Antidepressant Use and Its Association with 28-Day Mortality in Inpatients with SARS-CoV-2: Support for the FIASMA Model against COVID-19

Cholesterol and COVID-19-therapeutic opportunities at the host/virus interface during cell entry

The rapid development of vaccines to combat severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections has been critical to reduce the severity of COVID-19. However, the continuous emergence of new SARS-CoV-2 subtypes highlights the need to develop additional approaches that oppose viral infections. Targeting host factors that support virus entry, replication, and propagation provide opportunities to lower SARS-CoV-2 infection rates and improve COVID-19 outcome. This includes cellular cholesterol, which is critical for viral spike proteins to capture the host machinery for SARS-CoV-2 cell entry. Once endocytosed, exit of SARS-CoV-2 from the late endosomal/lysosomal compartment occurs in a cholesterol-sensitive manner. In addition, effective release of new viral particles also requires cholesterol. Hence, cholesterol-lowering statins, proprotein convertase subtilisin/kexin type 9 antibodies, and ezetimibe have revealed potential to protect against COVID-19. In addition, pharmacological inhibition of cholesterol exiting late endosomes/lysosomes identified drug candidates, including antifungals, to block SARS-CoV-2 infection. This review describes the multiple roles of cholesterol at the cell surface and endolysosomes for SARS-CoV-2 entry and the potential of drugs targeting cholesterol homeostasis to reduce SARS-CoV-2 infectivity and COVID-19 disease severity.

AH, Storer RJ, Ounjai P, Kanthawee P, Ngamwongsatit N, Kupwiwat R, Kupwiwat C, Brimson JM, Devanga Ragupathi NK, Charuluxananan S, Leelahavanichkul A, Kanjanabuch T, Higgins PG, Badavath VN, Amarasiri M, Verhasselt V, Kicic A, Chatsuwan T, Pirzada K, Jalali F, Reiersen AM, Abe S, Ishikawa H. Early treatment with fluvoxamine, bromhexine, cyproheptadine, and niclosamide to prevent clinical deterioration in patients with symptomatic COVID-19: a randomized clinical trial

Background

Repurposed drugs with host-directed antiviral and immunomodulatory properties have shown promise in the treatment of COVID-19, but few trials have studied combinations of these agents. The aim of this trial was to assess the effectiveness of affordable, widely available, repurposed drugs used in combination for treatment of COVID-19, which may be particularly relevant to low-resource countries.

Methods

We conducted an open-label, randomized, outpatient, controlled trial in Thailand from October 1, 2021, to June 21, 2022, to assess whether early treatment within 48-h of symptoms onset with combinations of fluvoxamine, bromhexine, cyproheptadine, and niclosamide, given to adults with confirmed mild SARS-CoV-2 infection, can prevent 28-day clinical deterioration compared to standard care. Participants were randomly assigned to receive treatment with fluvoxamine alone, fluvoxamine + bromhexine, fluvoxamine + cyproheptadine, niclosamide + bromhexine, or standard care. The primary outcome measured was clinical deterioration within 9, 14, or 28 days using a 6-point ordinal scale. This trial is registered with ClinicalTrials.gov (NCT05087381).

