Continuity between normal and psychotic experience

[Turion]

Borrowed from the book Cognitive Behaviour Therapy for Psychosis

Traditionally it has been assumed that psychotic symptoms are unique signs of biological pathology which are discontinuous with normal experience and therefore by definition bizarre and abnormal. However there are several observations that indicate that it may be more valid to view normal experience and psychosis as existing at two ends of a continuum. If one takes a longitudinal perspective it is clear that psychotic symptoms wax and wane in severity over the course of a disorder. Over time frank hallucinations may become mild abnormalities in the experience of thoughts, and delusional beliefs may become eccentric ideas. Conversely, frank symptoms may be preceded by milder experiential anomalies which become apparently less and less understandable as acute psychotic symptoms (eg experiences of deja vu, beliefs in telepathy and hallucinations) occur in a substantial proportion of  people in the normal population (around 15-20%) as well as occuring amongst people with frank psychotic disorders. Experimental studies have demonstrated that there are parallels between the performance of people who report schizotypal experiences, and people who meet diagnostic criteria for schizophrenia on a variety of cognitive tasks. There may be commonalities between the processes which give rise to both types of experience. Lastly, hallucinations and other psychotic experiences may be induced in normal people when put under unusual conditions (eg under hypnotism, sensory deprivation, very sever stress, disorientation, etc).

Collectively these findings suggest that it may be useful to think of frank psychosis as a more sever manifestation of some anomalies in belief, thought and experience that may affect many normal people at some time or another. The assumption of a continuity between normality and psychosis has important clinical implications. It opens the way for a group of therapeutic techniques that focus on reducing the stigma and anxiety often associated with the experience of psychotic symptoms and with diagnostic labelling. These approaches have been described as normalising strategies, which involve explaining and demystifying the psychotic experience. They may involve suggesting to patients that their experiences are not strange and un-understandable, but are common to many people, and even found amongst people who are relatively normal and healthy. Normalisong strategies can help instill and decrease anxiety and stigma which may be associated with the experience of psychotic symptoms. The reassuring benefits of these relatively subtle interventions can be striking.