Addiction is a biopsychosocial disorder characterized by repeated use of drugs, or repetitive engagement in a behavior such as gambling, despite harm to self and others. According to the "brain disease model of addiction," while a number of psychosocial factors contribute to the development and maintenance of addiction, a biological process that is induced by repeated exposure to an addictive stimulus is the core pathology that drives the development and maintenance of an addiction. Many scholars who study addiction argue that the brain disease model is incomplete and misleading.