Suicidal ideation and a history of suicidal behavior are among the most salient short- and long-term risk factors for suicide (Beck et al. 1999; Brown et al. 2000; Kuo et al. 2001; Nordström et al. 1995). Many individuals die from their first suicide attempt (Isometsa 1998), which underscores the importance of assessing risk for this before people make that first suicide attempt. The terminology of suicidal outcomes has historically been diverse, inconsistent and ambiguous (O’Carroll et al. 1996; Posner et al. 2007). Terms that carry value judgments such as “failed attempt,” “suicide gesture,” “manipulative act”, “parasuicide”‚ “deliberate self-harm” and “suicide threat” (Crosby et al. 2011) obscure appropriate identification, and ambiguity and diversity in definitions may result in both over- and under-identification of high-risk individuals. In an effort to establish a meaningful common language for suicidal behavior, the United States Centers for Disease Control (CDC) has adopted terminology developed by a group of Columbia University suicidologists and recommends a standardized scale, the C-SSRS, to elicit the required information from respondents. The C-SSRS distinguishes between the following suicidal behaviors: (a) suicide‚ (b) suicide attempt‚ (c) interrupted attempt‚ (d) self-interrupted/aborted attempt‚ and (e) preparatory acts or behavior (Crosby et al. 2011) (Fig. 4.2). The U.S. Food and Drug Administration (FDA) adopted the C-SSRS categories of both behavior and the five subtypes of suicidal ideation, for the systematic, prospective monitoring of suicidal occurrences in clinical trials (See http://www.cssrs.columbia.edu). Self-injurious behavior without suicidal intent was also included in the list of outcomes in order to help distinguish suicide attempts from non-suicidal self-injurious behavior. These 11 categories are the FDA standard used for the detection of pre-existing risk and treatment-emergent suicidal ideation and behavior in all clinical trials involving drugs with central nervous system (CNS) activity (Food and Drug Administration 2012) (Fig. 4.1). Once one is assessing patients for treatment-emergent suicidal ideation and behavior, then it is also possible to detect beneficial effects of medications on ideation and behavior.
Fig. 4.2
CDC and Columbia uniform definitions
Suicide risk assessment instruments should aim to delineate suicidal ideation and behavior categories and their severity for more accurate determination of suicide risk. The following elements in a suicide risk assessment instrument are critical for the identification of high-risk individuals: a full range of suicidal behaviors and suicidal ideation.
4.3.1 The Full Range of Suicidal Behaviors
Historically a suicide risk assessments or screening queried solely about lifetime or recent suicide attempts, which resulted in the omission of other types of significant suicidal behaviors. Behaviors in which steps are taken imminently before a suicide attempt or suicide would have otherwise occurred (e.g., putting a noose around one’s neck and changing one’s mind, being rescued by another before running in front of traffic) and behaviors in preparation of suicide (e.g., buying a knife, collecting pills, writing a suicide note) are important subtypes of suicidal behavior that often go undetected by clinicians and gate keepers. This was confirmed in a 3,776 patient sample, in which attempts comprised only 13 % of reported suicidal behaviors, while the remaining 87 % consisted of the other three types (Mundt et al. 2011). While these events were rare (approximately one percent of 35,000 assessments), it is critical to more appropriately identify high-risk individuals. This is evidenced by the fact that, over a short-term follow-up, these other lifetime behaviors significantly predicted subsequent suicidal behavior, with all behaviors being similarly predictive. Furthermore, the total number of different suicidal behaviors increased risk (Posner 2012).
While a history of a suicide attempt is the most consistent predictor of future suicide attempts or death by suicide (Brown et al. 2000; Fawcett et al. 1990; Harris and Barraclough 1997; Malone 1995; Steer et al. 1988). Other categories of suicidal behavior also predict the risk of future suicide attempts including interrupted and aborted attempts and preparatory activities (Mundt et al. 2013). Finally, the most severe lifetime suicidal ideation predicts the risk for suicide.
