The overall suicide rate in the UK increased from 11.1 to 11.8 per 100,000, the ONS said, while the highest suicide rate was among men aged 30 to 44 at 23.5 deaths per 100,000.
Among women, the highest rate of suicide was among 45 to 59-year-olds at 7.3 per 100,000. In 2011, additional guidance was given to improve the classification of narrative verdicts at inquests in England and Wales.
A narrative verdict is a long-form, factual record of how and in what circumstances a death occurred and is used as an alternative to short-form verdicts such as suicide.
There had been concerns among researchers that these classification rules forced the ONS to record probable suicides as accidents. So in 2011, the ONS identified common phrases used by coroners to terms allowed for the classification of intentional self-harm.
This additional guidance could have resulted in an increased number of narrative verdicts coded as intentional self-harm in 2011, the ONS said, which in turn could have contributed to the increase in the suicide rate.