title: The course of cognitive functioning after first-episode of psychosis: A six month follow-up study.
abstract: Our aim with the present study was to evaluate rank-order and mean-level cognitive functioning stability among first-episode psychosis (FEP) patients, measured using the Cambridge Neuropsychological Test Automated Battery (CANTAB), over a six month period. We also aimed to examine longitudinal measurement invariance and identify factors-such as age, gender, educational level, treatment and psychopathological change scores-potentially linked to cognitive change among patients. In addition, correlations between objectively measured and subjectively evaluated cognitive functioning were estimated. Neuropsychological assessments were administered to 85 patients after the initial stabilisation of their psychosis; 82 of the patients were retested. Subjectively perceived cognitive functioning was measured using a subscale derived from the Estonian version of the Subjective Well-Being Under Neuroleptic Scale (SWN-K-E). On average, executive functioning and processing speed improved significantly, while memory test scores decreased significantly, over time. Very high rank-order stability (r=0.80 to 0.94, p<0.001) was observed with all measured ability scores. Confirmatory factor analysis revealed the loadings of a single (broad ability) factor model were equal across both measurement occasions, but the lack of intercept invariance suggested that mean-level comparisons are more appropriately carried out at a subtest level. On average psychopathology scores and antipsychotics doses declined over time, with the latter also significantly correlating with better executive functioning. Gender was a significant moderator of some domains of cognitive performance, and decline tended to be somewhat more pronounced for women. The results also indicated the lack of any relationship between objective and subjective measurements of cognitive functioning.
authors.affiliation: Psychiatry Clinic of Tartu University Hospital, Tartu, Estonia. Electronic address: Liina.Haring@kliinikum.ee.
authors.forename: Liina
authors.initials: L
authors.lastname: Haring
authors.affiliation: Department of Psychology, University of Edinburgh, Edinburgh, UK; Department of Psychology, University of Tartu, Tartu, Estonia. Electronic address: Rene.Mottus@ed.ac.uk.
authors.forename: René
authors.initials: R
authors.lastname: Mõttus
authors.affiliation: Psychiatry Clinic of Tartu University Hospital, Tartu, Estonia. Electronic address: Karolin.Kajalaid@kliinikum.ee.
authors.forename: Kärolin
authors.initials: K
authors.lastname: Kajalaid
authors.affiliation: Psychiatry Clinic of Tartu University Hospital, Tartu, Estonia. Electronic address: Kadri.Koch@kliinikum.ee.
authors.forename: Kadri
authors.initials: K
authors.lastname: Koch
authors.affiliation: Psychiatry Clinic of Tartu University Hospital, Tartu, Estonia. Electronic address: Kart.Uppin@kliinikum.ee.
authors.forename: Kärt
authors.initials: K
authors.lastname: Uppin
authors.affiliation: Psychiatry Clinic of Tartu University Hospital, Tartu, Estonia; North Estonia Medical Centre, Department of Psychiatry, Tallinn, Estonia; Centre for Mental Health, Imperial College London, UK. Electronic address: e.maron@imperial.ac.uk.
authors.forename: Eduard
authors.initials: E
authors.lastname: Maron
authors.affiliation: Institute of Biomedicine and Translational Medicine, University of Tartu, Tartu, Estonia; Centre of Excellence for Genomics and Translational Medicine, University of Tartu, Tartu, Estonia. Electronic address: Eero.Vasar@ut.ee.
authors.forename: Eero
authors.initials: E
authors.lastname: Vasar
mesh_terms: D000293:Adolescent; D000328:Adult; D003072:Cognition Disorders / Q000175:diagnosis* / Q000209:etiology*; D005163:Factor Analysis, Statistical; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008297:Male; D008570:Memory, Short-Term; D008875:Middle Aged; D009483:Neuropsychological Tests; D011569:Psychiatric Status Rating Scales; D011618:Psychotic Disorders / Q000150:complications*; D055815:Young Adult
keywords: CANTAB; Cognitive dysfunction; First-episode psychosis; Measurement invariance; SWN-K