We conducted a 12-week, double-blind, randomized, placebo-controlled trial to assess the effectiveness of EPA or SPM treatments versus a placebo in managing Long COVID symptoms in adult patients. We planned to enroll 240 eligible participants from various general and psychiatric hospitals in Taiwan. The focus was on evaluating the therapeutic impact and potential side effects of administering 3 g/day of EPA or 1.67 mg/day of SPMs on symptoms of depression in these patients. This consolidated approach aims to provide comprehensive insights into the efficacy of EPA and SPM treatments in Long COVID cases, addressing crucial mental health aspects.

Inclusion Criteria:

• (1) confirmed SARS-CoV-2 infection by PCR, documented positive test, or clinician diagnosis; (2) meeting CDC criteria for Post-COVID Conditions (Long COVID) as the presence of new, returning, or ongoing symptoms ≥4 weeks after confirmed SARS-CoV-2 infection; (3) Hamilton Depression Rating Scale (HAMD-21) score ≥18 at baseline; (4) stable antidepressant treatment for ≥4 weeks or no current antidepressant use; and (5) ability to provide written informed consent

Exclusion Criteria:

• (1) current or past six-month diagnosis of psychotic disorder, bipolar disorder, substance use disorder, or other major psychiatric conditions based on ICD-10 or DSM-5 criteria; (2) significant neurological or medical comorbidities (eg, epilepsy, traumatic brain injury, autoimmune disease, cancer), acute infections, or clinically significant laboratory abnormalities; (3) regular use of SPM or EPA supplementation >0·5 g/day; (4) known allergy or intolerance to omega-3 fatty acids or SPMs; and (5) requirement for inpatient psychiatric care due to acute suicide risk