Introduction:
Depression, particularly medication-resistant depression, remains a global challenge, and esketamine, an innovative treatment targeting the glutamatergic system, offers a promising alternative for patients who do not respond to traditional antidepressants.

Aim:
The study aimed to evaluate the therapeutic potential of esketamine, especially for patients who did not respond to standard antidepressant therapy.

Material and methods:
The sample consisted of 30 patients diagnosed with medication-resistant depression, who were divided into 3 groups of 10 people each, based on blood pressure fluctuations during treatment. The study was conducted in Warsaw and Bytom (Poland), from July 9, 2024 to September 12, 2024 inclusive.

Results and discussion:
The Montgomery-Asberg Depression Rating Scale was used to assess therapy effectiveness, with blood pressure monitored for cardiovascular reactions. Depression levels decreased over time. The 2nd group, starting with severe depression, showed the greatest improvement, reducing depression by 29 points, reaching a mild form. The 1st and 3rd groups reduced their depression by 16 and 18 points, respectively, reaching remission. During the supportive phase, all groups remained stable with minor fluctuations.

Conclusions:
Esketamine showed a rapid and effective impact on reducing depressive symptoms. Blood pressure changes varied: the 1st group had stable levels, the 2nd showed fluctuations, and the 3rd experienced sharp increases and decreases, indicating individual responses to side effects. These findings highlight esketamine’s effectiveness in treating severe depression but emphasize the need for medical supervision due to blood pressure fluctuations.