Post COVID

Fatigue, cognitive problems, post-exertional malaise (PEM) and postural orthostatic tachycardia syndrome (POTS) are common and debilitating symptoms after COVID-19. The pathophysiology of post-COVID is not well understood and there is no established biomedical treatment. Treatment options for post-COVID are thus much needed. A promising candidate intervention is fluvoxamine, a selective serotonin reuptake inhibitor (SSRI), that may reduce post-COVID symptoms because of its regulatory effect on the (neuro) immune system, the hypothalamic-pituitary-adrenal (HPA) axis and the tryptophan system. The investigators will randomize 160 participants to either fluvoxamine or placebo for 12 weeks. The investigators will use advanced functional neuroimaging techniques during cognitive challenge (optional substudy) and plasma biomarkers (inflammatory markers, cortisol, serotonin, IDO-2 activity), to facilitate identifying potential mechanistic pathways of post -COVID treatment.

The goal of this clinical trial is to examine the efficacy of this manual for mental health in people with mixed neurological disorders, including post-COVID. These conditions are often associated with cognitive impairment, which may hamper the effects of psychoterapy. Executive functioning and especially the ability to abstract thinking may be useful for individuals using Acceptance and Commitment Therapy. Therefore, the main questions research questions are: * Is this intervention effective in improving mental health? * Do executive functions predict the extent of social participation and mental health at the end of therapy? Participants will take part in 8 weekly group therapy sessions of 100 minutes each.