When transforming the effect size of suicide risk associated with family history and its distribution in the cases of completed suicide into the population attributable risk, a family history of completed suicide accounted for 2.25% of the total suicides while a family history of hospitalized psychiatric illness accounted for 6.80% of the suicides (Qin et al., 2002). This means that if all individuals had a similar risk to those not exposed to family history of completed suicide or psychiatric disorders, the proportion of suicides that would be prevented is about 9.1%, of which 2.3% would be attributed to family history of suicide. The attributable risk associated with family history is higher for younger people. For instance, Agerbo et al. (2002) estimated that, for people under age 21, about 12.8% of suicides would not occur if exposure to suicidal death and psychiatric illness in parents were eliminated. The estimations of attributable risk in these two studies were made after the adjustment for each subject's own psychiatric admission history and other risk factors and would be larger if exposures in other relatives, family history of suicide attempts and family history of psychiatric disorders that did not result in admission to hospital were included.
Therefore, inclusion of familial suicide history in the assessment of suicide risk is important, even though people with a family history of suicide are only a small proportion of the total number of people who committed suicide. Also, the importance of family psychiatric history should not be disregarded, because it can help to identify people vulnerable to mental disorders associated with suicide. These factors are essential in prevention programs targeting adolescents and young adults and might apply to the general population. Preventive strategies should be aimed at the early recognition and optimal treatment of mental illness. Supportive interventions may be indicated for the families of suicide victims.
Suicide is the complex result of many factors. Even if individuals have a family history of both suicide and psychiatric illness, they are not doomed. Having a family history, like exposure to any other risk factors, indicates that a person is at an increased risk in comparison to people without such exposures; it cannot predict if the person is destined to attempt or complete suicide. Psychiatrists, psychologists and all health-related professionals need to present appropriate interpretations of research findings to individuals who become depressed due to the awareness of their family history to help them restore their confidence in life.