Social exclusion (ostracism) is a major psychosocial factor contributing to the development and persistence of psychiatric disorders and is also related to their social stigma. However, its specific role in different disorders is not evident, and comprehensive social psychology research on ostracism has rather focused on healthy individuals and less on psychiatric patients. Here, we systematically review experimental studies investigating psychological and physiological reactions to ostracism in different responses of psychiatric disorders. Moreover, we propose a theoretical model of the interplay between psychiatric symptoms and ostracism. A systematic MEDLINE and PsycINFO search was conducted including 52 relevant studies in various disorders (some of which evaluated more than one disorder): borderline personality disorder (21 studies); major depressive disorder (11 studies); anxiety (7 studies); autism spectrum disorder (6 studies); schizophrenia (6 studies); substance use disorders (4 studies); and eating disorders (2 studies). Psychological and physiological effects of ostracism were assessed with various experimental paradigms: e.g., virtual real-time interactions (Cyberball), social feedback and imagined scenarios. We critically review the main results of these studies and propose the overall concept of a vicious cycle where psychiatric symptoms increase the chance of being ostracized, and ostracism consolidates or even aggravates psychopathology. However, the specificity and stability of reactions to ostracism, their neurobiological underpinnings, determinants, and moderators (e.g., attachment style, childhood trauma, and rejection sensitivity) remain elusive.