Frontal Motor Cortex Activity During Reactive Control Is Associated With Past Suicidal Behavior in Recent-Onset Schizophrenia

Suicidal thoughts and behaviours among military veterans: protocol for a prospective, observational, neuroimaging study

INTRODUCTION

This study's overarching goal is to examine the relationship between brain circuits and suicidal thoughts and behaviours (STBs) in a transdiagnostic sample of US military veterans. Because STBs have been linked with maladaptive decision-making and disorders linked to impulsivity, this investigation focuses on valence and inhibitory control circuits.

METHODS AND ANALYSIS

In this prospective, observational study, we will collect functional MRI (fMRI), cognitive and clinical data from 136 veterans (target sample size) recruited from the Providence VA Health System (PVAHS): 68 with STBs and 68 matched controls. Behavioural data will be collected using standardised measures of STBs, psychiatric symptoms, cognition, functioning and medical history. Neuroimaging data will include structural, task and resting fMRI. We will conduct follow-up interviews and assessments at 6, 12 and 24 months post-enrolment. Primary analyses will compare data from veterans with and without STBs and will also evaluate whether activation and connectivity within circuits of valence and inhibition covary with historical and prospective patterns of suicidal ideation and behaviour.

ETHICS AND DISSEMINATION

The PVAHS Institutional Review Board approved this study (2018-051). Written informed consent will be obtained from all participants. Findings from this study will be published in peer-reviewed journals and presented at local, regional, national and international conferences.Nauder Namaky, Ph.D.* nauder_namaky@brown.edu.

History of suicide attempts associated with the thinning right superior temporal gyrus among individuals with schizophrenia

Individuals with schizophrenia have higher rates of suicide attempts than the general population. Specific cortical abnormalities (e.g., the cortical surface area and thickness) may be associated with a history of suicide attempts. We recruited 74 individuals with schizophrenia (37 suicide attempters were individually matched with 37 non-attempters on age, sex, phase of illness, and study center) and 37 healthy volunteers. The cortical surface area and thickness data were extracted from structural MRI and compared between the groups. Suicide attempters showed significantly smaller surface areas in the whole brain (p = .028, Cohen's d = -0.54) than non-attempters. No association was found between the cortical surface area of individual brain regions and a history of suicide attempts. The mean cortical thickness did not differ significantly between the groups; however, suicide attempters demonstrated a thinner cortex in the right superior temporal gyrus (p < .001, q = 0.037, Cohen's d = -0.88). These findings indicate that a history of suicide attempts among individuals with schizophrenia is associated with a reduction in the global cortical surface area and specific cortical thinning of the right superior temporal gyrus. The morphometric alteration of the right superior temporal gyrus may represent a biomarker of suicidal behavior in individuals with schizophrenia.

Aberrant frontolimbic circuit in female depressed adolescents with and without suicidal attempts: A resting-state functional magnetic resonance imaging study

BACKGROUND

The neurobiological basis of suicidal behaviors among female adolescents with major depressive disorder (MDD) remains largely unclear.

MATERIALS AND METHODS

Fifty-eight drug-naïve, first-episode female adolescent MDD [including 31 patients with suicidal attempt (SA group) and 27 patients without SA (non-SA group)], and 36 matched healthy controls (HCs) participated in the present study. Resting-state functional magnetic resonance imaging (MRI) was performed on each subject. The metrics of the amplitude of low-frequency fluctuation (ALFF), fractional ALFF (fALFF), and regional homogeneity (ReHo) were compared among the three groups. Then seed-based functional connectivity (FC) was conducted based on the ALFF/fALFF and ReHo results, which were then correlated to clinical variables.

