Treatment-resistant depression may yield to combinations of medications already in clinical use

New research published in JAMA Psychiatry indicates that combining medications already in clinical use may offer an effective approach for treating treatment-resistant depression, a condition affecting a significant portion of patients unresponsive to standard therapies.

Researchers analyzed 26 randomized controlled trials comparing intravenous ketamine with controls, finding that ketamine provides rapid relief of depressive symptoms and suicidal ideation in the short term, with effects diminishing over weeks. Both ketamine and esketamine, a nasal spray form approved by the FDA, showed similar efficacy in rapidly reducing depression and suicidal impulses.

Additionally, a meta-analysis of 22 studies examined the effectiveness of combining antidepressants with antipsychotics in patients with treatment-resistant depression. The study identified certain antipsychotics, such as lumapeterone, as significantly more effective in reducing symptoms. However, these medications were also associated with higher discontinuation rates due to side effects.

Why It Matters

This development matters because a substantial percentage of adults with depression do not respond to conventional treatments, leaving them at risk of ongoing suffering and increased suicide risk. The findings suggest that existing drugs, when used in combination, could expand treatment options and improve outcomes for these patients, potentially reducing the burden on mental health services and improving quality of life.

Background

Major depressive disorder affects millions globally, with approximately one-third of adults not responding to initial antidepressant therapies. Prior approaches have included newer medications like ketamine and esketamine, which have shown rapid effects but limited long-term data. These recent studies build on existing evidence, exploring how combinations of drugs already approved for other uses might be repurposed to treat resistant cases.

“At least one-third of adults with depression do not respond to at least two trials of conventional antidepressant therapies. These patients are considered to have treatment-resistant depression, and alternative therapies should be considered.”

— T. Greg Rhee, UConn School of Medicine

“These studies could potentially guide practicing psychiatrists and other clinicians to consider these new approaches of modalities for patients with moderate to severe depression, who did not previously respond to conventional antidepressant therapies.”

— T. Greg Rhee, UConn School of Medicine

What Remains Unclear

It remains unclear how long the benefits of these combination therapies last, their safety profiles over extended periods, and which specific patient populations will benefit most. Further population-level studies are planned to evaluate effectiveness and safety more comprehensively.

What’s Next

Next steps include larger-scale epidemiologic studies to confirm these findings, long-term safety assessments, and potential clinical trials to establish standardized protocols for combining these medications in treatment-resistant depression.

Key Questions

Can existing medications now be used to treat resistant depression?

While the research is promising, these findings are preliminary. Clinicians may consider these options, but formal guidelines and further evidence are needed before widespread adoption.

Are there risks associated with combining these medications?

Yes, some combinations, especially involving antipsychotics, can have significant side effects, and discontinuation rates due to adverse effects vary. More research is needed to assess long-term safety.

How soon might these findings influence clinical practice?

It could take several years of further research, including clinical trials, before these approaches become standard practice, pending regulatory review and guideline updates.

What types of patients might benefit most from these treatments?

Patients with moderate to severe depression who have not responded to at least two conventional antidepressant trials are the primary candidates for these combination therapies, pending further validation.