Importantly, interrupted attempt, self-interrupted/aborted attempt, or preparatory acts or behavior constitute the majority of suicidal behaviors engaged in by high-risk individuals (Mundt et al. 2011) and are salient risk factors for suicide or suicide attempt, with similar risk ratios (Steer et al. 1988; Barber et al. 1998; Marzuk et al. 1997; Beck et al. 1999). Lastly, ideation is also a significant risk factor: the most severe lifetime suicidal ideation is a significant predictor for future suicide. Thus, it is critical that the full range of suicidal behaviors and ideation is assessed.
4.3.2 Intent to Die
With a history of a suicide attempt being the number one risk factor for future attempts or death by suicide, improved identification of past behavior is essential. Identification, in turn, critically hinges on the clear and accurate distinction between suicidal and non-suicidal behavior. Suicidal behavior is any type of self-injurious behavior (Crosby 2010), carried out with some intent to die. A critical criterion of suicidal behavior for its distinction from nonsuicidal self-injurious behavior is the presence of intent to die. Intent to die requires the desire to bring about one’s own death and is distinct from the motivations for desiring such an outcome (Hjelmeland and Knizek 1999). Such behavior is considered suicidal irrespective of the motivations surrounding the behavior, which are often affective in nature, such as ending emotional pain. A self-injurious behavior is suicidal if it is a result of any intent to die, and is strictly non-suicidal if it is not a result of any intent to die. Thus, the same behavior across individuals may be classified as suicidal or nonsuicidal depending solely on the presence or absence of intent to die. Intent to die need not be stated directly by the individual but may be inferred from additional facts such as high potential lethality of behavior (De Leo et al. 2004; Posner et al. 2011), the individuals’ perception of a behavior’s high potential lethality (Beck and Greenberg 1971), or additional data from informants (O’Carrol 1989) or medical records (Posner et al. 2007).
4.3.3 Distinction of Suicidal Ideation and Behavior
The prognosis and outcome of suicidal ideation and behavior are different. Suicide attempts are both less common and more closely related to suicide as an outcome. A widely used term “suicidality”, conflates ideation and behavior and FDA has recommended to discontinue its use. Distinct, non-overlapping definitions of suicidal ideation and suicidal behavior are critical for accurate assessment of prior ideation and behavior as predictors of future risk and for prospective detection of suicidal phenomena in the context of treatment. In a large multi-trial study lifetime severe suicidal ideation with at least some intent to die was associated with a five-fold increase in the risk of suicidal behavior on trial and a lifetime history of suicidal behavior without severe ideation was associated with a four-fold increase in risk of on trial behavior. Importantly, patients with a history of severe ideation and behavior were nine times more likely to have behavior during trial (Mundt et al. 2013). In an adolescent emergency department follow-up study, ideation was predictive of subsequent suicidal behavior even when a history of attempts was not predictive, reinforcing the need to identify suicidal ideation.
In general, the extant literature suggests separation of ideation and behavior because: (1) suicidal ideation and behavior do not always co-occur (Fawcett 1992), (2) gene variants associated with treatment-emergent suicidal ideation in clinical treatment trials of SSRIs appear to be unrelated to genes primarily associated with suicidal behavior (Laje et al. 2007; Meyer et al. 2010; Perlis et al. 2007; Perroud et al. 2009), (3) suicidal ideation is predictive of or a precursor to suicidal behavior (Posner et al. 2011; Kessler et al. 1999), and (4) ideation and behavior might be more predictive of suicide depending on other factors such as age (Brent et al. 1993; Fergusson et al. 2005; Lewinsohn et al. 1994; Pfeffer et al. 1993; Wichstrom 2000; Brown et al. 2000; Conwell and Thompson 2008; Vannoy et al. 2007; King et al. 2012). Moreover, suicidal ideation may add incremental validity to the prediction of future suicide attempts relative to a history of past suicide attempts alone (Horwitz et al. 2014). Treatment may affect risk of ideation without affecting risk of nonfatal suicide attempts or suicide. These findings confirm the importance of assessing suicidal ideation independently of suicidal behavior.
