Professor Gordon Parker of the University of New South Wales wrote in the British Medical Journal that almost all people experience symptoms such as "feeling sad, blue or down-in-the-dumps" at some time in their lives. However, that's not the same as clinical depression.
He conducted a 15-year study of 242 teachers and found that more than 75% of them met the current criteria for depression. Parker described depression as a "catch-all" diagnosis driven by clever marketing, BBC News reported.
"Over the last 30 years the formal definitions for defining clinical depression have expanded into the territory of normal depression, and the real risk is that the milder, more common experiences risk being pathologised," Parker wrote.
However, the same issue of the British Medical Journal featured an article by another psychiatrist who contradicted Parker's opinion. Increased diagnosis of depression has helped prevent suicides and reduced the stigma of mental illness, Prof Ian Hickie wrote.