Findings

Among 1900 recruited, a total of 995 participants completed the trial. No participants had clinical deterioration by day 9, 14, or 28 days among those treated with fluvoxamine plus bromhexine (0%), fluvoxamine plus cyproheptadine (0%), or niclosamide plus bromhexine (0%). Nine participants (5.6%) in the fluvoxamine arm had clinical deterioration by day 28, requiring low-flow oxygen. In contrast, most standard care arm participants had clinical deterioration by 9, 14, and 28 days. By day 9, 32.7% (110) of patients in the standard care arm had been hospitalized without requiring supplemental oxygen but needing ongoing medical care. By day 28, this percentage increased to 37.5% (21). Additionally, 20.8% (70) of patients in the standard care arm required low-flow oxygen by day 9, and 12.5% (16) needed non-invasive or mechanical ventilation by day 28. All treated groups significantly differed from the standard care group by days 9, 14, and 28 (p < 0.0001). Also, by day 28, the three 2-drug treatments were significantly better than the fluvoxamine arm (p < 0.0001). No deaths occurred in any study group. Compared to standard care, participants treated with the combination agents had significantly decreased viral loads as early as day 3 of treatment (p < 0.0001), decreased levels of serum cytokines interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), and interleukin-1 beta (IL-1β) as early as day 5 of treatment, and interleukin-8 (IL-8) by day 7 of treatment (p < 0.0001) and lower incidence of post-acute sequelae of COVID-19 (PASC) symptoms (p < 0.0001). 23 serious adverse events occurred in the standard care arm, while only 1 serious adverse event was reported in the fluvoxamine arm, and zero serious adverse events occurred in the other arms.

Interpretation

Early treatment with these combinations among outpatients diagnosed with COVID-19 was associated with lower likelihood of clinical deterioration, and with significant and rapid reduction in the viral load and serum cytokines, and with lower burden of PASC symptoms. When started very soon after symptom onset, these repurposed drugs have high potential to prevent clinical deterioration and death in vaccinated and unvaccinated COVID-19 patients.

Funding

Ped Thai Su Phai (Thai Ducks Fighting Danger) social giver group.

Excess mortality and its causes among older adults with schizophrenia versus those with bipolar disorder and major depressive disorder: a 5-year prospective multicenter study

Excess mortality observed in people with schizophrenia may persist in later life. The specific causes of increased mortality observed in older adults with schizophrenia and the potential influence of psychotropic medications remain partly unknown. We compared 5-year mortality and its causes of older adults with schizophrenia to bipolar disorder (BD) or major depressive disorder (MDD). We used a 5-year prospective cohort, including 564 older inpatients and outpatients with schizophrenia, BD or MDD (mean age: 67.9 years, SD = 7.2 years). Causes of death were cardiovascular disorder (CVD) mortality, non-CVD disease-related mortality (e.g., infections), suicide, and unintentional injury. The primary analysis was a multivariable logistic model with inverse probability weighting (IPW) to reduce the effects of confounders, including sociodemographic factors, duration and severity of the disorder, and psychiatric and non-psychiatric comorbidity. Five-year all-cause mortality among older participants with schizophrenia and with BD or MDD were 29.4% (n = 89) and 18.4% (n = 45), respectively. Following adjustments, schizophrenia compared to MDD or BD was significantly associated with increased all-cause mortality (AOR = 1.35; 95%CI = 1.04-1.76; p = 0.024) and cardiovascular mortality (AOR = 1.50; 95%CI = 1.13-1.99; p = 0.005). These associations were significantly reduced among patients taking antidepressants [interaction odds ratio (IOR) = 0.42; 95%CI = 0.22-0.79; p = 0.008 and IOR = 0.39: 95%CI = 0.16-0.94; p = 0.035, respectively]. Schizophrenia was associated with higher mortality compared to BD or MDD. Cardiovascular diseases explained most of this excess mortality. Exploratory analyses suggested that psychotropic medications did not influence this excess mortality, except for antidepressants, which were associated with significantly reduced between-group difference in all-cause and cardiovascular mortality.

Association of fluvoxamine with mortality and symptom resolution among inpatients with COVID-19 in Uganda: a prospective interventional open-label cohort study

