French scientists have identified the absence of a molecule called “macrophage migration inhibitory factor,” or MIF, as a possible cause of depression. Increasing the amount of MIF in the brain may form the basis for new treatments for depression.

In April, a team of scientists headed by Carmen Sandi from the Laboratory of Behavioral Genetics announced they had noticed that when MIF was absent from the hippocampus of rats, the rats showed increased anxiety.

Scientists think the hippocampus is the area in the brain where memories are formed and new neurons are generated. New neurons are thought to play an important role in curbing anxiety. Without enough MIF in the hippocampus, fewer neurons are made, thereby increasing anxiety.

Many anti-depressants work by boosting neuron production. Using genetics and pharmaceuticals to manipulate MIF levels, the team found that lack of MIF, decreases the ability of anti-depressants to increase the production of neurons.

It will be years before scientists come up with an approved treatment for depression based on MIF. Until then, women who are still depressed after taking Prozac might want to consider the work of Andrew Herzog, a neuroendocrinologist at Beth Israel Deaconess Medical Center in Boston.

Herzog believes women become depressed due to an imbalance of estrogen and progesterone. He prescribes a skin cream containing progesterone for its calming effect and estrogen for lethargic depression.

Others might want to try vagal nerve stimulation. The vagal nerve connects the brain stem with the upper body (lungs, heart and stomach). To find out if seizures in epileptics could be reduced by implanting tiny pacemakers to the stimulate the vagal nerve scientists found that the epileptics got happy.

Since then, VNS has been studied in depressed patients. Forty percent experienced a substantial decrease in depression; 17% experienced complete remission.