N-Acetyl Cysteine Supplementation in Therapy Refractory Major Depressive Disorders

The aim of this study is to evaluate the efficacy of N-acetylcysteine (NAC) add-on to antidepressant medication in treating patients who do not relieve during standard antidepressant treatment for 6 weeks at least. Meanwhile, secondary outcomes will include changes in some biomarkers and on specifically local brain activity (functional Magnetic Resonance Imaging, fMRI) and white matter integrity (Diffusion Tensor Imaging, DTI). The hypothesis of this study is that NAC has positive effects on refractory major depressive disorder patients with increased inflammatory activity.

It's a double-blind randomised placebo controlled antidepressant augmentation study with 12-week treatment and 8-week follow up. Its purpose is to investigate antidepressant efficacy and safety of NAC in patients with treatment resistant depression (TRD) defined as insufficient response to 1 or more antidepressants given for at least 6 weeks and in an adequate dose, displaying increased peripheral inflammatory activity and moderate to severe depression. Apart from studying the effects of NAC on depression severity, the secondary outcomes are to examine a range of biomarkers related to potentially important underlying mechanisms such as oxidative stress and inflammatory activity and to evaluate the effects on brain functioning (fMRI) and on white matter integrity (DTI). Scale assessments are performed in the week preceding initiation of treatment, during the treatment period, at the end of the treatment period and at 8-week follow up. Neuro-imaging is performed before the treatment starts and in week 12, before the study medication is terminated. Collection of blood and morning urine only takes place at three time points, in the week preceding initiation of treatment, closely before tapering off the study medication and at the end of 8-week follow up. This study is hoped to show that NAC perform positive effects on those aspects mentioned above.