4.3.4 Suicidal Ideation
Suicidal ideation is a heterogeneous construct. The National Institute of Mental Health (NIMH) Developing Centers for Intervention and Prevention of Suicide specified that wish to die, thoughts of killing oneself, and intent to kill oneself constitute types of suicidal ideation (Brown et al. 2008). Suicidal ideation may be passive (i.e., having a wish to die as opposed to thoughts of killing one self) or active, which can range from range from non-specific thoughts of killing oneself to thoughts with a specific method or plan for killing (Brown et al. 2008). The distinction of passive and active suicidal ideation was first described by Beck et al. (1979) to separate thoughts of desiring one’s own death from thoughts of actively killing oneself (Beck et al. 1979). Intent to act demarcates the difference between thoughts of a suicide attempt where the person feels sure they would never act and where they believe they could act on those thoughts of killing themselves. A more severe stage is when the thoughts have a compulsive, or hard to resist quality, and the person may describe a struggle to resist the thoughts of suicide. The evidence base examining predictive properties of these ideation subtypes is growing (Mundt et al. 2013; Posner et al. 2011; Arias 2014; Hesdorffer et al. 2013; Katzan et al. 2013; Posner 2013) which was likely a result of the C-SSRS delineating ideation types more clearly.
4.3.5 Wish to Die
Thus, the PHQ-9 combines a large range of severity of suicidal ideation, blurring and eliminating the distinction between higher and lower risk ideation indicators, making the predictive value of this item poor.
Passive suicidal ideation includes any internal experience that indicates a wish or desire to die (“wish to die”) and excludes thoughts of being better off dead, thoughts of one’s own death, or that life is not worth living. This definition represents the consensus of the National Institute of Mental Health (NIMH) Developing Centers for Intervention and Prevention of Suicide conference (Brown et al. 2008). Evidence has shown that people with a high wish-to-die/wish-to-live index are six times more likely to die by suicide than those with lower indices (Brown et al. 2005). In turn, these research findings played a pivotal role in the development of the C-SSRS. Prior to this, assessment of suicidal ideation failed to distinguish true passive suicidal ideation (i.e., the wish to die) from other thoughts of death or dying that are not passive suicidal ideation and not predictive of future suicidal behavior. This historical muddling of definitions is evident in the Patient Health Questionnaire (PHQ-9), which spuriously equates thoughts of being “better off dead” with passive suicidal ideation, effectively eliminating the distinction between higher and lower risk indicators. Unsurprisingly, the predictive value of this item is poor. The observed point prevalence of suicidal ideation, behavior, or both was 6.2 % on the C-SSRS compared to 23.8 % on item 9 (the “suicide” item) on the PHQ-9 a nearly four-fold increase in false positive screens (Katzan el al. 2013). The Cleveland Clinic similarly compared the PHQ-9 suicide item to the electronic screening version of the C-SSRS, and found that the PHQ-9 yielded more than three times as many false positives as true positives (Katzan el al. 2013).
4.3.6 Intent to Act
Intent to act depends on the extent to which one is ready to act on thoughts of killing oneself. Suicidal thoughts without intent to act are characterized by having thoughts of killing oneself but not feeling that one might do anything about them. The distinction is clinically important because the presence of intent to act confers higher risk for subsequent suicidal behavior, as shown in a study of adolescent suicide attempters, where a lifetime history of severe ideation with at least some intent to die was associated with a 50 % increase in the risk of on-trial suicidal behavior (Posner et al. 2011; Currier et al. 2009).
