Anxious behaviour or depressed mood in COVID-19 patients may be a sign that the virus affects the central nervous system, suggests an international study led by a University of Cincinnati College of Medicine researcher. These two psychological symptoms were most closely associated with a loss of smell and taste rather than the more severe indicators of the novel coronavirus such as shortness of breath, cough or fever, according to the study. Severity of the loss of smell or taste, nasal obstruction, excessive mucus production, fever, cough and shortness of breath during COVID-19 were assessed. The findings of the study are available online in The Laryngoscope. Sedaghat says researchers have long thought that the olfactory tract may be the primary way that coronaviruses enter the central nervous system. There was evidence of this with SARS, or severe acute respiratory syndrome, a viral illness that first emerged in China in November 2002 and spread through international travel to 29 countries. Studies using mouse models of that virus have shown that the olfactory tract, or the pathway for communication of odors from the nose to the brain, was a gateway into the central nervous system and infection of the brain.