Review article
The concept of schizotypy and significance of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE)

Schizotypy, perceived as a personality trait, has both positive and negative aspects. Schizotypal disorder, as a diagnostic category, has been included in schizophrenia spectrum disorders in the American Diagnostic and Statistical Manual (DSM-5) as well as in the International Classification of Diseases (ICD-10). A number of genetic, biological, and neuropsychological similarities between persons with schizotypy and patients with schizophrenia have been shown. Schizotypal features occur in greater frequency in bipolar disorder (BD) compared with healthy subjects. A popular tool for measuring schizotypy is the Schizotypal Personality Questionnaire created by Raine in 1991 as well as scales created by Chapman and by Venables.

This article presents the origins of the Oxford-Liverpool Inventory of Feelings and Experiences (O-LIFE) created by Claridge and co-workers and describes its stucture, consisting of four dimensions: unusual experiences, cognitive disorganisation, introvertive anhedonia and impulsive nonconformity. Studies using O-LIFE demonstrated both internal consistency and reliability of the scale. Connections between the O-LIFE dimensions and cognitive processes in patients with schizophrenia and creativity in bipolar patients have been demonstrated. In patients with BD treated with lithium carbonate, a significant negative correlation between the quality of response to long-term treatment and schizotypal traits (particularly cognitive disorganisation) was found. In genetic studies, associations between O-LIFE dimensions and polymorphisms of dopaminergic system and circadian rhythm genes were observed.

The O-LIFE is an important tool for measuring schizotypy. Studies using this scale may expand the knowledge on neuropsychological and neurobiological mechanisms in psychiatric disorders and in healthy subjects.