We’ve known for some time that if your patient has a parental history of a mood disorder or suicide attempt, his or her risk of a suicide attempt increases. A new study provides the best evidence of this to date, and adds some more information that might help us prevent bad outcomes.
From 1997 to 2005, researchers recruited 334 patients with mood disorders who were clinically referred to one of two academic clinics in Pittsburgh and New York City. They patients had an average of 2.1 children, for a total of 701 offspring. These offspring were then recruited into a long-term study. They were given a battery of standardized psychiatric interviews at baseline, and these evaluations were repeated annually for a mean follow up of 5.6 years. Researchers assessed for the presence of DSM-IV psychiatric disorders at each time point, and also administered a variety of symptom scales to measure symptoms of depression, hopelessness, impulsivity, aggression, and others.
The results can be a bit confusing, and in an effort to clarify, the authors use the term “probands” to refer to the 334 parents, as opposed to the term “offspring” to refer to the children. Over half of the probands, or 57.2%, had made suicide attempts at some point in their lives. (The lifetime prevalence of suicide attempts in the general population is about 5%, according to the National Comorbidity Study (Kessler RC et al, Arch Gen Psychiatry 1999;56(7):617–626). Of the 701 offspring, 73 (10.4%) made a suicide attempt. Offspring of probands who had made suicide attempts were about five times more likely to have made an attempt themselves than offspring of non-attempters. The authors did not mention whether there any completed suicides. The mean age of an offspring attempt was 20.1 years.
The question the researchers wanted to answer was whether certain factors could be identified that made an offspring’s suicide attempt most likely. The factors that most strongly predicted an offspring suicide attempt were the following:
• Offspring mood disorder at the time point just before a suicide attempt— which elevated risk 11-fold compared to those without a mood disorder at that time point.
• Offspring history of a prior suicide attempt, 5.7 times increased risk.
• Parental history of suicide attempt, 4.8 times increased risk.
• Offspring mood disorder at study entry, 4.2 times increased risk. of the salient secondary findings included the interesting fact that a parent’s suicide attempt conferred a higher risk of an offspring attempt independent of an offspring’s mood disorder. Also, there appears to be a role for “impulsive aggression”, which was measured with a couple of different self-report “hostility inventories”. High impulsive aggression scores in the offspring increased the likelihood of a mood disorder, which in turn increased the risk of a suicide attempt. Offspring age, sex, or bipolar versus unipolar disorder had no effect on risk of suicide attempts (Brent DA et al, JAMA Psychiatry 2014;epub ahead of print).
Although this large study doesn’t really provide any groundbreaking new information, it reinforces conventional wisdom that obtaining family histories is important. If your patient had a parent who attempted suicide, he or she is at nearly five times higher risk for their own suicide attempt—and other powerful predictors of attempts are having a mood disorder and a prior history of an attempt. Finally, probe for a history of impulsive aggression, which may be a red flag for a mood disorder more likely to lead to an attempt. Patients who have any or all of these risk factors should be treated more intensively—for example, more frequent visits, more family involvement, more school involvement, and therapy combined with medications.
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