Associations of differential schizotypal dimensions with executive working memory: A moderated-mediation analysis.
Increased schizotypal traits are observed in a percentage of the general population and in the schizophrenia-spectrum and have been associated with impairments in working memory. In this study we examined the effects of four schizotypal dimensions [Negative (NegS), Paranoid (ParS), Cognitive-Perceptual (CPS), Disorganized (DiS)] on executive working memory (EWM), as mediated by set-shifting, planning and control inhibition. We also examined whether these associations are moderated by family-history of psychosis.



Our sample consisted of 110 unaffected first-degree relatives of schizophrenia-spectrum patients and 120 control individuals. Schizotypy was assessed with the Schizotypal Personality Questionnaire. Participants were also tested with the Letter-Number Sequencing, Wisconsin Card Sorting, Stroop Color-Word and Stockings of Cambridge tasks. The effects of set-shifting, control inhibition and planning on the relationship between schizotypy and EWM were examined with mediation analyses. Moderated-mediation analyses examined potential moderating effects of group membership (unaffected relative/community participant).



All mediators were significant in the relationship between NegS and EWM. The effects of ParS were mediated only by set-shifting and planning. Planning and control inhibition were the only significant mediators on the effects of CPS and DiS on EWM, respectively. The moderated-mediation analyses revealed that these findings apply only in the community group.



We found that the effects of different schizotypal dimensions on EWM are mediated by other cognitive processes in individuals without personal/family history of psychosis. This is probably due to either more severe impairments in the cognitive processes of the relatives or restrictions in our sample and study-design.
Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece.
Chrysoula
C
Zouraraki
Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece.
Ioannis
I
Tsaousis
Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece.
Penny
P
Karamaouna
Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece.
Leda
L
Karagiannopoulou
Department of Psychiatry, Department of Genetics and Genomic Sciences, Institute for Genomics and Multiscale Biology, Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
Panos
P
Roussos
Department of Psychiatry and Behavioral Sciences, Faculty of Medicine, University of Crete, Heraklion, 71003, Crete, Greece.
Panos
P
Bitsios
Department of Psychology, University of Crete, Rethymno, 74100, Crete, Greece. Electronic address: sgiakoumaki@uoc.gr.
Stella G
SG
Giakoumaki
D000293:Adolescent; D000328:Adult; D005190:Family / Q000523:psychology*; D005192:Family Health; D005260:Female; D006801:Humans; D008297:Male; D008569:Memory Disorders / Q000150:complications / Q000523:psychology*; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests; D011618:Psychotic Disorders / Q000523:psychology; D012569:Schizotypal Personality Disorder / Q000150:complications / Q000523:psychology*; D055815:Young Adult