A randomized, double-blind, placebo-controlled trial was conducted to assess the effect of magnesium glycinate on symptoms of moderate to severe depression in 90 patients. Patients were assessed at baseline, end of the 4 weeks, and end of the 8 weeks of treatment. Patients were randomized to receive either 200 mg elemental magnesium or 200 mg placebo tablet twice daily for 8 weeks. The primary outcome measure was depression severity score assessment using Depression Anxiety Stress Scale 21 items Bangla Version (DASS-21 BV) and the secondary outcome measure was serum magnesium level estimation and side effects assessment using a preformed checklist.

Major depressive disorder (MDD), is a mood disorder affecting 300 million people worldwide with a prevalence of 6.7% in Bangladesh. Depression is the main contributor to suicidal deaths and is globally ranked as the single largest contributor to non-fatal health loss. Various psychological, genetic, environmental, and biochemical factors are presumed to be involved in the causation of MDD. About 30% to 50% of patients do not respond to initial antidepressant medication, and 15% of them continue to suffer from symptoms despite the completion of multiple antidepressants and more aggressive treatment regimens, in addition to facing untoward adverse drug reactions with increasing dose. Recent trials attempted to assess the effect of magnesium in reducing depressive symptoms in MDD patients. This study evaluates whether there was any role of magnesium in reducing depressive symptoms between those who did and did not receive magnesium in 8 weeks period. Patients attending the Outpatient Department of Psychiatry, BSMMU, and diagnosed with MDD were evaluated using the DASS-21 BV for assessment of severity. Those patients who were experiencing moderate to severe symptoms (scores of 14-27) were enrolled according to inclusion and exclusion criteria. Total enrolled 90 MDD patients who have received either 200 mg elemental magnesium twice daily in the form of magnesium glycinate tablet or 200 mg placebo tablet twice daily for 8 weeks. A baseline depression severity score assessment was done using DASS-21 items and again repeated at the end of the 4 weeks and 8 weeks of treatment. Initially, baseline serum magnesium level (mg/dL) was measured and repeated again at the end of the 8 weeks of treatment. DASS-21 is a validated set of three self-report scales to measure the state of depression, anxiety, and stress, where each of the three scales contains 7 items, and each item is rated from 0 to 3. The depression scale assesses dysphoria, hopelessness, devaluation of life, self-deprecation, lack of interest, anhedonia, and inertia.

Inclusion Criteria:

• Newly diagnosed 18 years or older MDD patients of both gender according to DSM-5 at the Outpatient Department of Psychiatry, BSMMU
• Moderate to severe MDD according to DASS-21 (scores of 14-27)
• Patients prescribed only SSRIs

Exclusion Criteria:

• Patients having any other psychiatric disease, kidney disease, or gastrointestinal disease
• Taking dietary supplements in the last two months
• Taking fluoroquinolones, aminoglycosides, tetracyclines, calcium channel blockers, bisphosphonates, and skeletal muscle relaxants
• Pregnancy and lactation

A clinical trial design strategy in which one or more parties involved in the trial, such as the investigator or participants, do not know which participants have been assigned which interventions. The type of masking was double-blind masking.