The novel coronavirus known as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the global spread of Corona Virus Disease 2019 (COVID-19). While our knowledge about the virus continuously grows, it is still rather unclear how and in which ways it can affect the central nervous system (CNS) and the mental state of affected patients. Our review provides insight into the occurrence of mental disorders in COVID-19 patients. We also collected information about the biological basis of the susceptibility of brain cells to SARS-CoV-2 and its implication to psychiatric manifestations. We included 24 publications in our review, reporting psychiatric manifestations published between 31 December 2019 and 30 July 2020, using the Preferred Reporting Items for Systemic Review and Meta-Analysis statement. Mental disorders occurred in up to one-fifth of patients during the acute phase of the infection. The most common disorders included anxiety-related disorders, mood-spectrum disorders, impaired consciousness, confusion, delirium and psychosis. Long-term manifestations were mainly depression and an increased prevalence of post-traumatic stress symptoms. The brain areas which are affected by SARS-COV-2 included mainly the hypothalamus and associated structures. Our reviewed publications substantiate that SARS-COV-2 infiltrates the CNS directly via an olfactory route. The obtained data allow the statement that direct infection of the CNS by SARS-CoV-2 could be responsible for the observed findings. While most of the mental disorders arise during the clinical course, it is crucial to bear in mind that some isolated cases of COVID-19 present initially with psychiatric disorders. To further investigate long-term psychiatric manifestations, randomized controlled studies must be initiated.

Keywords: Mental disorders, Psychiatry, Brain changes, Covid-19, Susceptibility, SARS-CoV-2