MIR

Study design

Randomised Controlled Trial: To test whether the addition of the antidepressant Mirtazapine is effective in reducing the symptoms of depression compared with placebo in patients who have been treated with a Serotonin Selective Reuptake Inhibitor (SSRI) or Serotonin and Noradrenaline Reuptake Inhibitor (SNRI) for at least six weeks.

Primary objective

To investigate in adults≥18 years in primary care with treatment resistant depression (TRD) if the use of mirtazapine, compared with placebo, reduces the symptoms of depression measured as a continuous variable at 12 weeks using the Beck Depression Inventory (BDI). We will also describe a binary variable using the BDI, representing response, defined as a reduction in depressive symptoms of at least 50% compared to baseline, a widely used definition of improvement 
Secondary objectives: In relation to the use of mirtazapine compared with placebo we will also
1. Describe the rate of remission of symptoms, defined as a score on the BDI of less than 10 
2. Describe any change on a measure of generalized anxiety, the Generalised Anxiety Disorder & Questionnaire (GAD-7) 
3. All of the above outcomes measured at 24 weeks and 12 months 
4. Measure antidepressant use and adherence 
5. Estimate the cost-effectiveness from the perspectives of the NHS, patients, and society 
6. Compare all adverse events including: any new symptoms or worsening of existing symptoms, re-consultations for a documented deterioration in illness and Serious Adverse Events

Interventions

Mirtazapine