Association of anhedonia and suicidal ideation in patients with treatment-refractory depression after intravenous ketamine infusions

Abstract

Objectives

Accumulating evidence suggests that the effects of ketamine administered intravenously at subanaesthetic doses on both anhedonic symptoms and suicidal ideation occur independently of depressive symptoms in major depressive disorder (MDD) and bipolar disorder (BD). This study sought to determine the relationship between anhedonia and suicidal ideation after serial ketamine infusions.

Methods

A total of 79 subjects with either treatment-refractory MDD (n = 60) or BD (n = 19) were included in a clinical ketamine study. The Montgomery–Åsberg Depression Rating Scale (MADRS) anhedonia factor and the first five items of the Scale for Suicidal Ideations (SSI-Part I) were used to assess anhedonia symptoms and suicidal ideation, respectively.

Results

At baseline, anhedonia, as measured by the MADRS, was not significantly associated with suicidal ideation or specific suicide-related ideation as measured by SSI-Part I (all p’s > 0.05). Only the ‘wish to die’ and ‘desire to make a suicide attempt’ items were positively associated with anhedonia at two weeks after the sixth ketamine infusion, which was independent of the reductions in depressive symptoms (all p’s < 0.05).

Conclusion

Anhedonia as measured by the MADRS appeared to not be positively related to suicidal ideation after serial ketamine infusions.

KEY POINTS

• Serial ketamine (0.5 mg/kg) infusions have shown quick and dramatic antisuicidal and antianhedonic effects in patients with depression.

• The association between anhedonia and suicidal ideation after serial ketamine infusions is unclear.

• Anhedonia appeared to not be positively related to suicidal ideation after serial ketamine infusions.

Keywords:

• Ketamine
• Montgomery–Åsberg Depression Rating Scale
• anhedonia
• suicidal ideation
• depression
• clinical trial

Acknowledgment

The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was funded by the National Natural Science Foundation of China [82101609], Scientific Research Project of Guangzhou Bureau of Education [202032762], Science and Technology Program Project of Guangzhou [202102020658], Science and Technology Planning Project of Liwan District of Guangzhou [202004034], Guangzhou Health Science and Technology Project [20211A011045], Guangzhou Science and Technology Project of Traditional Chinese Medicine and Integrated Traditional Chinese and Western Medicine [20212A011018], China International Medical Exchange Foundation [Z-2018-35-2002], Guangzhou Clinical Characteristic Technology Project [2019TS67], and Science and Technology Program Project of Guangzhou [202102020658].