Depression is often concealed in the elderly as the "stiff upper lip" attitude can act as a disguise for the illness.

A new survey shows that 25 percent of people aged over 65 believe depression is a state of mind and not a mental illness. Photo: Getty Images

A recent survey found that a quarter of people over 65 believed that depression was a state of mind, not an illness.

This could signal a lack of understanding of depression, leaving many older people with the illness undiagnosed.

A new, free information leaflet 'Mind Yourself -- Depression in Later Life' is available through the company Lundbeck at (01) 468 900 to help older people who may have depression.