RESULTS

Compared with the non-SA group, the SA group exhibited increased fALFF in the bilateral insula and right precentral gyrus, and enhanced ReHo in the left superior temporal gyrus, left middle cingulate cortex, right insula, and right precentral gyrus. Relative to the HCs, the SA group demonstrated additionally reduced fALFF and ReHo in the left middle frontal gyrus. Moreover, the SA group showed increased FC between the right precentral gyrus and the left middle frontal gyrus and left insula, and between the right insula and anterior/middle cingulate cortex compared to the non-SA and HC groups. In addition, the fALFF in the left middle frontal gyrus was positively correlated with the 17-item Hamilton Depression Rating Scale scores, and the values in the fALFF/ReHo in the right insula were positively correlated with the duration of MDD within the patient group.

CONCLUSION

These findings highlight the multiple abnormalities of the frontolimbic circuit, which may enhance our understanding of the neurobiological basis underlying female MDD with SA during adolescence.

An exploratory magnetic resonance imaging study of suicidal ideation in individuals at clinical high-risk for psychosis

Suicide is a major cause of death in psychosis and associated with significant morbidity. Suicidal ideation (SI) is very common in those at clinical high-risk for psychosis (CHR) and predicts later suicide. Despite substantial work on the pathobiology of suicide in schizophrenia, little is known of its neurobiological underpinnings in the CHR or putatively prodromal state. Therefore, in this pilot study, we examined the neurobiology of SI in CHR individuals using structural MRI. Subjects were aged 14-30 and met criteria for the Attenuated Positive Symptom Psychosis-Risk Syndrome (APSS) delineated in the Structured Interview for Psychosis-Risk Syndromes (SIPS). Suicidality was assessed using the Columbia Suicide Severity Rating Scale (C-SSRS). Volumetric MRI scans were obtained on a 3T Phillips scanner. MRI data were available for 69 individuals (19 CHR without SI, 31 CHR with SI and 19 healthy control subjects). CHR individuals with SI had thicker middle temporal and right insular cortices than CHR individuals without SI and healthy control subjects. The location of these findings is consistent with neurobiological findings regarding suicide in syndromal psychosis. These findings underscore the potential for the use of brain imaging biomarkers of suicide risk in CHR individuals.

The processing of angry faces in schizophrenia patients with a history of suicide: An fMRI study examining brain activity and connectivity

BACKGROUND

The high rate of suicidal behaviours (SBs) in psychiatric populations remain an important preoccupation to address. The literature reveals emotional instability as an important risk factor for SBs. However, the neural mechanisms underpinning this risk factor have never been investigated in schizophrenia patients with SBs. The following study implemented a task-based emotional processing functional magnetic resonance imaging (fMRI) paradigm to evaluate the activation and connectivity differences exhibited by schizophrenia patients with a history of suicide attempt (SA).

METHOD

A sample of 62 schizophrenia patients with and without SA and 22 controls completed an fMRI emotional processing task, which included the visualization of dynamic angry facial expressions. Task-based connectivity was assessed using generalized psychophysical interaction analyses.

RESULTS

During the processing of angry faces, suicidal schizophrenia patients displayed increased activation of the left median cingulate gyrus, left middle frontal gyrus, and left precuneus when compared to nonsuicidal schizophrenia patients and healthy controls. Whole-brain connectivity analyses yielded an increased coupling of the right amygdala and right superior frontal gyrus, as well as between the left precuneus and median cingulate gyrus, in suicidal schizophrenia patients. Schizophrenia patients' hostility scores on the Positive and Negative Symptom Scale (PANSS) were significantly and positively correlated with the activity of the left median cingulate gyrus.

CONCLUSION

When exposed to angry faces, suicidal schizophrenia patients demonstrate elevated activation of brain regions associated to executive functioning and self-processing, as well as aberrant fronto-limbic connectivity involved in emotion regulation. Our results highlight the neglected role of anger when investigating the neural alterations underpinning SBs in schizophrenia.