Prior research suggests that fluvoxamine, a selective serotonin reuptake inhibitor (SSRI) used for the treatment of obsessive-compulsive disorder and major depressive disorder, could be repurposed against COVID-19. We undertook a prospective interventional open-label cohort study to evaluate the efficacy and tolerability of fluvoxamine among inpatients with laboratory-confirmed COVID-19 in Uganda. The main outcome was all-cause mortality. Secondary outcomes were hospital discharge and complete symptom resolution. We included 316 patients, of whom 94 received fluvoxamine in addition to standard care [median age, 60 years (IQR = 37.0); women, 52.2%]. Fluvoxamine use was significantly associated with reduced mortality [AHR = 0.32; 95% CI = 0.19-0.53; p < 0.001, NNT = 4.46] and with increased complete symptom resolution [AOR = 2.56; 95% CI = 1.53-5.51; p < 0.001, NNT = 4.44]. Sensitivity analyses yielded similar results. These effects did not significantly differ by clinical characteristic, including vaccination status. Among the 161 survivors, fluvoxamine was not significantly associated with time to hospital discharge [AHR 0.81, 95% CI (0.54-1.23), p = 0.32]. There was a trend toward greater side effects with fluvoxamine (7.45% versus 3.15%; SMD = 0.21; χ2 = 3.46, p = 0.06), most of which were light or mild in severity and none of which were serious. One hundred mg of fluvoxamine prescribed twice daily for 10 days was well tolerated and significantly associated with reduced mortality and with increased complete symptom resolution, without a significant increase in time to hospital discharge, among inpatients with COVID-19. Large-scale randomized trials are urgently needed to confirm these findings, especially for low- and middle-income countries, where access to vaccines and approved treatments against COVID-19 is limited.

Antipsychotic use and 28-day mortality in patients hospitalized with COVID-19: A multicenter observational retrospective study

Prior research has yielded conflicting results about the potential influence of antipsychotics in patients with COVID-19. In this multicenter retrospective study, we examined the association of antipsychotic use at admission with 28-day all-cause mortality in a sample of 59,021 adult patients hospitalized with COVID-19 from January 2020 to November 2021. In a 1:1 ratio matched analytic sample (N=1,454) accounting for age, sex, hospital, hospitalization period, the Elixhauser Comorbidity Index, other psychotropic medications, medications prescribed according to compassionate use or as part of a clinical trial, current diagnoses of psychiatric disorders, and clinical and biological markers of COVID-19 severity, antipsychotic use was not associated with 28-day mortality [23.5% (N=727) versus 18.6% (N=727); OR=1.16; 95%CI=0.89-1.51; p=0.280]. This association remained non-significant in exploratory analyses across all classes of antipsychotics and individual molecules, except for typical antipsychotics and loxapine, which were significantly linked to increased 28-day mortality, associations likely due to residual indication bias. Contrariwise, antipsychotics prescribed at daily doses higher than 200 mg of chlorpromazine-equivalents might be associated with reduced 28-day mortality when compared to patients not taking antipsychotics in the matched analytic sample [10.4% (N=154) versus 18.6% (N=727); AOR=0.56; 95%CI=0.31-0.96; p=0.040]. These results suggest that antipsychotic use, when prescribed at usual doses, are not be associated with 28-day mortality in patients hospitalized with COVID-19.

Impact of lithium on mortality among older adults with major psychiatric disorders: A 5-year prospective multicenter study

OBJECTIVE

Prior studies report conflicting results about the association between lithium use and all-cause mortality. In addition, data are scarce on this association among older adults with psychiatric disorders. In this report, we sought to examine the associations of lithium use with all-cause mortality and specific causes of death (i.e., due to cardiovascular disorder, non-cardiovascular disease, accident, or suicide) among older adults with psychiatric disorders during a 5-year follow-up period.

METHODS

In this observational epidemiological study, we used data from 561 patients belonging to a Cohort of individuals with Schizophrenia or Affective disorders aged 55-years or more (CSA). Patients taking lithium at baseline were first compared to patients not taking lithium, and then to patients taking (i) antiepileptics and (ii) atypical antipsychotics in sensitivity analyses. Analyses were adjusted for socio-demographic (e.g., age, gender), clinical characteristics (e.g., psychiatric diagnosis, cognitive functioning), and other psychotropic medications (e.g. benzodiazepines).

RESULTS

There was no significant association between lithium use and all-cause mortality [AOR=1.12; 95%CI=0.45-2.79; p=0.810] or disease-related mortality [AOR=1.37; 95%CI=0.51-3.65; p=0.530]. None of the 44 patients taking lithium died from suicide, whereas 4.0% (N=16) of patients not receiving lithium did.

