Teenage girls are about three times as likely as boys to attempt suicide for drug-related reasons, according to an analysis of emergency-room visits.

A government study also found boys are far more likely to attempt drug-related suicide in the month of December, while the suicide rate for girls stays fairly steady throughout the year.

The study, conducted by the Substance Abuse and Mental Health Services Administration, found an average of 178,423 emergency room visits a year from 2004 to 2008 for drug-related suicide attempts involving people age 12 or older. 

The study looked at the percentage and timing of such attempts among adolescents ages 12 to 17, adults ages 18 to 49 and adults age 50 and older. The study also tracked the number of visits each month to see if there was seasonal variation in the data.

Other research has suggested depression, which is a risk factor for suicide attempts, can worsen in the fall or around major holidays. But the study found that for the population as a whole, there was little seasonal variation in drug-related suicide attempts. The number of visits reported by emergency departments ranged from a low of 12,656 in February, or 7.1 percent of all drug-related suicide attempts, to a high of 16,812 visits in September, or 9.4 percent.

The picture was different for adolescent boys, age 12 to 17. The month of February had the lowest rate of drug-related suicide attempts, or 2.5 percent of an average year's total. The high was in December, at 18.9 percent. For girls, there was little variation month to month.

But the total number of drug-related suicide attempts by girls was 15,552 a year on average. For boys, that number was 5,283.

Related: Dr. Ablow  - Signs & Symptoms of Student Depression

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