SEEING IMPOSTORS: When loved ones suddenly aren’t. “Capgras delusion can be brought about by a variety of conditions — changes in brain chemistry associated with different mental illnesses, or physical trauma to the brain — but the delusion always involves the distinct feeling that the people around you have been replaced by impostors. While they may look and act just like the real person, some essence of the person is missing, almost as though ‘the soul of the person isn’t in there,’ Berman says.”