CONCLUSION

These findings suggest that lithium may not be associated with all-cause or disease-related mortality and might be associated with reduced risk of suicide in this population. They argue against the underuse of lithium as compared with antiepileptics and atypical antipsychotics among older adults with mood disorders.

Drug-induced phospholipidosis is not correlated with the inhibition of SARS-CoV-2 - inhibition of SARS-CoV-2 is cell line-specific

Recently, Tummino et al. reported that 34 compounds, including Chloroquine and Fluoxetine, inhibit SARS-CoV-2 replication by inducing phospholipidosis, although Chloroquine failed to suppress viral replication in Calu-3 cells and patients. In contrast, Fluoxetine represses viral replication in human precision-cut lung slices (PCLS) and Calu-3 cells. Thus, it is unlikely that these compounds have similar mechanisms of action. Here, we analysed a subset of these compounds in the viral replication and phospholipidosis assays using the Calu-3 cells and PCLS as the patient-near system. Trimipramine and Chloroquine induced phospholipidosis but failed to inhibit SARS-CoV-2 replication in Calu-3 cells, which contradicts the reported findings and the proposed mechanism. Fluoxetine, only slightly induced phospholipidosis in Calu-3 cells but reduced viral replication by 2.7 orders of magnitude. Tilorone suppressed viral replication by 1.9 orders of magnitude in Calu-3 cells without causing phospholipidosis. Thus, induction of phospholipidosis is not correlated with the inhibition of SARS-CoV-2, and the compounds act via other mechanisms. However, we show that compounds, such as Amiodarone, Tamoxifen and Tilorone, with antiviral activity on Calu-3 cells, also inhibited viral replication in human PCLS. Our results indicate that antiviral assays against SARS-CoV-2 are cell-line specific. Data from Vero E6 can lead to non-transferable results, underlining the importance of an appropriate cell system for analysing antiviral compounds against SARS-CoV-2. We observed a correlation between the active compounds in Calu-3 cells and PCLS.

Medications Modulating the Acid Sphingomyelinase/Ceramide System and 28-Day Mortality among Patients with SARS-CoV-2: An Observational Study

Prior evidence indicates the potential central role of the acid sphingomyelinase (ASM)/ceramide system in the infection of cells with SARS-CoV-2. We conducted a multicenter retrospective observational study including 72,105 adult patients with laboratory-confirmed SARS-CoV-2 infection who were admitted to 36 AP-HP (Assistance Publique-Hôpitaux de Paris) hospitals from 2 May 2020 to 31 August 2022. We examined the association between the ongoing use of medications functionally inhibiting acid sphingomyelinase (FIASMA), which reduces the infection of cells with SARS-CoV-2 in vitro, upon hospital admission with 28-day all-cause mortality in a 1:1 ratio matched analytic sample based on clinical characteristics, disease severity and other medications (N = 9714). The univariate Cox regression model of the matched analytic sample showed that FIASMA medication use at admission was associated with significantly lower risks of 28-day mortality (HR = 0.80; 95% CI = 0.72-0.88; p < 0.001). In this multicenter observational study, the use of FIASMA medications was significantly and substantially associated with reduced 28-day mortality among adult patients hospitalized with COVID-19. These findings support the continuation of these medications during the treatment of SARS-CoV-2 infections. Randomized clinical trials (RCTs) are needed to confirm these results, starting with the molecules with the greatest effect size in the study, e.g., fluoxetine, escitalopram, and amlodipine.

COVID-19 mortality among selective serotonin reuptake inhibitor users-results from a nationwide cohort

OBJECTIVE

To examine differences in mortality and/or severe acute respiratory syndrome between selective serotonin reuptake inhibitor- (SSRI) users and non-SSRI users up to 60 days after a positive SARS-CoV-2 real-time reverse transcription PCR test.

