Antianhedonic Effect of Repeated Ketamine Infusions in Patients With Treatment Resistant Depression

In this open-label study (n=42) participants with treatment-resistant depression (TRD) received eight ketamine infusions (0.5 mg/kg) over four weeks while continuing their conventional treatment regimes. Ketamine significantly reduced participants level of anhedonia (inability to feel pleasure) and these effects lasted longer in patients who were not using benzodiazepines.


“Anhedonia constitutes one of the main symptoms of depressive episode. It correlates with suicidality and significantly effects the quality of patient’s lives. Available treatments are not sufficient against this group of symptoms. Ketamine is a novel, rapid acting strategy for treatment resistant depression. Here we report the change in symptoms of anhedonia measured by Snaith-Hamilton Pleasure Scale as an effect of eight ketamine infusions as an add-on treatment in 42 patients with treatment resistant depression. We also determined the effect of this change on the severity of depressive symptoms measured by Inventory for Depression Symptomatology-Self Report 30-Item (IDS-SR 30). We have observed statistically significant decrease in the level of anhedonia during ketamine treatment. After adjusting for potential confounders we have found that significant reduction in Snaith-Hamilton Pleasure Scale (SHAPS) after each infusion and 1 week post treatment was observed only among patients who did not use benzodiazepines. The reduction in symptoms of anhedonia mediates the antidepressive effect of ketamine. The results need replication in a larger randomized placebo controlled trial.”

Authors: Alina Wilkowska, Mariusz Stanislaw Wiglusz, Maria Galusko-Wegielink, Adam Wlodarczyk & Wieslaw J. Cubala

Study details

Compounds studied

Topics studied
Depression Treatment-Resistant Depression

Study characteristics

42 Humans


Authors associated with this publication with profiles on Blossom

Maria Galusko-Wegielink
Maria Gałuszko-Węgielnik is a psychiatrist associated with the Medical University of Gdansk. Her psychedelic work is currently investigating the effect of ketamine on (treatment-resistant) depression.


Institutes associated with this publication

Medical University of Gdansk
The Medical University of Gdańsk is the largest medical academic institution in northern Poland.

Compound Details

The psychedelics given at which dose and how many times

Ketamine 0.5 - 0.5
mg | 8x

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