The number of suicides in West Lindsey last year was the highest on record, figures show.
It reflects the trend seen across the UK, where the number climbed to its highest for three decades in 2018, driven by a significant rise in the male suicide rate.
Office for National Statistics figures show that 15 suicides were recorded in West Lindsey in 2018.
It was an increase on the eight recorded in 2017, the highest since comparable records began in 2002.
The suicide rate, which is measured across a three-year period, was 12.7 per 100,000 people in the area – above the rate across the East Midlands, at 8.7, and higher than the 11.2 average for the UK.
Across the UK, 6,507 suicides were registered last year, 12% more than in 2017.
Of them, three-quarters were men, at a rate of 17.2 per 100,000,which the ONS said this represented a “significant increase from the rate in 2017”.
It added that the exact reasons for the rise are unknown, but changes made in the last year to the way coroners record such deaths may be a factor.
In July 2018 the standard of proof used by coroners to determine whether a death was a suicide was lowered.
Samaritans chief executive Ruth Sutherland said: “It is extremely worrying that, for the first time in five years, the suicide rate in the UK has increased, with 686 more deaths than in 2017.
“There has also been a significant increase in the suicide rate in young men since 2017. Significantly, more men aged 45-49 took their own lives also, and middle-aged men remain the group at greatest risk of suicide.”
The figures show the highest rate of suicide across the UK by age in 2018 was among 45 to 49-year-olds, a rate of 27.1 deaths per 100,000 males.
Nick Stripe, from the ONS, said: “We saw a significant increase in the rate of deaths registered as suicide last year, which has changed a trend of continuous decline since 2013.
“While the exact reasons for this are unknown, the latest data show that this was largely driven by an increase among men who have continued to be most at risk of dying by suicide.
“We will continue to monitor the recent increase, to help inform decision-makers and others that are working to protect vulnerable people at risk.”
The figures cover all deaths from intentional self-harm for people over the age of 10 and deaths where the intent was undetermined for those aged over 15.