4.3.7 Intensity and Worst-Point Ideation
In addition to types of suicidal thoughts, assessing their intensity and time frame is also very important. Although researchers and clinicians have assumed that one needs to query about current levels of ideation to identify risk, worst point lifetime ideation has been shown to be a better predictor of death by suicide (Beck et al. 1999). Unlike severity, ideation intensity is best seen as a continuous characteristic consisting of five dimensions: duration of thoughts, frequency of thoughts, controllability of thoughts, deterrents from acting on thoughts, and reasons for ideation. Duration of the most severe ideation predicts subsequent suicidal behavior among adolescents (King et al. 2012). In an adolescent emergency department follow-up study, it was demonstrated that duration of thoughts was predictive of subsequent suicidal behavior, while suicide attempts and lifetime attempts were not predictive, thus reinforcing the importance of ideation assessment (King et al. 2012). Significantly, all items on the C-SSRS intensity of ideation subscale (i.e.‚ frequency, duration, controllability, deterrents, and reasons for ideation) were shown to be significantly predictive of suicide on Beck’s SSI. Large trial data across multiple indications show that total score on ideation intensity incrementally is associated with a greater risk of suicidal behavior during trial‚ while minimal intensity of ideation was associated with a six-fold increase in the odds of suicidal behavior on-trial, very severe intensity was associated with a thirty-fold increase in risk (OR=34.39; 95 % CI: 9.23-128.09) (Posner 2014).
4.4 Instruments: Utility and Feasibility
Utilizing an evidence-based and research-supported instrument, such as the C-SSRS, for risk assessment can minimize false negatives and false positives, enable the redirection of scarce resources, and efficiently guide appropriate care to at-risk individuals. To determine whether a particular instrument is optimal and ideal for assessment, monitoring, or screening, consideration should be given to the following administration parameters: administration time, administration methods and delivery, the type of raters, and the level of training required for administration.
4.4.1 Administration: Time
The optimal administration time for any risk assessment instrument should be brief (minutes), which may be facilitated by the instrument’s structure. In particular, guided interpretation of patient responses during risk assessment in the form of a decision tree allows for briefer administration time and quicker and more reliable decision-making.
4.4.2 Administration: Methods and Delivery
The most common methods for suicide risk assessment by gate-keepers and clinicians involve a general interview and no systematic questions about ideation, behavior or family history of suicidal behavior. A much better approach involves systematic questioning guided by a checklist or rating scale (Malone 1995).
Self-report instruments have the advantage of making self-disclosure of sensitive issues easier. These types of instruments may facilitate the admission of suicidal ideation and behavior, or any suicide-related phenomena, which may be denied in an in-person, face-to-face interview. As mentioned previously, a telephone follow-up assessment, which used the C-SSRS, improved detection (58 %) of suicide attempts by more than 40 % when compared to hospital chart reviews (18 %) (Arias 2014).
Risk assessment instruments for suicide are available in a variety of paper and electronic formats. Importantly, innovative delivery formats enable a greater number of individuals to be screened, facilitating broader implementation. Timing of assessment is crucial after an at-risk patient is discharged from a hospital, particularly from a psychiatric inpatient unit, as there is an increased risk for suicide in the first week after discharge (Roy 1982).
4.4.3 Administration: Gatekeepers
Suicide risk assessment is not limited to medical settings, even though primary care physicians often see individuals shortly before they attempt suicide, but should include educational, religious, workplace, legal, and forensic settings. As such, settings may include diverse populations, it is crucial that nonmental health professions be able to ask appropriate screening questions. Training in the administration of a risk assessment tool enhances implementation efforts in these settings. In a juvenile justice setting nonclinician raters (gatekeepers) showed good inter-rater reliability when administering a structured risk assessment questionnaire to adolescent girls (Kerr et al. 2014). In the U.S. Marines, all support workers, such as chaplains, family advocacy workers and attorneys, are trained to be aware of suicide risk and warning signs and to administer and utilize the C-SSRS. In rural communities, where access to a mental health professional or practitioner may be limited, the ability of nonmental health professional gatekeepers to screen is essential.
