Abstract
Background Delusions are a significant feature of mental illnesses and can occur in many clinical conditions (Maher, 2001) yet the standard clinical definition (American Psychiatric Association. DSM-5 Task Force, 2013) is highly contentious. Much of the literature holds elements such as bizarreness of content and incorrigibility of belief as defining factors of delusion. However, on closer inspection, delusions are not so easy to pin down. The difficulty in defining delusion is not a new one as “…we are all capable of having convictions and it is a universal human characteristic to hold on to our own mistaken judgements.” (Jaspers, 1963, p.63). Objective I intend to highlight some of the difficulties associated with the definition of delusion and perhaps clarify the phenomenology. Methodology I examine some of the philosophical, psychological and psychiatric literature with regard to the definition of delusion. I also consider my experience of my own mental activity and experiences from my therapeutic work. Results/Conclusion I identify that delusions are a heterogeneous group and that there may be more than one ‘class’ of delusion. I also show that delusions are multi-dimensional with characteristics on a continuum with normal beliefs and that further research is needed to clarify the phenomenology