[The Impact of Antidepressants on COVID-19 and Post-Acute COVID-19 Syndrome: A Scoping-Review Update].

Introduction Preclinically, fluvoxamine and other antidepressants (AD) exerted antiviral and anti-inflammatory properties also against SARS-COV-2. Therfore, It makes sense to test the clinical effect of AD against COVID-19 and Long COVID.

Methods: On May 20, 2024, this systematic scoping review in PUBMED identified 1016 articles related to AD and COVID-19, Long COVID and SARS-COV-2. These included 10 retrospective "large scale" studies (> 20000 chart reviews), 8 prospective clinical trials (plus 4 regarding Long COVID), 11 placebo-controlled randomized (RCT) (plus 2 regarding Long COVID) and 15 meta-analyses.

Results: COVID-19: Retrospective studies with cohorts taking AD primarily for psychiatric comorbidities or chronic pain conditions directly prior to SARS-COV-2 infection described that this substance class (most studied: Selective Serotonin Re-Uptake Inhibitors (SSRI) and Selective Serotonin Noradrenaline Re-Uptake Inhibitors (SSNRI)) were associated with (i) significantly fewer SARS-COV-2 infections and (ii) a milder course of COVID-19 ("COVID-19 protection"). Ten of the 11 RCTs found regarding COVID-19 tested fluvoxamine, as this old AD appeared suitable as a prophylactic agent against severe COVID-19, taking into account its in vitro potency against the progression of intracellular sepsis cascades. Therefore, most (12 out of 15) meta-analyses also referred to fluvoxamine. They found (iii) a significant (40-70% reduction) in mortality, intubation and hospitalization rates when fluvoxamine was used as an add-on to standard therapy for mild to moderate COVID-19. When this AD was used in the early stages of the disease, it was more successful than when it was given later in advanced, severe COVID-19 (e.g. severe pneumonia, final sepsis stages). A dose dependency was observed: 2x50 mg fluvoxamine over 15 days was less effective than 2x100 or even 3x100 mg with an adverse event profile still at the placebo level. Direct comparisons with drugs approved for COVID-19 do not yet exist. A first indirect meta-analytical comparison showed an advantage of paxlovid or molnupiravir versus fluvoxamine against the development of severe COVID-19: risk reduction of 95% (I2 = N/A, but only one study) or 78% (I2=0) versus 5+-5% (I2=48). However, an add-on of fluvoxamine was still significantly more efficacious than symptom-oriented standard therapy alone. Long COVID: A common Long COVID phenotype with dominant anxiety and depression symptoms, which responds to AD, relaxation therapy and/or psychotherapy, has now been identified. Casuistics report positive effects of AD on fatigue, cognitive and autonomic dysfunctions. A first large prospective open-label RCT has just shown significantly more favourable courses, less viral load and less pro-inflammatory cytokines in the treatment of mild to moderate COVID-19 with fluvoxamine versus standard treatment, also with regard to the subsequent development of neuropsychiatric and pulmonary Long COVID or fatigue.

Conclusion: Overall, there is promising evidence of a preventive effect of AD (especially fluvoxamine) against progression to severe COVID-19 and against the development of Long COVID. It is likely, that the entire AD substance class could be effective here. This assumption is based on the results of retrospective large scale studies, but awaits verification by better controlled studies. The potential effectiveness/efficacy (currently low and moderate confidence of the evidence for the entire substance class and specifically fluvoxamine, respectively) of fluvoxamine as an add-on against COVID-19 and possibly also directly against Long COVID could stimulate similar projects in other infectious diseases that also have the potential to pose a lasting threat to the health of those affected. We consider the evidence to date to be sufficient to be able to emphasize a possible positive effect of these substances in the psychoeducation of patients with COVID-19 or Long COVID who are already receiving AD for other conditions - especially also against the symptoms associated with the viral disease or its consequences. In regions where neither vaccines nor antiviral agents currently approved for the prevention or treatment of COVID-19 are available, AD and in particular fluvoxamine would be a cost-effective alternative to protect against a severe course, even if this AD appears to have a smaller effect against COVID-19 than the currently approved antiviral agents, but with presumably better tolerability. A direct comparative clinical trial with approved antiviral agents is still pending and should be positive to further open the door for a guideline-based recommendation of fluvoxamine (or perhaps even AD) for COVID-19 or its aftermath.