Twins May Harbor Suicide Protection

A review of death records for nearly 22,000 twins in the Danish Twin Registry reveals that twins appear to be less likely than the general public to commit suicide.

Researchers at the Center for Population Studies at the London School of Hygiene and Medicine looked at same-sex twins born from 1870 to 1930 who died between 1943 and 1993. Of the 21,653 twins alive at the study’s inception, 13,318 died during the specified time period. The researchers then calculated an expected number of suicides for the twin population using observed suicide rates for the Danish population.

The report appeared in the August 16 British Medical Journal.

The researchers, led by Cecilia Tomassini, M.D., found that in general, the twin cohorts had a mortality pattern that was similar to that of the general population. However, the twins had a significantly lower rate of suicide, with only 211 observed suicides compared with the calculated expectation of 293 suicides. Suicide rates for twins were consistently lower for both men and women and consistent across all birth cohorts. In addition, the suicide rate was similar between identical and fraternal twins.

The researchers suggest that strong family ties reduce the risk of suicidal behavior and that those ties are inherently greater in twins.

The study, “Risk of Suicide in Twins: 51-Year Follow-Up Study,” is posted on the Web at www.bmj.com/cgi/content/full/327/7411/373. ▪