Deep brain stimulation is known to help in treating depression. New study shows that the therapy targeted to an area of the brain known as Brodmann Area 25 provides noticeable improvement in among patients who are highly treatment resistant.
In the study conducted at three research facilities in Canada, Dr. Andres Lozano and Dr. Helen Mayberg sought to build upon an earlier study by them.
They enrolled 21 patients who on average had suffered from depression for 20 years, had tried in excess of 16 depression medications and were considered disabled or unable to work at the time of enrollment.
At one year, 62 percent of all patients in the study had a 40-percent reduction in symptoms and 29 percent experienced a 50-percent reduction in symptoms as measured against their baseline which was established using the Hamilton Rating Scale for Depression.
"The reduction in depression scores is clinically significant as these patients had previously tried multiple medications, psychotherapy and/or electroconvulsive therapy (ECT) without success," said Dr. Andres Lozano, neurosurgeon at Toronto Western Hospital, author of the paper and a primary investigator in the study. "To see 62 percent of the patients in this study respond at one year gives us hope that this research may lead to a therapy for this hard-to-treat patient population."
Patients in the study were also evaluated using a Clinical Global Impression of Severity (CGI-S) rating scale that measures the severity of their illness. Before DBS, 70 percent of the patients were categorized as severely or extremely ill. After 12 months of DBS, over 80 percent of the patients experienced improvement and none of the patients were rated as severely or extremely ill.
Additionally, study results announced earlier at the American Psychiatric Association annual meeting reported that eight of the study patients returned to daily life activities such as work, school and sustaining relationships with family and friends, and two patients were considered to be in remission.
Participants in the St. Jude Medical-sponsored study featured in the Journal of Neurosurgery were implanted with the Libra™ DBS system which delivers mild pulses of current from a device implanted near the collarbone to small electrical leads placed in the subcallosal cingulate (SCC) area of the brain, a structure within Brodmann Area 25.
"These findings are significant as they confirm the basis on which we established the BROADEN pivotal study," said Rohan Hoare, president of St. Jude Medical Neuromodulation Division. "These results add to the growing evidence suggesting that DBS therapy may help patients who currently don't have an adequate treatment option in managing severe depression."
St. Jude Medical is currently conducting a large multi-center pivotal study at up to 20 facilities in the U.S. and internationally under a U.S. Food and Drug Administration (FDA) Investigational Device Exemption.