METHODS

Retrospective cohort study including all Danish residents above the age of eighteen with a positive SARS-CoV-2 PCR test from 26 February, 2020 to 5 October, 2021. The follow-up period was 60 days. The primary outcome was all-cause mortality, and the secondary outcome was severe acute respiratory syndrome. Exposure of interest was SSRI use. Differences between SSRI users and non-users were examined with Cox regression.

RESULTS

Altogether, 286,447 SARS-CoV-2 positive individuals were identified, and 7113 met the criteria for SSRI use. SSRI users had a mean age of 50.4 years, and 34% were males. Non-SSRI users had a mean age of 41.4 years, and 50% were males. Similar vaccination frequency was observed among the two groups. Sertraline was the most commonly used SSRI, followed by citalopram and escitalopram. We found 255 deaths among SSRI users (3.6%) and 2872 deaths among non-SSRI users (1.0%). SSRI use was significantly associated with increased mortality, with a hazard ratio of 1.32 (95% confidence interval, 1.16 -1.50; p 0.015), even when adjusting for age, sex, vaccination status, and comorbidities.

DISCUSSION

We found significantly higher mortality when comparing SSRI users to non-SSRI users within 60 days after a positive SARS-CoV-2 PCR test. Even when considering possible residual confounding, a positive effect of SSRI intake seems highly unlikely. Our study therefore speaks against the hypothesis of repurposing SSRI drugs for COVID-19 treatment.

Antidepressant drug prescription and incidence of COVID-19 in mental health outpatients: a retrospective cohort study

BACKGROUND

Currently, the main pharmaceutical intervention for COVID-19 is vaccination. While antidepressant (AD) drugs have shown some efficacy in treatment of symptomatic COVID-19, their preventative potential remains largely unexplored. Analysis of association between prescription of ADs and COVID-19 incidence in the population would be beneficial for assessing the utility of ADs in COVID-19 prevention.

METHODS

Retrospective study of association between AD prescription and COVID-19 diagnosis was performed in a cohort of community-dwelling adult mental health outpatients during the 1st wave of COVID-19 pandemic in the UK. Clinical record interactive search (CRIS) was performed for mentions of ADs within 3 months preceding admission to inpatient care of the South London and Maudsley (SLaM) NHS Foundation Trust. Incidence of positive COVID-19 tests upon admission and during inpatient treatment was the primary outcome measure.

RESULTS

AD mention was associated with approximately 40% lower incidence of positive COVID-19 test results when adjusted for socioeconomic parameters and physical health. This association was also observed for prescription of ADs of the selective serotonin reuptake inhibitor (SSRI) class.

CONCLUSIONS

This preliminary study suggests that ADs, and SSRIs in particular, may be of benefit for preventing COVID-19 infection spread in the community. The key limitations of the study are its retrospective nature and the focus on a mental health patient cohort. A more definitive assessment of AD and SSRI preventative potential warrants prospective studies in the wider demographic.

Comorbidity Patterns and Mortality Among Hospitalized Patients with Psychiatric Disorders and COVID-19

OBJECTIVE

To examine the association between psychiatric and non-psychiatric comorbidity and 28-day mortality among patients with psychiatric disorders and COVID-19.

METHODS

We performed a multicenter observational retrospective cohort study of adult patients with psychiatric disorders hospitalized with laboratory-confirmed COVID-19 at 36 Greater Paris University hospitals (January 2020-May 2021) (N=3,768). First, we searched for different subgroups of patients according to their psychiatric and non-psychiatric comorbidities through cluster analysis. Next, we compared 28-day all-cause mortality rates across the identified clusters, while taking into account sex, age, and the number of medical conditions.

RESULTS

We found 5 clusters of patients with distinct psychiatric and non-psychiatric comorbidity patterns. Twenty-eight-day mortality in the cluster of patients with mood disorders was significantly lower than in other clusters. There were no significant differences in mortality across other clusters.

