Mental illness has become the drug industry's golden goose, a GP claimed as he cautioned against over-use of antidepressants.
Des Spence said the medication was prescribed "too easily" for too long and may have no benefit at all.
And he argued that the current definition of clinical depression - two weeks of low mood, even after bereavement - was too loose and led to "widespread medicalisation".
According to recent research, 75% of those who write such definitions have links with drug companies, he said.
His comments, published in an article for the BMJ, come after NHS figures revealed antidepressant prescriptions in the UK increased by 9.6% in 2011 to 46 million.
Dr Spence wrote: "Improving society's well-being is not in the gift of medicine nor mere medication, and over-prescribing of antidepressants serves as distraction from a wider debate about why we are so unhappy as a society. We are doing harm."
The Glasgow GP dismissed suggestions that the condition was under-treated, insisting such claims were based on research dating back to the 1990s which is no longer relevant.
While he acknowledged depression was an important illness from which "few of us are untouched", he warned against "medicalising normality".
The GP warned against "widespread medicalisation"
He wrote: "Mental illness is the drug industry's golden goose: incurable, common, long term, and involving multiple medications.
"This relation with industry has engrained a therapeutic drug mindset to treat mental illness.
"Today, the Centers for Disease Control and Prevention reports that 25% of US citizens have a psychiatric illness. Isn't this medicalising normality?"
Recent figures show high levels of depression cost the country almost £11 billion a year in lost earnings, demands on the health service and in prescribing drugs to tackle the problem.
Dr Spence said: "As a generalist prescribing antidepressants daily in primary care, I think that we use antidepressants too easily, for too long, and that they are effective for few people (if at all).
"But even questioning current care is considered "stigmatising" towards mental illness and "populist" anti-medicine rhetoric."
Meanwhile, he questioned the efficacy of antidepressants, citing a Cochrane review which found only one in seven people benefits from the medication.
This would mean millions of people were enduring at least six months of ineffective treatment, he concluded.
He added: "People who do not respond fare worse, with switches of medications and often multiple drug combinations."
But Ian Reid, professor of psychiatry at the University of Aberdeen, said claims relating to over-prescription required "careful consideration".
And he attributed the rise in prescriptions to small but appropriate increases in the duration of treatment, adding that increased use of antidepressants in other conditions "compounded misunderstanding".
"Antidepressants are but one element available in the treatment of depression, not a panacea," he wrote.
He added: "They can have harmful side effects, and they certainly don't help everyone with the disorder.
"But they are not over-prescribed. Careless reportage has demonised them in the public eye, adding to the stigmatisation of mental illness, and erecting unnecessary barriers to effective care."
Dr Spence is part of No Free Lunch, an organisation which encourages health care providers to practice medicine based on scientific evidence rather than allowing pharmaceutical promotion to guide clinical practice.