Electroconvulsive therapy, previously known as “electric shock treatment” is a method that can help patients combat severe depressions that no other treatment can alleviate. Lund University researcher Johan Hellsten has now shown in animal experiments that electroconvulsive therapy leads to new generation of nerve cells and blood vessels in precisely those parts of the brain that are affected in patients with depression. This may explain how electroconvulsive therapy makes the disease recede.
We now know that a deep depression not only causes patients great suffering but also leads to measurable changes in the brain. It has been shown, for instance, that the hippocampus, an area associated with both the memory function and emotions, is smaller in volume in depressed patients. The longer the depression has lasted, the smaller the hippocampus becomes.
For several years, Johan Hellsten, under the direction of the psychiatrist Anders Tingström at the Lund University Wallenberg Neurocenter, has studied electroconvulsive therapy in experiments with rats. On the one hand, he has shown that rats exposed to stress hormones evince a reduction in the generation of new nerve cells and, on the other hand, that electroconvulsive therapy can counteract the negative effects of the stress hormone and re-initiate the generation of new nerve cells. Electroconvulsive therapy also increases the production of blood vessel cells (endothelial cells) and the number of blood vessels in the relevant parts of the brain.
“These studies are the first in the world to show increased production of blood vessels in connection with anti-depressive treatment,” says Johan Hellsten.
Better blood supply to those parts of the brain that are most affected by a depression should be beneficial to the patient, according to the Lund researchers. It should thereby be possible to counteract the shrinkage caused by depression. The blood-vessel forming endothelial cells also have other functions that can be useful: they secrete growth factors that promote the growth of nerve cells, for example.
The greatest objection to electroconvulsive therapy in psychiatric circles has been that the treatment can affect the memory. On the other hand, so do both high doses of sedatives and the depression itself. In the case of electroconvulsive therapy, moreover, it seems largely to be a matter of fleeting disturbances of the most immediate memories.
“New knowledge about the positive effects of electroconvulsive therapy can lead to a greater use of the method. But it can also help in the development of new, more effective anti-depressive drugs,” Johan Hellsten asserts.