The US suicide rate rose in 2021, particularly among young men, according to official data out Friday -- an increase that ends a two-year-decline.

The number of suicides rose from around 46,000 in 2020 to 47,650 in 2021, according to preliminary figures released by the Centers of Disease Control and Prevention (CDC).

The age-adjusted suicide rate per 100,000 people grew from 13.5 in 2020 to 14 last year. The most significant increase was seen among young boys and men between the ages of 15 and 24, where the rate rose eight percent.

In 2000, after a decade of decline, the United States recorded a recent low of 10 deaths by suicide per 100,000 people.

"One of the things that may have contributed to the decrease in the 1990s was the  advent of medications that help reduce risk for suicide," Jill Harkavy-Friedman of the American Foundation for Suicide Prevention, told AFP.

The rate then started growing -- potentially because of new warning labels attached to antidepressants, according to Harkavy-Friedman  -- until by 2018 it was 35 percent over 2000 levels.

Then, it fell five percent from 2018 until 2020.

According to Harkavy-Friedman, the recent fluctuations are difficult to interpret.

"We don't really know yet what the full implications of this kind of rise are," she said, adding it was necessary to look at patterns over the long term.

The role of the Covid-19 pandemic, in particular, is complex.

According to the AFSP, research has shown that "people tend to come together during traumatic events initially and this can serve as a protective factor against suicide, though this societal cohesion may not persist as time passes."

Data from 2021 shows that the suicide rate for men is four times higher than for women, which is in line with past trends.

Among the reasons put forward include the idea that men are more likely to use lethal means, and have more difficulty in seeking mental help.

This preliminary data does not yet provide a breakdown by ethnicity or income of the deceased.

According to the CDC, suicides are the second leading cause of death among those aged 10-34.

Recently, the United States introduced a simpler three-digit helpline (988) for people in distress, replacing the previous 10-digit number.

"We're very happy about 988, which is the new mental health crisis line, and the accompanying crisis services that goes with it, because this is going to bring options to people who feel so desperate and in such pain," said Harkavy-Friedman.