4.4.4 Multiple Sources of Information
In many risk assessment contexts, situational factors render obtaining information directly from a patient impossible. Examples of clinical populations that are challenging span dementias, cognitive impairment, and autism. In all of these cases, collecting information from other reporters and its integration into an overall clinical picture is crucial. The ability of a risk assessment tool to obtain and integrate information from a variety of sources of information provides the necessary flexibility and accuracy.
4.4.5 Risk Management
Assessment scales should have operationalized thresholds that differentiate levels of risk and aid in determining patient disposition. A patient management protocol that specifies next steps after the risk assessment may include referrals to mental health professionals for low-to-moderate risk patients or hospitalization and suicide watch, for high-risk patients. Without a systematic assessment to determine suicide risk level that drives the next steps, providers are less able to properly triage patients. This can lead to overestimation of risk, or a tendency to err on the safe side, resulting in increased burden for mental health professionals, hospitals, and other healthcare facilities and diminished resources to offer the right quality of patient care for those who are most in need.
4.4.6 Generalizability
Suicide risk assessment instruments require parallel forms developed for specific populations. Modifications may include developmentally appropriate questions or addition of population-specific risk factors (e.g., the military) (Peñta and Caine 2006).
4.4.7 Triage
Operationalized thresholds that distinguish higher levels of risk are an essential component of assessment scales, so that appropriate triage steps can be taken. In cases of low-to-moderate risk, such steps may involve referral to mental health professionals for further evaluation, while high-risk cases may require hospitalization or suicide watch. In the absence of built-in thresholds that link to specific triage protocols, providers are forced to worry about every person screened. This could lead to problematic situations such as clinicians believing more patients require one-to-one observation than there is staff available to provide it. In other words, over-estimation of risk leads to misallocation of resources and poorer quality of care. Whether at a hospital or a correctional facility, it is essential for assessment administrators to have access to a screener with research-based next-step protocol, which will in turn impact care delivery and service utilization.
4.5 Risk Factors: Suicidal Behavior and Ideation-Specific Mediators and Moderators and Corresponding Instruments
A thorough evaluation of the benefits and risks of therapeutic interventions and suicide-related outcomes should include a consideration of known risk factors as well as mediating and moderating variables. Mediators are intervening variables that help clarify the nature of and represent potential mechanisms that underlie the relationship between independent and dependent variables. Moderators are characteristics that affect the direction and/or strength of the relationship between the independent and dependent variables. Suicidal behavior and ideation-specific mediators and moderators to be considered include: biological factors (genetic, stress responsivity, developmental anomalies, altered neural circuitry), psychological factors (aggressive and impulsive traits, negative inferential styles, cognitive rigidity, hopelessness, decision-making, problem-solving, mood regulation), psychiatric illness (e.g., major depressive episode), and social support systems (see Hudzik and Cannon, this volume). Knowing mediating and moderating relationships affecting the risk of suicide enhances the understanding of factors that play a role in mitigating or increasing that risk and creates a context for evaluating the effects of treatment. Table 4.1 lists examples of instruments assessing some of these risk factors.
