Patients' recovery and non-recovery narratives after intravenous ketamine for treatment-resistant depression

Background

Intravenous (IV) ketamine is an effective therapy for treatment-resistant depression. A large database is confirmatory and steadily expanding. Qualitative studies can inform best practices and suggest new research directions. As part of a clinical trial designed to identify biomarkers of ketamine response, a qualitative study was conducted to characterize experiences with receiving infusions, recovering or not recovering from depression, and beliefs about why ketamine worked or did not work.

Methods

Adults with treatment-resistant depression received three IV ketamine infusions in a two-week period and were characterized as remitters or non-remitters via symptom reduction 24 h after the third infusion. Qualitative interviews of a subset of participants were audio recorded, transcribed verbatim, and coded using deductive and inductive methods. Themes were derived and compared across a broader construct of recovery status.

Results

Of the 21 participants, nine (43 %) were characterized as having experienced remission and 12 (57 %) non-remission. Of the 12 non-remitters, five were characterized as having experienced partial recovery based on their subjective experiences, reporting substantial benefit from ketamine infusions despite non-remission status based on scale measurements. Attributions for ketamine's effects included biological and experiential mechanisms. Among non-remitters, there was a risk of disappointment when adding another failed treatment.

Limitations

A more diverse sample may have yielded different themes. Different patients had different amounts of time elapsed between ketamine infusions and qualitative interviews.

Conclusions

Qualitative methods may enhance researchers' characterization of IV ketamine's impact on treatment-resistant depression. While requiring confirmation, patients may benefit from a preparatory milieu that prepares them for multiple recovery pathways; decouples the psychedelic experience from clinical outcomes, and addresses the potential risks of another failed treatment.