Prospective Memory Performance in Non-Psychotic First-Degree Relatives of Patients with Schizophrenia: A Controlled Study

Abstract

ObjectiveWe aimed at investigating prospective memory and its socio-demographic and neurocognitive correlates in non-psychotic, first-degree relatives (FDRs) of patients with schizophrenia compared to patients with first episode schizophrenia (FES), and healthy controls (HCs).MethodsForty-seven FES patients, 50 non-psychotic FDRs (23 offspring and 27 siblings) of patients with chronic schizophrenia (unrelated to the FES group) and 51 HCs were studied. The Chinese version of the Cambridge Prospective Memory Test (C-CAMPROMPT) was used to measure time-based prospective memory (TBPM) and event-based prospective memory (EBPM) performance. Other cognitive functions (involving respective memory and executive functions) were evaluated with standardized tests.ResultsAfter controlling for basic demographic characteristics including age, gender and educational level, there was a significant difference between FDRs, FES and HCs with respect to both TBPM (F(2,142) = 10.4, p<0.001) and EBPM (F(2,142) = 10.8, p<0.001). Multiple linear regression analyses revealed that lower scores of the Hopkins Verbal Learning Test-Revised (HVLT-R) and the STROOP Word-Color Test (SWCT) contributed to TBPM impairment, while lower educational level and higher scores of the Color Trails Test-2 (CTT-2) contributed to EBPM deficit in FDRs.ConclusionsFDRs share similar but attenuated prospective memory impairments with schizophrenia patients, suggesting that prospective memory deficits may represent an endophenotype of schizophrenia.

Longitudinal changes in prospective memory and their clinical correlates at 1-year follow-up in first-episode schizophrenia

“…PM deficits have been consistently confirmed in both chronic [ 17 – 26 ] and first-episode schizophrenia (FES) [ 27 – 29 ]. Non-psychotic first-degree relatives of schizophrenia patients show similar but attenuated PM impairments compared to patients suggesting that PM deficits may be an endophenotype of the illness [ 30 ].…”

“…In EBPM, the carrying out of an intended action is prompted by an external cue, while TBPM relies on the ability to perform an action at a specified time in the future [ 31 ]. PM is related to prefrontal-lobe functions in both schizophrenia patients and their first-degree relatives, but TBPM and EBPM may involve different neurocognitive processes [ 28 , 30 ].…”

Prospective memory in individuals with first‐episode schizophrenia: A two‐year longitudinal study

“…There is ample empirical evidence for the existence of PM impairments in patients with both first-episode and chronic schizophrenia (Ordemann et al, 2014). Despite strong evidence supporting that PM satisfies the illness association criterion for a putative trait marker (Gottesman & Gould, 2003), relatively few studies have investigated the other criteria for a putative trait marker, such as familial association (Lui et al, 2011b;Wang et al, 2010;Zhou et al, 2014) and state independence (Cheung et al, 2015;Zhou et al, 2017) of PM. Findings of previous familial studies are inconsistent, with two studies (Wang et al, 2010;Zhou et al, 2014) suggesting familial association of PM impairments, but one (Lui et al, 2011b) reporting negative results.…”

“…Despite strong evidence supporting that PM satisfies the illness association criterion for a putative trait marker (Gottesman & Gould, 2003), relatively few studies have investigated the other criteria for a putative trait marker, such as familial association (Lui et al, 2011b;Wang et al, 2010;Zhou et al, 2014) and state independence (Cheung et al, 2015;Zhou et al, 2017) of PM. Findings of previous familial studies are inconsistent, with two studies (Wang et al, 2010;Zhou et al, 2014) suggesting familial association of PM impairments, but one (Lui et al, 2011b) reporting negative results. On the other hand, previous longitudinal studies (Cheung et al, 2015;Zhou et al, 2017) have consistently suggested that timebased PM is more temporally stable than event-based PM, even when practice effect was controlled for, using parallel assessments of PM in the control group (Zhou et al, 2017).…”

Prospective Memory Performance in Persons With Schizophrenia and Bipolar Disorder and Healthy Persons

“…Compared with patients with schizophrenia, research on PM in clinically stable patients with bipolar disorder is at its early stage (Au et al, 2013;Chan et al, 2013;Zhou et al, 2014). In traditional psychiatric nosology, schizophrenia and bipolar disorder were viewed as two separate entities (Kraepflin, 1976).…”