In a systematic review (meta-analysis), Harris and Barraclough9 abstracted 249 reports from the medical literature regarding mortality associated with mental disorders. They compared the number of suicides in patients with mental disorders with those in the general population.
The standardized mortality ratio (SMR) is a measure of the relative risk of suicide for a particular disorder compared with the expected rate in the general population (SMR of 1). The SMR was calculated for each disorder by dividing observed mortality by expected mortality (Table 2). The highest relative risk for suicide was associated with eating disorders. The SMR for eating disorders was significantly higher than that for major affective disorders and substance abuse disorder.
Virtually all psychiatric disorders, except mental retardation, are associated with an increased risk of suicide. The importance of making an accurate psychiatric diagnosis, one of the most important indicators of risk for suicide, is essential to competent suicide risk assessment.10
Medical and psychiatric comorbidities
Comorbidity is an independent suicide risk factor. Physical illness, especially in the elderly, is associated with suicide risk. Recognizing specific medical conditions that are associated with increased risk of suicide aids the clinician’s suicide risk assessment. Quan and colleagues11 found that older adults with mental disorders and coexisting cancer, prostatic disorder (excluding prostaticcancer), or chronic pulmonary disease were more likely to complete suicide than those without the medical illness. HIV/AIDS, malignant neoplasms as a group, head and neck cancers, Huntington chorea, multiple sclerosis, peptic ulcer, renal disease, spinal cord injury, and systemic lupus erythematosus are all associated with increased risk of suicide.12
Psychiatrc patients often present with more than 1 psychiatric disorder. For example, a patient with bipolar disorder may have borderline personality disorder or may be a substance abuser. Beautrais and colleagues13 found that individuals who made serious suicide attempts had high rates of comorbid mental disorders. These investigators compared 302 people who had made serious suicide attempts with 1028 randomly selected participants. The risk of suicide increased with increasing comorbidity: patients with 2 or more disorders had an 89.7 times higher risk for suicide than those without a psychiatric disorder.
Using a case-control design, Hawton and colleagues14 assessed 111 patients who had attempted suicide (72 female and 39 male). More patients with comorbid disorders had made previous and repeated attempts during the follow-up period. Comorbidity of Axis I disorders and personality disorders was present in 44% of patients.
Findings from a national population survey of 5877 respondents between 1990 and 1992 showed that a dose-response relationship existed between the number of comorbid psychiatric disorders and suicide attempts.15
In a prospective cohort study of 7968 deliberately self-harming patients, Cooper and colleagues16 found that the risk of suicide was approximately 30-fold higher than in persons in the general population during a 4-year follow-up period. Suicide rates were highest within the first 6 months after the initial self-harm, and female patients, in particular, were at high risk for suicide. The investigators underscored the importance of early intervention following self-harm.
In a follow-up study of 11,583 patients who presented to a hospital after DSM between 1978 and 1997, Hawton and colleagues17 found a significant and persistent risk of suicide. In this study, the risk was far higher in men than in women. Suicide increased markedly with older age at initial presentation.
Fawcett and colleagues18 identified short-term suicide risk factors from a 10-year prospective study of 954 patients with major affective disorders that were statistically significant for suicide within 1 year of assessment. The risk factors included panic attacks, psychic anxiety, loss of pleasure and interest, moderate alcohol(Drug information on alcohol) abuse, diminished concentration, global insomnia, and depressive turmoil (agitation). Clinical interventions directed at treating the anxiety-related symptoms in patients with major affective disorders can rapidly diminish suicide risk.19