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.

Hippocampal subfields and visuospatial associative memory across stages of schizophrenia-spectrum disorder

“…Thus, although the recent-onset patients demonstrate visuospatial associative memory impairments, these appear to be milder than those observed in chronic patients. Although previous studies have also identified visuospatial associative memory deficits in individuals with chronic schizophrenia (Wood et al ., 2002; Stip et al ., 2005; Donohoe et al ., 2008), prior studies of recent-onset patients found preserved functioning in this domain (Wood et al ., 2002; Barnett et al ., 2005; Wannan et al ., 2018), with deterioration occurring only after illness onset (Haring et al ., 2017; Wannan et al ., 2018). One potential explanation for the visuospatial associative memory deficit in our recent-onset group is their longer duration of illness compared with previous studies (Wood et al ., 2002; Wannan et al ., 2018).…”

“…Memory impairments are considered to be a core cognitive dysfunction in schizophrenia, with patients exhibiting deficits across a wide range of memory tasks relative to healthy controls. While it has previously been suggested that memory ability is stably impaired in individuals with schizophrenia (Bora and Murray, 2013), recent longitudinal evidence indicates that one particular type of memory, visuospatial associative memory, is preserved in individuals with first-episode psychosis, with deterioration occurring only as the illness progresses (Haring et al ., 2017; Wannan et al ., 2018). It is, therefore, possible that deficits in visuospatial associative memory observed in chronic patients (Wood et al ., 2002; Stip et al ., 2005; Donohoe et al ., 2008) are related to stage-specific brain abnormalities in regions associated with this ability (Bartholomeusz et al ., 2017).…”