In a recent editorial, Kelleher & Cannon (Reference Kelleher and Cannon2011) reviewed the state of research on psychotic experiences in the general population. The studies reviewed converged in showing that a large number of subjective experiences and beliefs with some degree of affinity with psychotic symptoms can be found in the general population (Kelleher & Cannon, Reference Kelleher and Cannon2011). These unusual subjective experiences are often referred to as psychotic-like experiences (PLEs). The majority of the research in the field assumes that PLEs constitute a soft, subthreshold phenotype on a continuum with overt psychotic symptoms. This assumption is based on epidemiological research findings showing that PLEs are relatively widespread in the general population and may contribute to enhance psychosis risk (van Os et al. Reference van Os, Linscott, Myin-Germeys, Delespaul and Krabbendam2009). However, their prevalence is largely estimated through self-report questionnaires that merely record the frequencies of occurrence of experiences similar in content to delusions and hallucinations. This may be quite problematic, since allegedly important features that qualify the psychopathological severity of a psychotic experience, such as its appraisal and the related distress, are not taken into account. In this way any kind of unusual subjective experience is considered contributing equally to the risk of developing clinical signs of psychosis regardless of content, personal meaning or attribution, associated emotions and social context. Nontheless, some evidence suggests that PLEs are not necessarily psychotic. The first evidence comes from the research conducted on the multidimensionality of the unusual subjective experiences, which found that the associated distress, preoccupation and conviction are better predictors of psychosis risk (Lincoln, Reference Lincoln2007). The second evidence comes from the investigation of the so-called ‘happy schizotype’, those individuals with accentuated levels of unusual subjective experiences yet not displaying any sign of overt psychopathology (McCreery & Claridge, Reference McCreery and Claridge2002).
In consideration of the multidimensional characteristics of unusual subjective experiences and their limited predictive value for psychopathology it may be worthwhile for clinicians and researchers to reconsider some of the underpinnings of this research field. Indeed, the commonly used term PLE may suggests that the experience has a truly ‘psychotic-like’ implication in itself, whereas this is true only for a minority of these experiences. Thus, the expression PLE might be more appropriately circumscribed to those unusual subjective experiences that – although still subclinical – have a self-perceived symptomatic nature because of increased distress, impairment or disability. As a matter of fact, the mainstream emphasis on currently broadly defined PLEs as a measure of psychosis-proneness is overstated if the subjective appraisal of the experience is not considered. Moreover, the role of emotions has been suggested to be important in moderating the severity of the distress associated with unusual subjective experiences (Freeman & Garety, Reference Freeman and Garety2003). Hence, future attempts to define the clinical value of unusual subjective experiences should take into account not only their frequency but also consider associated relevant dimensions. As advocated by David (Reference David2010), this may prove useful not only to stimulate the debate on psychotic symptoms but also to contribute to our understanding of the pathological mechanisms of psychosis.
Declaration of Interest
None.
