Are you interested in the nature and meaning of psychosis? This is an abstract of a study which compared the frequency, distress and intrusiveness of anomalous perceptual experiences in 336 subjects from the general population and 20 psychotic inpatients. 11% of the population sample scored above the mean of the psychotic patients’ sample. A factor analysis of the population data suggested three clusters — one involving “clinically psychotic-like” phenomena; one attributable to temporal lobe epilepsy and other seizure-like processes; and a third “chemosensation” cluster largely involving olfactory and gustatory anomalous experiences. This suggested to the authors ‘that there are multiple contributory factors underlying anomalous perceptual experience and the “psychosis continuum.” ‘
I beg to differ. They are really not demonstrating any “psychosis continuum,” since they use ‘psychosis’ as a wastebasket term synonymous with anomalous perceptual experience. All they are demonstrating is how virtually meaningless it is to talk about psychosis in that way, and that is why their headline finding — that a proportion of the general population score higher on their measure than those hospitalized for psychosis — is less surprising than it sounds. If you lump together a heterogeneous grouping of patients with ‘psychosis’, only some of them will be off the charts in terms of anomalous perceptual experiences, because having anomalous perceptual experiences is only one way of being psychotic. Yes, some psychotics have hallucinations, in which they cannot assess the reality or meaning of various perceptual experiences they are having. But others’ psychoses consist primarily of a disturbance in the content of their thought, i.e. so-called delusional thinking. Finally, some people are considered psychotic because of a disturbance in the form, not the content, of their thought processes, with profoundly disorganized, fractured, incoherent and illogical reasoning.
Patients with diverse disturbances of their mental processes and brain function may be given the same psychotic diagnosis despite the fact that they are probably undergoing very distinct disease processes, psychological or neurophysiological alterations. For example, considering the quintessential psychotic disorder, schizophrenia, different thinkers have defined it differently based on different clusters of core symptoms (among them Kurt Schneider, responsible for the so-called “Schneiderian signs” alluded to in this article). They are all talking about schizophrenia but probably pointing at different schizophrenics.
Moreover, we have come to realize that none of these supposedly defining core symptom clusters are pathognomonic of schizophrenia per se and they can occur in many other psychotic illnesses — mania, psychotic depression, organic psychotic disorders including those arising in epilepsy, toxic and metabolic psychoses, etc. — as well.
Now we reach the next juncture, in which it is suggested that the same anomalous experiences occur in a population without psychiatric diagnosis as well. First of all, that may not be strictly true. Most epidemiological studies have found a significant incidence of psychiatric illness, undiagnosed, in a randomly selected population at large. It is a truism that only the mental health profession thinks that it treats most of the mental illness in the population.
If the authors are suggesting that what really distinguishes a psychiatric patient from a member of the general population undergoing anomalous perceptual experience is how much distress the experience causes and what sort of sense the person can make of their experience, they are coming closer to my notion of what the core deficits are in psychotic experience. As I see it, these embody fundamental disturbances in the sense of the self, its boundaries, and its relationship to the world beyond those boundaries. Such disturbances render anomalous experiences utterly incomprehensible and terrifying, literally unendurable. Even perceptual experiences which others of us might consider not the least bit anomalous but rather ordinary cannot be made sense of if you do not know if they are coming from within you or outside yourself, whether they are providing information about your internal or the external environment, whether they are shared by others or uniquely experienced by yourself, etc. etc.
In a sense, this study is illustrative of all that is wrong with modern psychiatry. Yes, psychiatry is supposed to inhabit the province of subjective experience. But a descriptive focus on symptoms alone defines nothing when the self is written out of the equation.