Researchers have carried out a study and found that women, who wear strong perfume are clinically depressed as they gradually become insensitive to smell, The Daily Telegraph reported on Saturday.

"Our scientific findings suggest that women who are depressed are also losing their sense of smell, and may overcompensate by using more perfume," lead researcher Prof Yehuda Shoenfeld of Tel Aviv University was quoted as saying.

According to the researchers, certain diseases cause the body to attack the olfactory system which in turn governs the ability to detect smells. "This means an impaired sense of smell could be a pointer to other serious conditions."

Prof Shoenfeld has suggested that depression could have a biological cause rather than a psychological disorder.

"We also believe that depression has biological roots and may be an immune system response to certain physiological cues."

In fact, the team looked at the links between depression and autoimmune conditions such as lupus, arthritis and rheumatism before coming to the conclusion.

The findings can be applied more widely than just to patients suffering with autoimmune disorders, according to the researchers.

"People who are depressed seem to respond well to aromatherapy. Certain smells seem to help them overcome the effects of the biological factors, suggesting that depression may have a biological cause.

"I think that science is able to show that aromatherapy might not be just for quacks. After all, some of these remedies have been used since the time of the Egyptians to treat organic diseases," Prof Shoenfeld said.

The team has also recommended that a 'smell test' could be used by doctors to help diagnose depression and autoimmune diseases.

Other studies have questioned if depression is a result of a reduced ability to smell rather than the other way around as the condition is also linked to weight loss as people lose their appetite.