Table 4.1
Select risk factors and associated instruments
Risk factor | Assessment instrument | References |
|---|---|---|
Aggression and impulsivity | • Barratt impulsiveness scale • Buss-Durkee hostility inventory • Brown-Goodwin aggression history (AGGHx) | |
Substance abuse | • Mental health screening form-III (MHSF-III) • Simple screening instrument for substance abuse (SSI-SA) • CAGE questionnaire (alcohol) • Drug abuse screening test (DAST) • Michigan Alcoholism Screening test (MAST), • Psychiatric research interview for substance and mental disorders (PRISM) | |
Hopelessness | • Beck hopelessness scale (BHS) | Beck et al. (1990) |
Distress/mental pain | • Mental pain scale • Self-defeating personality questionnaire (SDPQ) • Self-critical cognition scale • Self-derogation scale • The guilt inventory | |
Neurocognitive factors | • Iowa gambling task (decision-making) • Stroop task (interference scores; attention) (adapted) • Buschke selective reminding task (SRT) test (memory and learning) |
4.6 How Should Instruments Measure Suicide Risk: Characteristics Important for Detection and Prediction
Suicidal behavior occurs in many psychiatric disorders (e.g., depression, schizophrenia) and in many medical conditions (e.g., strokes, epilepsy, head injury and AIDS) (Harris et al. 1994). Thus, monitoring of suicidal ideation and behavior should be part of clinical practice for nonpsychiatrists including neurologists, internists and primary care physicians. In the evaluation of new medications that affect the brain and other systems such as endocrine, measuring the impact of new drugs on suicidal ideation and behavior has been made a requirement by the FDA for all clinical trials. For accurately assessing the comparable importance of risk and protective factors from a clinical and public health perspective.
Prior to FDA mandating prospective monitoring of suicide-related events in drug trials, all previous antidepressant, anticonvulsant‚ and other non-psychiatric trials were not set-up to adequately assess these events. Suicide risk analyses were based on spontaneously generated adverse events and the higher risk estimates from these analyses may have been a product of ascertainment bias rather than a reflection of a true association.
The choice of a suicide risk assessment instrument and interpretation of the results obtained from the assessment depend on the degree to which the instrument is able to capture concepts of interest (Fig. 4.1). From this point of view, an instrument which incorporates clear definitions and examples of behaviors that reflect those concepts minimizes variability in clinical judgment.
Science demands uniformity in measurement: moving away from a single instrument inherently degrades the precision of the signal, compounding existing imprecision across research sites and raters (Gibbons, 2010). The impact of imprecision grows when incidence rates are low, such as with death by suicide. At the same time, imprecision with low frequency events is incredibly problematic, as misclassification of one or two cases can have a profound impact on risk estimates and substantially alter conclusions. Even if you assume two measures are equally valid, more measurement variability still equals more noise. This has a particularly large impact when trying to combine studies. The 2012 FDA Guidance echoes this sentiment, stating that “the use of different instruments is likely to increase measurement variability… decreasing the opportunity to identify potential signals” that would inform future analyses and clinical trials. Uniform measurement with a validated instrument like the C-SSRS is crucial for prevention, research, and clinical practice.
Research has shown that systematic monitoring and consistent application of well-operationalized suicidal ideation and behavior criteria result in lower and more precise risk estimates. In a classic example of controversy surrounding safety of antidepressants, analyses commissioned by the FDA showed that consistent application of the C-SSRS’ empirically supported definitions of ideation and behavior led to significantly better estimates of risk, with 50 % fewer ascertained suicide attempts (Posner et al. 2007). Similarly, in a large nonpsychiatric trial with 14,000 subjects, systematic monitoring sourcing the C-SSRS revealed 12 suicidal adverse events (AEs) compared to 452 reported spontaneously (Posner January 2009). Reducing false positives is as important as identifying risk in the effort to improve detection and better allocate limited or scarce resources. An initiative organized by the CDC, Department of Defense, National Institute of Mental Health, and the Department of Veterans Affairs is recommending the C-SSRS as one of the consensus measures to be incorporated into large-scale biomedical studies involving human subjects to facilitate data sharing and comparison (http://www.phenxtoolkit.org).
Related posts:
Traumatic Brain Injury (TBI) and Post Traumatic Stress Disorder (PTSD) as Risk Factors for Suicidal Thoughts and Behaviors
Genetic Risk Factors for Suicidal Behavior
Suicide in the Second Half of Life: Cognition and Decision Processes
Experimental Pharmacologic Approaches for the Reduction of Suicidal Ideation and Behavior
Animal Models of Risk Factors for Suicidal Ideation and Behaviour
Treatment Emergent Suicidal Ideation and Behavior
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