The Association Between Insular Subdivisions Functional Connectivity and Suicide Attempt in Adolescents and Young Adults with Major Depressive Disorder

Previous studies demonstrated the possible involvement of insula in suicide owing to depression. However, the function of insula in young depressed patients with suicide attempt (SA) remains to be revealed. This study aimed to explore the association between resting-state functional connectivity (FC) of insula and SA in young depressed patients. Fifty-eight adolescents and young adults with major depressive disorder, including 22 with a history of at least one SA (SA group) and 36 without a history of SA (NSA group) were scanned with a 3.0T functional magnetic resonance imaging system, and the resting-state functional magnetic resonance imaging data was extracted. Whole brain resting-state FC of insular subdivisions were compared between the two groups. Significantly increased FC of the left posterior insula with the orbital part of left inferior frontal gyrus, the right supplementary motor area and the bilateral paracentral lobule extending to the bilateral middle cingulate cortex was observed in the SA group compared with the NSA group. In addition, the orbital part of left superior frontal gyrus in the SA group exhibited significantly increased FC with the right posterior insula compared with the NSA group. However, no significant correlation was found between the insular subdivisions FC and different clinical variables in two groups. The present study highlighted the disruptions of the resting-state FC of the posterior insula with the orbitofrontal cortex and a series of motor cortices, and added incremental value to the knowledge of the neural mechanism underlying SA in young depressed patients.

Brain grey matter abnormalities in first episode non-affective psychosis patients with suicidal behaviours: The role of neurocognitive functioning

BACKGROUND

Suicide is one of the leading causes of premature death in first-episode psychosis (FEP) patients. The understanding of suicidal behaviour (SB) is limited, and new and integrative approaches focusing on the likely relationship of the biological and cognitive features of SB in the early phases of psychosis are warranted. We aimed to study the relationship of brain grey matter anomalies and cognitive functioning with SB or suicidal risk in a large sample of non-affective FEP patients.

METHODS

We used a voxel-based morphometry analysis in 145 FEP patients to investigate the pattern of structural brain abnormalities related to SB. In addition, bivariate and multivariate analyses were performed to explore the relationship between cognitive functioning and SB.

RESULTS

A reduction in grey matter volume in the frontal area, temporal gyrus, precuneus, uncus, amygdala, left cuneus and subcallosal gyrus as well as a marked regional volume reduction in the right hemisphere was linked with the presence of SB. Additionally, worse global cognitive functioning and living in urban areas were identified as suicide risk factors.

CONCLUSIONS

This study provides some insights about the brain abnormalities associated with SB in FEP patients. Specifically, the areas reported are involved in important functions related to SB, such as impulsivity, problem solving or responses to pain. Thus, the results confirm the relevant role of cognitive functioning on SB.

The neurobiology of suicide in psychosis: A systematic review

The lifetime risk of dying by suicide in schizophrenia and related psychoses has been estimated to be approximately between 5% and 7%, though some have estimated that the number is closer to 10%. The highest risk for suicide occurs within the first year after presentation, when patients have a 12 times greater risk of dying by suicide than the general population, or a 60% higher risk compared with patients in other phases of psychosis, although the risk continues for many years. Some 31% of all deaths in first and early episode samples are due to suicide. Studies in individuals at clinical high-risk for psychosis (CHR) or with attenuated positive symptoms also demonstrate that suicidality is common and problematic in these individuals. Therefore, suicide in psychosis is a particularly severe problem. In order to develop interventions aimed at reducing the risk of suicide in psychotic individuals, it will be critical to understand the neurobiology of suicide in psychosis. In this paper, I report on the results of a systematic review of the work done to date on the neurobiology of suicide in psychosis and on suicidality in the CHR period. I will also identify gaps in knowledge and discuss future strategies for studying the neurobiology of suicidality in psychosis that may help to disentangle the links between suicide and psychosis and, by doing so, allow us to gain a greater understanding of the relationship between suicide and psychosis, which is critical for developing interventions aimed at reducing the risk of suicide in psychotic individuals.

