Anxiety, depression significantly reduced with intramuscular ketamine treatment

Levels of depression and anxiety significantly improved with intramuscular ketamine treatment and did not regress to baseline during a 7-month maintenance treatment interval, according to a study published in BMC Psychiatry.

“Over the past 2 decades, subanesthetic ketamine has emerged as a psychopharmacotherapy option for major depressive disorder (MDD) due to its rapid antidepressant and antisuicidal effects,” Sachin Ahuja, of Cedar Psychiatry in Utah, and colleagues wrote.

Researchers sought to evaluate the clinical characteristics, treatment patterns, clinical outcomes and adverse events of patients who received IM ketamine treatment.

The retrospective cohort study utilized patient data from electronic health records of a private outpatient psychiatric clinic network in the United States. Included were 452 patients (51% female, median age 36.4 years) aged 18 years and older with any psychiatric diagnosis who received ketamine treatment only by IM administration from January 2018 to June 2021. Patients self-administered the Patient Health Questionnaire-9 (PHQ-9) as well as the Generalized Anxiety Disorder-7 (GAD-7) survey prior to each ketamine administration. The primary outcomes from the study were changes in the median PHQ-9 and GAD-7 scores between each individual’s first and last ketamine treatment. Multiple statistical analyses were employed to assess change in questionnaire scores, association between ketamine dose and patient weight, as well as associations between number of treatments and their respective scores on the PHQ-9 and GAD-7.

Results showed that 420 patients had a diagnosis of major depressive disorder, 243 patients had a diagnosis of generalized anxiety disorder, and 126 patients had a diagnosis of post-traumatic stress disorder.

Patients received a median of four (range 1–48) IM ketamine treatments. Median depression scores (PHQ-9) improved 38% from 16.0 (IQR 11.3–21.8) at baseline to 10.0 (interquartile range 6.0–15.0) at last treatment, while median anxiety scores (GAD-7) improved 50% from 14.0 (IQR 8.0–17.0) at baseline to 7.0 (IQR 4.3–11.8) at last treatment. With maintenance ketamine treatments, average improvements in depression (PHQ-9) and anxiety (GAD-7) scores of at least 4.7 and 4.9 points were maintained for more than 7months. Adverse events occurred during 59 of 2,532 treatments.

“Prospective studies are required to confirm the long-term safety and effectiveness of psychiatric IM ketamine treatment,” Ahuja and colleagues wrote.