Nonverbal delayed recognition in the relatives of schizophrenia patients with or without schizophrenia spectrum

Abstract

Background: There is increased interest in the study of cognitive deficits as possible endophenotypic markers for schizophrenia. The main goal of this study was to determine how familiality and schizophrenia spectrum personality symptomatology are related to performance of auditory and visuospatial delayed recognition memory tasks.

Methods: The study sample consisted of 162 subjects divided into five groups. The groups included 39 patients with a DSM-IV diagnosis of schizophrenia or schizophreniform disorder; first-degree relatives of schizophrenia patients, 22 with and 31 without schizophrenia spectrum personality traits; and healthy control subjects with no family history of psychosis, 22 with and 48 without schizophrenia spectrum traits. Auditory and visuospatial delayed recognition memory performance was assessed.

Results: Significant differences were observed between patients and healthy control subjects in both auditory [F(1,79) = 7.358 p = .008] and visual [F(1,47) = 34.67, p < .001] delayed recognition tasks. When comparing the four non-patient groups, auditory and visuospatial discriminability decreased as a function of familiality of schizophrenia (p < .05). Deficits were more pronounced in relatives with schizophrenia spectrum traits [auditory d = .7114; visual d = 1.0199].

Conclusions: A biological relationship to schizophrenia increases the likelihood of impaired delayed recognition memory. Likewise, poorer performance is associated with schizophrenia spectrum phenotype only when combined with familiality.

Figure 1

Sample of an abstract, non-namable figure

Figure 2

Mean discriminability (A′) and standard error for auditory nonverbal recognition in non-clinical groups. With an A′ mean of (0.6139±.187) the group of SSP relatives demonstrated the poorest nonverbal auditory discriminability. Cohen’s d calculations reflect moderate effect of both groups of family members without (d=0.6056) and with SSP (d=0.7114) traits when compared to controls, thus supporting the main effect of family reported by the ANOVA analysis. Moderate effect sizes were also observed between SSP community subjects and family members with (d=0.6418) and without (d=0.7429) SSP traits. The standardized difference between both groups from the community (with and without SSP) was close to zero (d=0.0062).

Figure 3

Mean discriminability (A′) and standard error for visuospatial nonverbal recognition in non-clinical groups. With a mean A′ score of (0.6513±.081) SSP relatives demonstrated the most marked impairment among the 4 non-patient groups. Cohen’s d calculations revealed the largest effect size between healthy controls and SSP relatives (d=1.0199). In addition, there were large and moderate effect sizes when comparing SSP relatives to non-SSP relatives (d=0.8370), and to community SSP subjects (d=0.6688), respectively. When compared to healthy controls, SSP community subjects (d=0.239) and non-SSP relatives (d=0.2704) had small effect sizes.