Imaging suicidal thoughts and behaviors: a comprehensive review of 2 decades of neuroimaging studies

Identifying brain alterations that contribute to suicidal thoughts and behaviors (STBs) are important to develop more targeted and effective strategies to prevent suicide. In the last decade, and especially in the last 5 years, there has been exponential growth in the number of neuroimaging studies reporting structural and functional brain circuitry correlates of STBs. Within this narrative review, we conducted a comprehensive review of neuroimaging studies of STBs published to date and summarize the progress achieved on elucidating neurobiological substrates of STBs, with a focus on converging findings across studies. We review neuroimaging evidence across differing mental disorders for structural, functional, and molecular alterations in association with STBs, which converges particularly in regions of brain systems that subserve emotion and impulse regulation including the ventral prefrontal cortex (VPFC) and dorsal PFC (DPFC), insula and their mesial temporal, striatal and posterior connection sites, as well as in the connections between these brain areas. The reviewed literature suggests that impairments in medial and lateral VPFC regions and their connections may be important in the excessive negative and blunted positive internal states that can stimulate suicidal ideation, and that impairments in a DPFC and inferior frontal gyrus (IFG) system may be important in suicide attempt behaviors. A combination of VPFC and DPFC system disturbances may lead to very high risk circumstances in which suicidal ideation is converted to lethal actions via decreased top-down inhibition of behavior and/or maladaptive, inflexible decision-making and planning. The dorsal anterior cingulate cortex and insula may play important roles in switching between these VPFC and DPFC systems, which may contribute to the transition from suicide thoughts to behaviors. Future neuroimaging research of larger sample sizes, including global efforts, longitudinal designs, and careful consideration of developmental stages, and sex and gender, will facilitate more effectively targeted preventions and interventions to reduce loss of life to suicide.

A qualitative systematic review of suicide behavior using the cognitive systems domain of the research domain criteria (RDoC) framework

Neurocognitive deficits are associated with both suicide behavior (SB) and psychiatric disorders. Application of a transdiagnostic framework to identify neurocognitive commonalities of SB may clarify important risk factors of SB across psychiatric disorders. The aim of this study was to conduct a qualitative systematic literature review of SB using the Research Domain Criteria (RDoC) Cognitive Systems framework to determine if cognitive deficits exist independently of psychiatric disorders in SB. The following six constructs that encompass the Cognitive Systems domain were assessed: 1) Attention, 2) Cognitive Control, 3) Declarative Memory, 4) Language, 5) Perception, and 6) Working Memory. A total of 1386 abstracts were identified and 74 studies met the inclusion criteria for this review. The majority of studies reviewed (65%) had significant differences in cognition between individuals with and without SB. Seventy-nine percent of studies with a patient control group showed significant cognitive deficits in SB groups. Deficits in cognitive control were associated with SB and had the greatest percentage of studies with significant main findings. Use of the RDoC cognitive systems framework to evaluate SB revealed that cognitive deficits may be a transdiagnostic risk factor for SB, especially alterations in cognitive control.

Cortical biometals: Changed levels in suicide and with mood disorders

BACKGROUND

Changes in levels of metals have been suggested to contribute to the pathophysiologies of several neurodegenerative disorders but to our knowledge this is the first metallomic study in CNS from patients with mood disorders. The focus of this study was on cortical regions affected by the pathophysiologies of bipolar disorders and major depressive disorders.

METHODS

Levels of metals were measured using inductively coupled plasma mass spectrometry in Brodmann's areas (BA) 6, 10 and 17 from patients with major depressive disorders (n = 13), bipolar disorders (n = 12) and age / sex matched controls (n = 13).

RESULTS

There were lower levels of cortical strontium (BA 6 & 10), ruthenium (BA 6 & 17) and cadmium (BA 10) from patients with major depressive disorder as well as lower levels of strontium in BA 10 from patients with bipolar disorders. Unexpectedly, there were changes in levels of 16 metals in the cortex, mainly BA 6, from suicide completers compared to those who died of other causes.

LIMITATIONS

Cohort sizes were relatively small but comparable with many studies using human postmortem CNS. Like all studies on non-treatment naïve patients, drug treatment was a potential confound in our experiments.

CONCLUSIONS

Our exploratory study suggests changes in levels of metals in bipolar disorders and major depressive disorders could be affecting cortical oxidative balance in patients with mood disorders. Our data raises the possibility that measuring levels of specific biometals in the blood could be used as a biomarker for increased risk of suicide.