CONCLUSIONS

All psychiatric and non-psychiatric conditions may be associated with increased mortality in patients with psychiatric disorders and COVID-19. The lower risk of death among patients with mood disorders might be in line with the potential beneficial effect of certain antidepressants in COVID-19, but requires further research. These findings help identify at-risk patients with psychiatric disorders who should benefit from vaccine booster prioritization and other prevention measures.

Repurposing selective serotonin reuptake inhibitors for severity of COVID-19: a population-based study

The World Health Organization has proposed that a search be made for alternatives to vaccines for the prevention and treatment of COVID-19, with one such alternative being selective serotonin reuptake inhibitors (SSRIs). This study thus sought to assess: the impact of previous treatment with SSRI antidepressants on the severity of COVID-19 (risk of hospitalisation, admission to an intensive care unit [ICU], and mortality), its influence on susceptibility to SARS-CoV-2 and progression to severe COVID-19. We conducted a population-based multiple case-control study in a region in the north-west of Spain. Data were sourced from electronic health records. Adjusted odds ratios (aORs) and 95%CIs were calculated using multilevel logistic regression. We collected data from a total of 86 602 subjects: 3060 cases PCR+, 26 757 non-hospitalised cases PCR+ and 56 785 controls (without PCR+). Citalopram displayed a statistically significant decrease in the risk of hospitalisation (aOR=0.70; 95% CI 0.49-0.99, p=0.049) and progression to severe COVID-19 (aOR=0.64; 95% CI 0.43-0.96, p=0.032). Paroxetine was associated with a statistically significant decrease in risk of mortality (aOR=0.34; 95% CI 0.12 – 0.94, p=0.039). No class effect was observed for SSRIs overall, nor was any other effect found for the remaining SSRIs. The results of this large-scale, real-world data study indicate that, citalopram, could be a candidate drug for being repurposed as preventive treatment aimed at reducing COVID-19 patients’ risk of progressing to severe stages of the disease.

Association of severe mental illness and septic shock case fatality rate in patients admitted to the intensive care unit: A national population-based cohort study

BACKGROUND

Patients with severe mental illness (SMI) (i.e., schizophrenia, bipolar disorder, or major depressive disorder) have been reported to have excess mortality rates from infection compared to patients without SMI, but whether SMI is associated with higher or lower case fatality rates (CFRs) among infected patients remains unclear. The primary objective was to compare the 90-day CFR in septic shock patients with and without SMI admitted to the intensive care unit (ICU), after adjusting for social disadvantage and physical health comorbidity.

METHODS AND FINDINGS

We conducted a nationwide, population-based cohort study of all adult patients with septic shock admitted to the ICU in France between January 1, 2014, and December 31, 2018, using the French national hospital database. We matched (within hospitals) in a ratio of 1:up to 4 patients with and without SMI (matched-controls) for age (5 years range), sex, degree of social deprivation, and year of hospitalization. Cox regression models were conducted with adjustment for smoking, alcohol and other substance addiction, overweight or obesity, Charlson comorbidity index, presence of trauma, surgical intervention, Simplified Acute Physiology Score II score, organ failures, source of hospital admission (home, transfer from other hospital ward), and the length of time between hospital admission and ICU admission. The primary outcome was 90-day CFR. Secondary outcomes were 30- and 365-day CFRs, and clinical profiles of patients. A total of 187,587 adult patients with septic shock admitted to the ICU were identified, including 3,812 with schizophrenia, 2,258 with bipolar disorder, and 5,246 with major depressive disorder. Compared to matched controls, the 90-day CFR was significantly lower in patients with schizophrenia (1,052/3,269 = 32.2% versus 5,000/10,894 = 45.5%; adjusted hazard ratio (aHR) = 0.70, 95% confidence interval (CI) 0.65,0.75, p < 0.001), bipolar disorder (632/1,923 = 32.9% versus 2,854/6,303 = 45.3%; aHR = 0.70, 95% CI = 0.63,0.76, p < 0.001), and major depressive disorder (1,834/4,432 = 41.4% versus 6,798/14,452 = 47.1%; aHR = 0.85, 95% CI = 0.81,0.90, p < 0.001). Study limitations include inability to capture deaths occurring outside hospital, lack of data on processes of care, and problems associated with missing data and miscoding in medico-administrative databases.

