Patients with long COVID-19 in the U.S. report far higher rates of brain fog, depression and cognitive symptoms than patients in countries such as India and Nigeria, according to a large international study led by Northwestern Medicine.

The authors note that higher reported symptom burden in the U.S. may reflect lower stigma and greater access to neurological and mental health care, rather than more severe disease.

The study, the first cross-continental comparison of long COVID neurological manifestations, tracked more than 3,100 adults with long COVID evaluated at academic medical centers in Chicago; Medellín, Colombia; Lagos, Nigeria; and Jaipur, India.