The prevalence of the biopsychosocial model in psychiatry highlights the importance of investigating the clinical significance of religiosity in patients with psychotic disorders. Due to the spiritual and supernatural nature of religious beliefs, distinguishing them from religious delusions is a challenging endeavour. The self-referential nature of the beliefs, the presence of concomitant psychiatric symptomatology and the effect on functionality seem to play a key role in differential diagnosis. Religious psychotic symptoms are common in clinical practice. The study of these symptoms often becomes difficult due to varying definitions, the fluctuation they present over time and space and the strong influences of the social and cultural environment on them. There seems to be a positive correlation between religiosity and the occurrence of religious delusions in psychotic patients, but it is not clear that this indicates a causal relationship. The content of religious delusions seems to be significantly influenced by the immediate social environment rather than cultural background of the individual, as well as by the beliefs and attitudes of the patient's family environment. Religious delusions are characterized by increased conviction and pervasiveness, permeating to a greater extent the individual's whole experience. Their presence is associated with more severe symptoms, higher medication dosage, and poorer prognosis. The increased severity of psychosis with religious content symptomatology seems to be associated with genetic factors and greater genetic load. In addition, the increased duration of untreated psychosis is a determinant of prognosis. This may reflect a reduced alertness of the immediate environment of patients who develop psychotic symptoms with religious content for the first time. Other important prognostic factors are patients' lack of adherence to treatment, their greater resistance to psychiatric approach of the disorder and their exclusion from religious communities, as well as the special characteristics of religious delusions, which seem more corrosive to the patients' psyche than other delusions. Religion and spirituality are prominent in the lives of the majority of patients with psychosis, but they are often underestimated in clinical practice. Raising the awareness of mental health professionals on issues of a religious and spiritual nature can be beneficial in both preventing and treating psychotic disorders.
Keywords: delusions; psychotic disorders; religiosity; religious delusions.