Brain zapping may treat severe depression

Deep brain stimulation can provide long-lasting benefits for patients suffering from severe, treatment-resistant depression, a study has found.

Researchers from University of Freiburg and University Hospital Bonn in Germany used thin electrodes to stimulate a deep seated part of the reward system in the brains of 16 patients.

This led to a significant reduction of ratings of depression severity in all patients, it was reduced by half on average, according to a study published in the journal Neuropsychopharmacology.

For half of the study participants it was even reduced below the level regarded as the threshold for a depression requiring treatment.

Most of the patients experienced those positive stimulation effects within the first week, and they lasted throughout the course of the one-year study.

"The most compelling outcome from the study is the sustained efficacy in very severely ill patients," said Thomas Schlapfer, from University of Freiburg.

"Most treatments in psychiatry cease to be efficacious after moths and years, we demonstrated for the first time in demonstrating in a relatively large-scale study that deep brain stimulation is a real option for those patients suffering from treatment-resistant, severe depression," said Schlapfer.

An estimated 10 to 30 per cent of all people with recurring depression do not respond to approved treatments. Deep brain stimulation could be a treatment option for some of these patients.

The 16 participants in the study had suffered from severe depression for eight to 22 years and had previously undergone an average of 18 drug therapies, 20 electroconvulsive therapies, and 70 hours of psychotherapy -- without success.

Researchers implanted the deep brain stimulation systems in the patients medial forebrain bundle of the brain and used them to stimulate the medial forebrain bundle.

This brain region is involved in the perception and regulation of pleasure and reward and is thus also significant for motivation and the perceived quality of life.

The doctors evaluated the success of the therapy monthly with the help of the established Montgomery-Asberg Depression Rating Scale (MADRS), which scores of ten study participants already decreased significantly within the first week and remained at a low level.

All study participants reacted to the stimulation in the course of the study. Eight of the 16 patients had a MADRS score of under 10 points at the end of the study and thus were regarded as non-depressive.

"Our patients had struggled with severe depression for years with no signs of improvement," said Schlapfer.

"Deep brain stimulation brought most of them significant relief within days, which lasted throughout the course of the therapy. Other forms of treatment like medication and psychotherapy often lose their effectiveness over the course of time," he said.

"We know from a pilot study that the stimulation of this brain region is very promising and we are delighted about the replication of these significant effects," researchers said.