Suicide is a global public health issue, claiming over 700,000 lives annually worldwide. Opportunities for intervention are ample, as half of suicide decedents contacted a health care provider within a month of their deaths. In these encounters, suicide risk assessments are based on patients' self-report of suicidal intent and chronic risk factors, such as past attempts and prior psychiatric diagnoses. Yet, up to 75% of those dying by suicide explicitly denied suicidal intent at their last meeting with a health professional¹, and almost 20% of suicide attempters do not have a diagnosable mental disorder². Moreover, traditional risk factors, such as previous suicide attempts and history of mental illness, do not reliably predict short-term suicide risk³.

Over the last decade, several independent research teams have documented the existence of specific acute mental states associated with emergence of suicidal behavior. However, neither the DSM nor the ICD ever carried a diagnosis referring to these states. The suicide crisis syndrome (SCS) aims to fill this gap in psychiatric nosology and is under review for inclusion in the DSM. This diagnosis provides a systematic tool for recognizing and treating a mental disorder presenting imminent suicide risk without relying on self-reported suicidal intent⁴.

SCS is the last and most acute stage of the Narrative Crisis Model of suicide (NCM), which reflects the progression of suicidal risk from chronic risk factors to imminent suicidal risk, and provides a comprehensive framework for the design and implementation of treatments that specifically target each of the four stages in the suicidal process⁵.

The empirically-driven SCS criteria have evolved iteratively over a period of 15 years. They incorporate five empirically validated domains, which together constitute a unidimensional syndrome. Suicidal ideation is not included, due to its demonstrated unreliability as an indicator of imminent suicidal behavior. The first SCS domain, criterion A, features a persistent and intense feeling of frantic hopelessness, in which the individual feels trapped in a situation experienced both as intolerable and inescapable. Criterion B includes four distinct symptom dimensions: B1 Affective disturbance, B2 Loss of cognitive control, B3 Hyperarousal, and B4 Social withdrawal.

B1 Affective disturbance may manifest itself through: 1) emotional pain, 2) depressive turmoil; 3) extreme anxiety with unusual physical sensations; and 4) acute anhedonia. B2 Loss of cognitive control involves: 1) ruminations; 2) cognitive rigidity; 3) failed thought suppression; and 4) ruminative flooding – loss of control over thoughts accompanied by headaches or head pressure. B3 Hyperarousal involves: 1) agitation/restlessness; 2) hypervigilance, i.e. an intense and exaggerated responsiveness to sensory inputs; 3) irritability; and 4) insomnia. Finally, B4 Social withdrawal involves avoidance of social engagements and evasive communication with others.

To be diagnosed with SCS, patients must meet criterion A and have at least one symptom from each of criteria B1-B4.

Several SCS assessment instruments have been developed for use among diverse populations. The latest validated self-report measures are the Revised Suicide Crisis Inventory (SCI-2) and the Suicide Crisis Inventory - Short Form (SCI-SF). The full 61-item SCI-2 reflects the five dimensions of SCS, with items rated on a 5-point Likert scale. Clinician-rated measures include the proxy-validated 14-item SCS Checklist (SCS-C)⁶, and the clinically implemented Abbreviated SCS Checklist (A-SCS-C), a 5-item checklist reflecting the five symptom domains⁷. Both checklists give a dichotomous present or absent SCS diagnosis.

SCS demonstrated excellent internal consistency within and across the five symptom dimensions in US and international samples. Several US studies – as well as those conducted in India, Korea, Taiwan, Russia and Brazil – further supported the unidimensionality and 5-factor structure of SCS. Both SCI and SCI-2 scores were associated with concurrent (past month) and lifetime suicidal ideation and behaviors, and showed discriminant validity for symptoms of depression, anxiety and psychosis⁸.

To date, over fifteen studies have demonstrated the predictive validity of SCS for imminent suicidal ideation, preparatory actions and suicidal attempts. Furthermore, when compared to concurrent and past suicidal ideation or attempts, SCS – as measured by the SCI and SCI-2 – was either the only significant predictor of suicide attempt, or showed incremental predictive validity for suicidal thoughts and behaviors at one-month follow-up⁹. The best prediction of suicidal behaviors was achieved when all five components of SCS were considered.

As a categorical objective diagnosis, SCS provides actionable information for front-line clinicians, potentially simplifying clinical decision-making when working with high-risk patients in emergency rooms, inpatient units, and outpatient offices. Most importantly, clinical use of SCS has resulted in high perceived clinical utility by clinicians as well as actual clinical utility in admit/discharge clinical decisions (91% concordance with SCS present/absent diagnosis). Moreover, patients with SCS had a 75% lower post-discharge general and suicide-specific emergency room readmission rate vs. those without this diagnosis.

In light of the psychometric strength and clinical utility of SCS, an increasing number of clinical settings around the world are integrating SCS diagnostic tools into their routine workflow (specifically, in Israel, Hungary, Norway, Taiwan, Chile, Turkey and Spain). To that end, the SCI-2 and SCS-C have been translated into 14 different languages across 16 countries and four continents. An ongoing study using the data from the International Suicide Prevention Assessment Research Collaboration suggests that SCS is an excellent cross-cultural predictor of concurrent suicidal behaviors, with an area under the curve ranging from 0.83 to 0.95.

The rapid dissemination of SCS assessment as a clinical tool, and its proposal for inclusion in the DSM as a suicide-specific diagnosis, have opened the door to important research questions. First, the evidence about the discriminative validity of SCS vs. other DSM conditions needs to be enhanced. While SCS has divergent validity with regard to dimensional measures of depression, hostility, phobic anxiety and interpersonal problems, discriminant validity with several diagnoses – such as major depression, panic disorder and post-traumatic stress disorder – is under investigation. Second, the duration of SCS requires clarification, as well as the relationship between repeated SCS episodes and risk for suicidal behaviors. Third, further validation is needed of the clinical utility of SCS assessment as a clinical decision tool across diverse outpatient, inpatient and emergency settings globally. Lastly, clinical trials are needed to assess the effectiveness of pharmacological and psychotherapy treatments for SCS. All of these questions are currently being investigated by our group and dozens of other researchers around the world.

A DSM (and possibly ICD) diagnosis of SCS with an assigned diagnostic code would provide clinicians with a systematic means for assessing and reducing imminent suicide risk, even in high-risk individuals denying suicidal ideation and intent, while distinguishing patients with self-reported suicidal ideation at little risk of suicidal behavior. Furthermore, the conceptual and operational clarity of SCS would likely decrease clinicians’ anxiety about working with suicidal patients, in turn promoting the development of an effective therapeutic alliance. Lastly, we believe that the increased clarity of suicide risk assessment using a DSM-based SCS diagnosis would reduce legal challenges, promote education, and stimulate research for new treatments, all necessary to enhance and maximize suicide prevention.