The total is the highest since 2015 and represents an increase of 18 from the 219 suicide deaths recorded in 2020.
The Nisra figures show that in 2021, 176 (74.3%) suicide deaths were men and 61 were women.
Since 2019, the suicide rate has been increasing among both men and women.
The rate for males increased from 19.1 per 100,000 males in 2019 to 21.5 in 2021, while the corresponding rate for females increased from 6.0 per 100,000 females in 2019 to 7.3 in 2021.
Suicide deaths were highest in men between the ages of 25 and 29 and 45 and 49, while most suicide deaths in women were between the ages of 20 and 24.
Overall, according to Nisra statistics, in 2021 one in three suicide deaths was someone under the age of 30.
Northern Ireland had an age-standardised rate of 14.3 suicides per 100,000 population in 2021, higher than the 14.0 suicides per 100,000 population for Scotland and 10.5 suicides per 100,000 in England and Wales.
Nisra said cross-country comparisons are influenced by differences in the data collection and comparison processes used in different jurisdictions.
The Belfast Trust had the highest suicide rate with 17.9 deaths per 100,000 in 2021, followed by Western Trust (16.0 deaths per 100,000).
Northern Trust had the lowest suicide rate in 2021 at 10.4 deaths per 100,000.
In the most deprived areas of Northern Ireland, the suicide rate in 2020 was almost double that in the least deprived areas (19.7 deaths per 100,000 in the most deprived areas, 10.8 per 100,000 in the least deprived areas) .
The official UK definition of suicide includes deaths from external causes associated with willful self-harm and unspecified intent. It does not include deaths where the outcome was considered random.
In response to the figures, Professor Siobhan O’Neill, Northern Ireland’s mental health champion, tweeted: “We never forget these are the real people, with loving families and friends who are devastated.”
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