CONCLUSIONS

Our findings suggest that, after adjusting for social disadvantage and physical health comorbidity, there are improved septic shock outcome in patients with SMI compared to patients without. This finding may be the result of different immunological profiles and exposures to psychotropic medications, which should be further explored.

Antidepressants with anti-inflammatory properties may be useful in long COVID depression

Long COVID, which is characterised by the presence of persistent symptoms following a COVID infection, may also cause long COVID depression (LCD). Although the risk factors for LCD are not directly characterised, prior mental health visits were associated with an increased risk for long COVID, whereas antidepressant use was not. Current evidence suggests that pro-inflammatory factors in the brain are linked to LCD, thus anti-inflammatory agents may be useful in mitigating LCD. Limited evidence suggests that selective serotonin reuptake inhibitors may also be effective in the treatment of LCD.

Causal associations between major depressive disorder and COVID-19

Background

We aimed to evaluate whether major depressive disorder (MDD) could aggravate the outcomes of coronavirus disease 2019 (COVID-19) or whether the genetic liability to COVID-19 could trigger MDD.

Aims

We aimed to assess bidirectional causal associations between MDD and COVID-19.

Methods

We performed genetic correlation and Mendelian randomisation (MR) analyses to assess potential associations between MDD and three COVID-19 outcomes. Literature-based network analysis was conducted to construct molecular pathways connecting MDD and COVID-19.

Results

We found that MDD has positive genetic correlations with COVID-19 outcomes (r_g: 0.10-0.15). Our MR analysis indicated that genetic liability to MDD is associated with increased risks of COVID-19 infection (odds ratio (OR)=1.05, 95% confidence interval (CI): 1.00 to 1.10, p=0.039). However, genetic liability to the three COVID-19 outcomes did not confer any causal effects on MDD. Pathway analysis identified a panel of immunity-related genes that may mediate the links between MDD and COVID-19.

Conclusions

Our study suggests that MDD may increase the susceptibility to COVID-19. Our findings emphasise the need to increase social support and improve mental health intervention networks for people with mood disorders during the pandemic.

Antiviral and Anti-Inflammatory Activities of Fluoxetine in a SARS-CoV-2 Infection Mouse Model

The coronavirus disease 2019 (COVID-19) pandemic continues to cause significant morbidity and mortality worldwide. Since a large portion of the world's population is currently unvaccinated or incompletely vaccinated and has limited access to approved treatments against COVID-19, there is an urgent need to continue research on treatment options, especially those at low cost and which are immediately available to patients, particularly in low- and middle-income countries. Prior in vitro and observational studies have shown that fluoxetine, possibly through its inhibitory effect on the acid sphingomyelinase/ceramide system, could be a promising antiviral and anti-inflammatory treatment against COVID-19. In this report, we evaluated the potential antiviral and anti-inflammatory activities of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and against variants of concern in vitro, i.e., SARS-CoV-2 ancestral strain, Alpha B.1.1.7, Gamma P1, Delta B1.617 and Omicron BA.5. Fluoxetine, administrated after SARS-CoV-2 infection, significantly reduced lung tissue viral titres and expression of several inflammatory markers (i.e., IL-6, TNFα, CCL2 and CXCL10). It also inhibited the replication of all variants of concern in vitro. A modulation of the ceramide system in the lung tissues, as reflected by the increase in the ratio HexCer 16:0/Cer 16:0 in fluoxetine-treated mice, may contribute to explain these effects. Our findings demonstrate the antiviral and anti-inflammatory properties of fluoxetine in a K18-hACE2 mouse model of SARS-CoV-2 infection, and its in vitro antiviral activity against variants of concern, establishing fluoxetine as a very promising candidate for the prevention and treatment of SARS-CoV-2 infection and disease pathogenesis.