Treating Immuno-metabolic Depression With Anti-inflammatory Drugs

Interventional Allocation: Randomized. Intervention model: Parallel Assignment. Primary purpose: Treatment. Masking: Quadruple (Participant, Care Provider, Investigator, Outcomes Assessor). Phase 3 Inclusion Criteria: - DSM-5 diagnosis of MDD confirmed with clinical interview (MINI-S voor DSM-5 Nederlandse versie 2019) - Currently using an SSRI or SNRI, subjects should be on the current medication for at least 4 weeks - IDS-SR score =26 (moderate to severe depressive symptoms) and a score =6 on atypical, energy-related symptoms scale from IDS - CRP > 1mg/L - A female participant is eligible to participate if she is not pregnant or breastfeeding, and one of the following conditions applies: 1) is not a woman of child bearing potential (WOCBP); 2) Is a WOCBP and agrees to use, or is already using, a contraceptive method during the intervention period and up to 1 month after the intervention - Signed informed consent Exclusion Criteria: - Contraindications for celecoxib (history of: peptic ulcers, gastrointestinal bleeding, ischemic heart disease, stroke, heart failure, allergic reactions to aspirin/NSAIDs/coxibs; impaired kidney function (creatinine clearance < 30 ml/min), impaired liver function (ALT > 2x ULT) - ECT in the past 3 months - Being on antidepressants other than SSRIs or SNRIs or being on other psychotropic drugs - Starting other evidence-based non-pharmacological intervention for depression (e.g. psychotherapy) in the 4 weeks before randomization. - Clinically overt alcohol/drug dependence or other primary psychiatric diagnoses (schizophrenia, schizoaffective, OCD, or bipolar disorder) - Chronic use of anti-inflammatory drugs and corticosteroids - Current use of anticoagulants - Not speaking Dutch Depressive Disorder, Major;Inflammation Drug: Celecoxib 400mg;Drug: Placebo Depressive symptoms severity Number of participants achieving Response;Number of participants achieving Remission;Symptom profile: atypical, energy-related depressive symptoms (AES)