People born in the spring or early summer face an increased risk of suicide, UK researchers suggest.
Seasonal links have been made to a number of diseases
A study of 26,916 suicides in England and Wales found babies born in April, May or June had a 17% higher risk of suicide than those born in the autumn.
The team suggested the increased risk reflected the fact that more people with alcoholism, depression and mood disorders are born in these months.
The research is published in the British Journal of Psychiatry.
Scientists have established seasonal birth trends for a number of diseases including some cancers, heart disease and brain tumours.
Other research has found more patients with schizophrenia, brain degenerating disease Alzheimer's, epilepsy and sleep disorder narcolepsy are born in December than any other month.
Equally, mental illnesses like depression and mood disorders and alcohol dependence are more frequent among those born during the spring and summer.
And 10% of suicides in England and Wales occur among people with these disorders.
The joint team from St Helen's and Liverpool University and the Institute of Child Health at University College London wanted to see whether there was a link between the two.
They analysed information on all deaths from suicide and undetermined injury reported between 1979 and 2001 in what they say is the biggest study of any possible link to suicide of this kind.
Among women, nearly 30% more suicides were committed by people born in the spring while among men the rate was nearly 14% higher than those born in the autumn.
Overall, the risk for people born in spring to early summer was increased by 17%.
The authors said: "Our results support the hypotheses that there is a seasonal effect in the monthly birth rates of people who kill themselves and that there is a disproportionate excess of such people born between late spring and midsummer compared with the other months."
Research leader Dr Emad Salib, consultant psychiatrist and senior lecturer at Liverpool University, said it could be that the baby's health prospects are linked to its seasonal experiences in the womb.
"As the baby is developing the brain is very sensitive to any change in maternal state, like infections and even temperatures.
"This can affect the way that cells in the brain are arranged.
"We are born all the same but some of us are more vulnerable than others to certain diseases.
"Some of us will get away with it, but some of us may end up falling victim to disease and committing suicide."
The researchers hope that their paper will open up new strategies for research into the causes of suicide and prevention.
Dr Mike McClure, suicide expert and director of public education at the Royal College of Psychiatrists, said the theory was a very plausible one.
He said: "When we are talking about suicide we are talking about a complex set of biological and social factors which interact in a very complex way.
"This work looks at the possible biological factors.
"There may be some behavioural conditions that differ in the mother during the gestational period that influence the child.
"All sorts of things could be very different from a seasonal perspective and that could influence whether the child or adult is more likely to be susceptible to depression or alcoholism for example."