ABSTRACT
Psychological models of delusions reflect pragmatic approach, and considers multi-dimensional in terms of distress, conviction, preoccupation and interference with functioning, and operating on a continuum with non-diagnosable or non-clinical beliefs. Both population and lab studies have found delusions and delusion-like thinking in non-clinical participants associated with higher levels of negative effect and poor psychological well-being as well as cognitive biases in multiple domains. Further classifications are commonly used in the psychiatric literature and may seem in formal assessments, although are not part of the diagnostic canon. It is also worth noting that delusions are typically more common in neurological patients than the general population, with dementia having a particularly high prevalence. There is a similar picture for common delusions that tend to present initially to non-psychiatric specialties, such as delusional parasitosis. Similarly, scales for assessing risk and other factors specifically related to delusions are scarce, with the Maudsley Assessment of Delusions Schedule being a notable exception.
