Dutch scientists say this is because antidepressants cause "dry mouth" by curbing the production of saliva.

In recent years there has been both improved detection of depression and the "almost universal application" of antidepressants for treating it, the scientists write in the journal General Hospital Psychiatry.

Symptoms go unrecognised

But the dry mouth effect of the medication "often goes unrecognised by physicians or dentists." Instead, dentists often assume that cavities or infections are the result of poor oral hygiene.

Patients, they say, should be told about the dental risks involved in using antidepressants.

The researchers also recommend: "Prevention should be incorporated in the clinical management of depressed patients. Clinically, complaints of oral dryness should be elicited at every stage of antidepressant treatment. In cases of long-term treatment, attention to the oral health of the patient should be part of routine clinical practice."

Saliva is vital

Saliva is needed both to clean the smooth surfaces of the teeth and to "remineralize"' them.