Suicide is the 11th leading cause of death in the United States (8th in men, 16th in women) [1]. In 2006, suicide was responsible for 33,300 deaths, with higher rates among whites, youths, and individuals more than 65 years of age [2]. Although no recent national estimates of the number of admissions to ICUs due to suicide attempts are available, in 2008, 376,306 people presented to an emergency department for treatment of self-harm, and 163,489 people were hospitalized due to self-inflicted injuries [1].

Although appraisals of suicide risk are incapable of absolute predictions of suicidal behavior, careful history-taking, detailed examination, and astute clinical judgment allow a comprehensive understanding and evaluation of risk factors, protective factors, and the interplay among them (Table 200.1).

The first set of factors is sociodemographic, including age, gender, race, marital status, and religion. In general, men are more likely to complete suicide, whereas women are more likely to make attempts [1,3,4]. White men are more likely to attempt suicide than nonwhites; among nonwhite populations, rates vary [1,3]. Suicide rates increase in two particular age distributions: late adolescence to young adulthood and older than age 65 [1,2,5]. In general, the suicide rate is greatest among divorced and widowed people, followed by single individuals, and married people [5]. The combination of age, gender, and marital status also plays a role; young widowed men have a particularly high rate of suicide [5].

Some evidence suggests that religious beliefs and the strength of one’s religious convictions protect against suicide; however, for some, religion may increase suicide risk. For example, an individual who believes he will be reunited with his lost loved ones when he himself dies may be comforted by the idea of dying. Thus, the various meanings religion can have in different people’s lives mandate careful exploration with the patient of the role of religion in death and suicide [5,6].

Psychiatric illness contributes significantly to the risk for suicide. Retrospective studies have identified one or more psychiatric disorders in individuals who have completed suicide or presented following a suicide attempt [7,8]. In addition, conditions often comorbid with psychiatric illnesses (e.g., substance use disorders) increase the risk for suicide. The presence of a past history of suicide attempts, suicidal thinking, self-injurious behavior, impulsivity, assaultiveness, and trauma (physical or emotional) is an important component of risk assessment. Whether a patient is in active outpatient psychiatric treatment—and compliant with it—is also critical. Psychological factors—coping skills, tolerance of emotions, personality traits, insight, and judgment—figure prominently in the estimation of how a patient handles stress.

The presence of a physical illness contributes to the risk for suicide, with the number of physical illnesses increasing the risk for suicide in a linear fashion [9]. Suicide risk is greater in patients with neurologic disorders (e.g., Huntington’s chorea, organic brain syndromes, multiple sclerosis, spinal cord injuries), and suicide attempts are more common in patients with epilepsy [5,10,11]. In addition, head trauma is associated with an enhanced risk for suicide, particularly when behavioral or cognitive sequelae result. Executive function deficits due to delirium, dementia, or mental retardation also contribute to the risk for suicide. Other illnesses of significance are listed in Table 200.1 [5,12].