New research suggests adolescents who use hormone-based contraception are particularly at an increased risk of suffering from depression.

The use of hormonal contraception such as the the pill has been linked to an increased risk of depression in a Danish study of a million women.

Compared with non-users, women and teenage girls aged 15 to 34 who used hormonal contraception had a 1.23 times higher risk of being diagnosed with depression, especially adolescents, according to a paper published in the journal JAMA Psychiatry.

Reseachers at the University of Copenhagen in Denmark analysed health registry data of one million Danish women from 2000 and followed them up after an average of six years.

Of the 55 per cent of those who used hormonal contraception, there were just over 23,000 first diagnoses of depression at the time of follow up.

More than 133,000 had received their first prescription of antidepressants.

The highest risk of depression was among the adolescent girls, who had a 1.8-times higher risk of first use of an antidepressant.

The risk varied slightly among the different types of hormonal contraception, but the risk was three times higher among those who used non-oral products, such as progestogen implants.

Few studies have quantified the effect of low-dose hormonal contraception on the risk for depression, but study author Ojvind Lidegaard says their research warrants the need for further studies into the potential adverse effects of the pill.

"Use of hormonal contraceptives was associated with subsequent antidepressant use and first diagnosis of depression at a psychiatric hospital among women living in Denmark.

"Adolescents seemed to be more vulnerable to this risk than women 20 to 34 years old," Lidegaard said.