Short birth length ups risk of suicide attempts

By Anthony J. Brown, MD

NEW YORK (Reuters Health) - Male babies with a short birth length run more than double the risk of a violent suicide attempt as an adult, according to a Swedish study published in the Journal of Epidemiology and Community Health for February.

Catch up growth during childhood does not lessen the impact of short stature at birth, Dr. Ellenor Mittendorfer-Rutz, from the Karolinska Institute in Stockholm, and colleagues found.

Their study involved 318,953 men who were born in Sweden between 1973 and 1980 and followed to the date of attempted suicide, death, emigration, or through 1999.

Results showed that short babies of less than 47 cm in length, were more likely to attempt suicide as adults, no matter what height they reached in adulthood, compared with normal length babies.

Short birth length also more than doubled the risk of a violent suicide attempt as opposed to a non-violent one. A violent suicide attempt was defined as hanging, the use of a firearm or knives, jumping from a height or in front of vehicles, and drowning.

Short stature in adulthood also boosted the risk of suicide attempt. Men who were normal length babies, but who were short in adult life were 56 percent more likely than tall men to attempt to take their own lives.

The taller a man was, the less likely he was to attempt suicide, the investigators found.

Men who were born underweight (under 2500 grams), but who reached normal height were more than 2.5 times as likely to make a violent suicide attempt. And those who were born prematurely, and therefore short and underweight, were more than four times as likely to attempt violent suicide as those born after 38 to 40 weeks of pregnancy.

Mittendorfer-Rutz and colleagues suggest that the brain chemical serotonin may be involved in the results. Serotonin is crucial to brain development and low levels are important in impulsivity, aggression, and suicidal behaviour. Serotonin levels may be affected by premature birth and other factors restricting growth in the womb, they note.

SOURCE: Journal of Epidemiology and Community Health, February 2008.