Scientists have identified five different types of insomnia, a finding they say paves the way for more targeted treatments and therapies for those who experience the condition.

The subtypes are not based on sleep complaints, such as difficulty falling asleep or early morning awakening, but on differences between personality traits, responses to treatment, life history and risk of depression.

Researchers surveyed over 4300 participants from the Netherlands Sleep Registry, a database of volunteers, who filled out at least one of 34 questionnaires on personality traits, sleep, life events and health history.

In the findings, outlined in the Lancet Psychiatry, of the 1046 who completed more than 10 questionnaires, researchers classified insomnia into the following: