Deep brain stimulation may provide long-term benefits in treatment-resistant depression

Key takeaways:

• Sixteen adults with treatment-resistant depression underwent deep brain stimulation and were monitored for up to 11 years.
• Response and remission rates were 62.5% and 43.75%, respectively, from year 2 forward.

Subcallosal cingulate gyrus deep brain stimulation was generally safe and significantly improved depressive symptoms in patients with treatment-resistant depression, with results sustained up to 7 years, according to research.

“It is estimated that one-third of patients with major depressive disorder will have treatment-resistant depression, and up to 20% will present a chronic course,” Carlo Alemany, MD, from the department of psychiatry at Hospital de la Santa Creu i Sant Pau in Barcelona, Spain, and colleagues wrote in The Journal of Clinical Psychiatry.

Researchers sought to expand on previous findings and examine long-term safety and efficacy of subcallosal cingulate gyrus deep brain stimulation (SCG-DBS) in patients with treatment-resistant depression (TRD).

They conducted a study of 16 individuals (mean age at surgery, 48.6 years; 75% women) with TRD and either major depressive disorder or bipolar disorder. Participants were currently in a depressive episode lasting at least 12 months and received SCG-DBS between January 2008 and June 2017, with follow-up through June 2019.

Twelve patients had SCG-DBS during a clinical trial, while the remaining four underwent the procedure as part of a compassionate treatment program.

Researchers defined response as at least a 50%reduction from baseline in the 17-item Hamilton Depression Rating Scale (HAM-D17) score and remission asa HAM-D17 score of no more than 7. Researchers used the Illness Density Index (IDI) as a longitudinal measure of treatment effects.

Following post-surgery stabilization, defined as a HAM-D17 score less than 8 for at least 3 months, patients were seen by a psychiatrist every 2 weeks then every 1 to 2 months from the second year through the last follow-up.

According to results, the mean HAM-D17 score decreased more than 50% in the first year following the procedure, with steady improvement as high as 85% reduction by year 7. From year 2 to the end of follow-up, response and remission rates were 62.5% and 43.75%, respectively, while the rates over the final 2 years of follow-up were 75% and 50%, respectively.

Although the procedure was generally safe and well-tolerated, researchers reported 122 adverse events, 25 of which were related to SCG-DBS. There were two patient deaths by suicide long after surgery.

Researchers also noted that IDI curves indicated sustained clinical improvements, measured with HAM-D17 and Clinical Global Impression, and sustained functioning improvement via Global Assessment of Functioning scores.

“The pragmatic results presented here provide evidence for the long-term efficacy and safety of SCG-DBS as a viable strategy for patients with the most severe and refractory forms of both unipolar and bipolar TRD,” Alemany and colleagues wrote.