Structural and functional alterations of the suicidal brain: An updated review of neuroimaging studies

Brain imaging is a non-invasive and in vivo direct estimation of detailed brain structure, regional brain functioning and estimation of molecular processes in the brain. The main objective of this review was to analyze functional and structural neuroimaging studies of individuals at risk for suicide. We reviewed articles published between 2005 and 2018, indexed in PubMed and Medline, assessing structural and functional alterations of the brain of individuals at high risk for suicide and at low risk for suicide. We reviewed functional and structural neuroimaging studies which included individuals with a history of suicidal ideation or attempt in major depressive disorder (MDD), bipolar disorder (BD), psychosis, and borderline personality disorder (BPD). We selected 45 papers that focused on suicidality in MDD, 17 papers on BD, 11 papers on psychosis, and 5 papers on BPD. The suicidal brain across psychiatric diagnoses seems to heavily involve dysfunction of the fronto-temporal network, primarily involving reductions of gray and white matter volumes in the pre-frontal cortex (PFC), anterior cingulate, and superior temporal gyrus. Nonetheless, there are several ways to define suicidal behaviour and ideation. Therefore, it still remains difficult to combine the evidence from imaging studies that used different definitions of suicidality.

Neural Correlates of Emotion Regulation and Adolescent Suicidal Ideation

BACKGROUND

Research on the neural correlates associated with risk for suicidal ideation (SI) has been limited, particularly in one increasingly at-risk group-adolescents. Previous research with adolescents indicates that poor emotion regulation skills are linked with SI, but these studies have not previously examined neural activation in service of emotion regulation between those with and without SI histories.

METHODS

Here we examine whether SI is associated with neural responses during an emotion regulation functional magnetic resonance imaging task in a group of adolescents (N = 49) 13 to 20 years of age (mean = 16.95).

RESULTS

While there were no differences between youths with and without SI in self-reported emotional responses to negative pictures, youths with SI activated the dorsolateral prefrontal cortex more than youths without SI on trials in which they attempted to regulate their emotional responses compared with trials in which they passively viewed negative pictures. In contrast, during passive viewing of negative stimuli, youths with SI activated the dorsolateral prefrontal cortex, temporoparietal junction, and cerebellum less than same-age control subjects.

CONCLUSIONS

These findings were robust to control subjects for depression and adversity exposure and are consistent with the idea that youths with SI have disrupted emotion regulation, potentially related to differences in recruitment of top-down control regions. In contrast, youths without SI activated regions implicated in emotion regulation even when not directed to effortfully control their emotional response. This is the first study to examine neural function during emotion regulation as a potential neural correlate of risk for SI in adolescents.

Recent advances in differentiating suicide attempters from suicide ideators

PURPOSE OF REVIEW

This article summarizes findings from recent studies (published since 2015) examining differences between suicide attempters and suicide ideators.

RECENT FINDINGS

Converging evidence suggests that the capability to attempt suicide (e.g., acquired capability, painful and provocative experiences, high tolerance for pain and distress) is higher in suicide attempters than suicide ideators. Other psychosocial and biological differences have also been identified but require replication.

SUMMARY

Recent literature reviews find that traditional risk factors for suicide - such as depression, hopelessness, most psychiatric disorders, and even impulsivity - robustly predict suicide ideation but poorly predict suicide attempts among ideators. To address this knowledge gap, studies are increasingly employing an ideation-to-action framework. This framework views the development of suicide ideation and the progression from ideation to potentially lethal attempts as distinct processes with distinct explanations and predictors. Converging evidence suggests that factors associated with diminished fear of pain, injury, and death can increase one's capability to attempt suicide and facilitate the progression from suicidal thoughts to suicidal acts. Recent studies have also identified other variables that may differentiate attempters from ideators, but these require replication. Theories of suicide positioned within the ideation-to-action framework provide testable and promising hypotheses about the progression from ideation to attempts. These include the Interpersonal Theory, Integrated Motivational-Volitional Model, and Three-Step Theory.