The skunk working next to you at the office may have an explanation: he may be depressed! A team from Tel Aviv University, in a research published in the journal "Arthritis and Rheumatism", has found a connection between depression and lowered sense of smell.

"Our scientific findings suggest that women who are depressed are also losing their sense of smell, and may overcompensate by using more perfume. We also believe that depression has biological roots and may be an immune system response to certain physiological cues", said co-author Prof. Yehuda Shoenfeld, of the Sackler Faculty of Medicine at Tel Aviv University.
"Women who are depressed are also more likely to lose weight. With a reduced sense of smell, they are less likely to have a healthy appetite", he said.

Shoenfelds' work focuses on autoimmune conditions, like lupus, arthritis and rheumatism. About 1.5 million Americans experiencing lupus also have depression, and Shoenfeld shows that this is beyond an emotional reaction rather caused by a biological cause.

In lupus patients and other autoimmune conditions, the autoantibodies attack individuals's own immune system, an aberrant reaction inducing these conditions.

"We have found that, when generated, it (the autoantibody) weakens a person's sense of smell and can induce the feeling of depression", said Shoenfeld.

It has already been known that Alzheimer patients lose smell, but this is the first research connecting depression to smell in lupus patients.

"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", said Schoenfeld.

Other psychotic conditions, like schizophrenia, seem to have a biological cause.

"There may be an organic cause to these disorders, and if this is the case, clinicians might have to change their attitude about current therapies they use. 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. A standardized 'smell test' could be used by doctors to help diagnose depression as well as autoimmune diseases", said Schoenfeld.

The connection smell-depression could have marketing implications.

"The retail industry has learned that if it splashes good smells around, it can convince clients to buy more and invest more money. It certainly has an effect on one's mood", said Shoenfeld.