connection post-ketamine. Hopelessness is a possible proxy for suicide risk. Electrophysiological targets for hopelessness include widespread reductions in salience network activity, particularly in the ACC and AI.

An examination of episodic future thinking in the emergency department among youth experiencing suicidal thoughts and behaviors

Youth experiencing suicidal thoughts and/or behaviors (STBs) frequently present to emergency departments for acute psychiatric care. These settings offer a transitory yet pivotal opportunity to assess, intervene on, and plan continued care for STBs. This study examined a clinically relevant, understudied aspect of psychological functioning among youth experiencing STBs in the emergency department: episodic future thinking, or the ability to imagine discrete autobiographical future events. A sample of 167 youths (10-17 years) presenting to a pediatric psychiatric emergency department for STBs completed a performance-based measure of episodic future thinking assessing richness in detail and subjective characteristics of imagined future events. STB recurrence was assessed 6 months later. Immediately following a suicide-related crisis, youth demonstrated mixed abilities to imagine their future: they generated some concrete future event details but did not subjectively perceive these events as being very detailed or likely to occur. Older adolescents (i.e., 15-17) generated more episodic details than pre-/younger adolescents (i.e., 10-14), particularly those pertaining to actions or sensory perceptions. There was no evidence linking less detailed episodic future thinking and greater likelihood of STBs following the emergency department visit; instead, hopelessness was a more robust risk factor. Findings underscore the importance and clinical utility of better understanding the psychological state of youth during or immediately following a suicide-related crisis. In particular, assessing youths' future thinking abilities in the emergency department may directly inform approaches to acute care delivery.

Induced optimism to lessen hopelessness-related cognitions among young adults at risk for suicidal thoughts and behavior

Background

Hopelessness is one of the best-studied cognitive predictors of depression and suicide. Previous research suggests that hopelessness may develop through repetitive thinking about the occurrence of positive and negative future outcomes. The present study sought to investigate whether mental rehearsal in making optimistic future-event predictions, or induced optimism, would lead to reductions in hopelessness, particularly among individuals with a history of suicide ideation or suicide attempts.

Methods

Participants with (n = 58) and without (n = 76) a history of suicide ideation or attempts were randomly assigned to either practice making optimistic future-event predictions or to a control condition in which they practiced making a lexical decision (using the same stimuli) over three study sessions, each separated by one week.

Results

Findings offered modest support for the hypothesis that induced optimism would decrease hopelessness but not improve mood; this was regardless of history of suicide ideation or attempts.

Limitations

The sample was predominantly female, and assessment of suicide ideation and attempt history was not confirmed by clinical interview, which may limit generalizability.

Conclusion

Practice in making optimistic future-event predictions over time may be one way to reduce the hopelessness-related cognitions that confer vulnerability to suicide ideation and behavior.