Do schizotypy dimensions reflect the symptoms of schizophrenia?

Elizabeth Hx Thomas; Susan L Rossell; Eric J Tan; Erica Neill; Tamsyn E Van Rheenen; Sean P Carruthers; Philip J Sumner; Stephanie Louise; Kiymet Bozaoglu; Caroline Gurvich

doi:10.1177/0004867418769746

Do schizotypy dimensions reflect the symptoms of schizophrenia?

Aust N Z J Psychiatry. 2019 Mar;53(3):236-247. doi: 10.1177/0004867418769746. Epub 2018 Apr 28.

Authors

Elizabeth Hx Thomas¹, Susan L Rossell^{1

2

3}, Eric J Tan^{1

2

3}, Erica Neill^{3

4}, Tamsyn E Van Rheenen^{1

2

4}, Sean P Carruthers^{1

2}, Philip J Sumner^{1

2}, Stephanie Louise^{1

2

5}, Kiymet Bozaoglu^{6

7}, Caroline Gurvich¹

Affiliations

¹ 1 Cognitive Neuropsychiatry Laboratory, Monash Alfred Psychiatry Research Centre (MAPrc), The Alfred Hospital and Central Clinical School, Monash University, Melbourne, VIC, Australia.
² 2 Centre for Mental Health, Faculty of Health, Arts and Design, School of Health Sciences, Swinburne University of Technology, Melbourne, VIC, Australia.
³ 3 St Vincent's Mental Health, St Vincent's Hospital, Melbourne, VIC, Australia.
⁴ 4 Melbourne Neuropsychiatry Centre, Department of Psychiatry, The University of Melbourne and Melbourne Health, Melbourne, VIC, Australia.
⁵ 5 Centre for Forensic Behavioural Science, Faculty of Health, Arts and Design, Swinburne University of Technology, Melbourne, VIC, Australia.
⁶ 6 Bruce Lefroy Centre for Genetic Health Research, Murdoch Children's Research Institute, Melbourne, VIC, Australia.
⁷ 7 Department of Paediatrics, The University of Melbourne, Melbourne, VIC, Australia.

PMID: 29707955
DOI: 10.1177/0004867418769746

Abstract

Objective: The personality characteristics and symptoms observed in schizophrenia are postulated to lie on a continuum, with non-clinical manifestations referred to as schizotypy. High schizotypy behaviours are argued to correspond with the three main clusters of symptoms in schizophrenia: positive, negative and cognitive/disorganised symptoms, yet there is limited empirical evidence to support this. This study aimed to investigate whether schizotypy dimensions significantly correlate with their respective schizophrenia symptomatology in the largest sample to date.

Methods: A total of 361 adults (103 patients with schizophrenia/schizoaffective disorder and 258 healthy controls) were assessed for schizotypy using the Oxford-Liverpool Inventory of Feelings and Experiences. The MATRICS Consensus Cognitive Battery supplemented by the Stroop task and Wisconsin Card Sorting Test was administered to all participants to obtain objective measurements of cognition. Schizophrenia symptomatology was assessed using the Positive and Negative Syndrome Scale in patients only.

Results: The results demonstrated significant correlations between the Oxford-Liverpool Inventory of Feelings and Experiences positive and negative subscales and their respective Positive and Negative Syndrome Scale subscales only, indicating that positive and negative schizotypy dimensions across patients and controls accurately reflect the respective schizophrenia symptomatology observed in patients. Cognitive performance did not correlate with cognitive/disorganised symptom dimensions of the Oxford-Liverpool Inventory of Feelings and Experiences or the Positive and Negative Syndrome Scale, indicating that cognitive impairment is an independent symptom dimension that requires objective cognitive testing.

Conclusion: Collectively, the findings provide empirical evidence for the continuum theory and support the use of schizotypy as a model for investigating schizophrenia.

Keywords: Psychosis; cognitive disorganisation; fully dimensional model; introvertive anhedonia; unusual experiences.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Adult
Case-Control Studies
Female
Humans
Male
Middle Aged
Neuropsychological Tests
Psychiatric Status Rating Scales
Schizophrenia / diagnosis*
Schizophrenic Psychology*
Schizotypal Personality Disorder / diagnosis*
Schizotypal Personality Disorder / psychology*
Stroop Test
Wisconsin Card Sorting Test
Young Adult