Researchers from the University of California (UC), US, found that among the vaccinated population, people who have a history of certain psychological conditions, face an increased risk of breakthrough infection of Covid-19. The findings of the study, published in the journal JAMA Network Open, pointed out that patients over 65 with substance abuse, psychotic disorders, bipolar disorder, adjustment disorder and anxiety, faced increased risks of up to 24 percent for breakthrough COVID. The researchers said that they tracked data from  more than 2.5 lakh US Department of Veterans Affairs patients to find that breakthrough infections are not simply a result of socio-demographic factors or pre-existing conditions.