Effect of ketamine on anxiety: findings from the Ketamine for Adult Depression Study.
The British journal of psychiatry : the journal of mental science – January 07, 2025
Source: PubMed
Summary
Groundbreaking clinical trial reveals ketamine's dual benefit in treating both anxiety and depression. In this controlled study, patients receiving flexible-dose ketamine showed significant anxiety reduction compared to those given a control medication. The twice-weekly treatments over 4 weeks proved most effective when doctors could adjust dosing to each patient's needs. Results showed meaningful improvements in mental health symptoms, particularly when higher doses were used, highlighting ketamine's potential as a powerful tool for treating complex mood disorders.
Abstract
Anxiety disorders and treatment-resistant major depressive disorder (TRD) are often comorbid. Studies suggest ketamine has anxiolytic and antidepressant properties. To investigate if subcutaneous racemic ketamine, delivered twice weekly for 4 weeks, reduces anxiety in people with TRD. The Ketamine for Adult Depression Study was a multisite 4-week randomised, double-blind, active (midazolam)-controlled trial. The study initially used fixed low dose ketamine (0.5 mg/kg, cohort 1), before protocol revision to flexible, response-guided dosing (0.5-0.9 mg/kg, cohort 2). This secondary analysis assessed anxiety using the Hamilton Anxiety (HAM-A) scale (primary measure) and 'inner tension' item 3 of the Montgomery-Åsberg Depression Rating Scale (MADRS), at baseline, 4 weeks (end treatment) and 4 weeks after treatment end. Analyses of change in anxiety between ketamine and midazolam groups included all participants who received at least one treatment (n = 174), with a mixed effects repeated measures model used to assess the primary anxiety measure. The trial was registered at www.anzctr.org.au (ACTRN12616001096448). In cohort 1 (n = 68) the reduction in HAM-A score was not statistically significant: -1.4 (95% CI [-8.6, 3.2], P = 0.37), whereas a significant reduction was seen for cohort 2 (n = 106) of -4.0 (95% CI [-10.6, -1.9], P = 0.0058), favouring ketamine over midazolam. These effects were mediated by total MADRS and were not maintained at 4 weeks after treatment end. MADRS item 3 was also significantly reduced in cohort 2 (P = 0.026) but not cohort 1 (P = 0.96). Ketamine reduces anxiety in people with TRD when administered subcutaneously in adequate doses.