Lacking purpose in life and having few opportunities for personal growth may increase the risk of developing mild cognitive impairment (MCI), a frequent precursor of dementia, a study suggests.

These aspects of psychological wellbeing noticeably decline two to six years before memory loss and thinking problems are diagnosed, researchers found.

The study adds to mounting evidence linking psychological wellbeing to brain ageing, including the development of dementia.

Researchers tracked 910 people in Illinois in the US for an average of 14 years to assess whether they developed MCI or dementia.