Neuropsychology of the Prodrome to Psychosis in the Napls Consortium: Relationship to Family History and Conversion to Psychosis

Abstract

Context: Early detection and prospective evaluation of clinical high-risk (CHR) individuals who may develop schizophrenia or other psychotic disorders is critical for predicting psychosis onset and for testing preventive interventions.Objectives: To elucidate the neuropsychology of the CHR syndrome, to determine the association of neuropsychological function with conversion to psychosis and family history of psychosis, and to examine whether baseline neuropsychological functioning predicts subsequent psychosis.Design: Longitudinal study with 2 1 ⁄2 years of follow-up.Setting: Eight centers participating in the North American Prodrome Longitudinal Study.Participants: Three hundred four prospectively identified CHR individuals meeting Structured Interview for Prodromal Syndromes criteria, 52 non-CHR persons with a family history of psychosis in first-or second-degree relatives (family high-risk group), and 193 normal controls with neither a family history of psychosis nor a CHR syndrome, all of whom underwent baseline neuropsychological evaluations. Main Outcome Measures:A neurocognitive composite score, 8 individual neuropsychological measures, an IQ estimate, and high-risk status.Results: Global ("composite") neuropsychological functioning was comparably impaired in the CHR and family high-risk groups compared with controls, but profiles differed significantly between groups. Neuropsychological functioning in the CHR group was significantly lower in persons who progressed to psychosis than in those who did not and was worst in the subgroup with a family history of psychosis. Tests of processing speed and verbal learning and memory were most sensitive in discriminating CHR individuals from controls, although reductions were less severe than in established schizophrenia. Neuropsychological functioning did not contribute uniquely to the prediction of psychosis beyond clinical criteria, but worse verbal memory predicted more rapid conversion.Conclusions: These findings document that CHR individuals have significant neuropsychological difficulties, particularly those who later develop psychosis. This dysfunction is generally of moderate severity but less than in first-episode schizophrenia, suggesting that further decline may occur after baseline CHR assessment.

Predicting Risk and the Emergence of Schizophrenia

“…Several different groups have demonstrated verbal and spatial working memory deficits in UHR samples. [128][129][130][131][132][133] Wood and colleagues, 134 for example, demonstrated spatial working memory deficits in an Australian sample of 38 UHR patients using a block-tapping test. Smith and colleagues 135 have also shown spatial working memory deficits in an American sample of 8 UHR patients.…”

“…Attention deficits have now been demonstrated many times across different studies. [131][132][133][134] Executive function Tasks, such as the Wisconsin Card Sorting Test (WCST) and the Tower of Hanoi, are among the most commonly used measures of executive functioning in UHR samples. Several groups have demonstrated executive function deficits in UHR patients.…”

“…In the largest study to date of neurocognitive functioning in patients with prodromal syndromes, Seidman and colleagues 133 found that processing speed, measured with a symbol-coding task, was the most pronounced of all neurocognitive deficits. Most recently, Carrion and colleagues 137 have also shown in a large sample of American UHR patients that not only were processing speed deficits especially pronounced relative to most other neurocognitive deficits but also processing speed deficits were uniquely predictive of social and role functioning, independent of positive psychotic symptoms.…”

Review paper. Neuropsychological dimension of schizophrenia - evaluation possibilities and therapeutic implications

“…Both numerous reports in the literature and clinical observations of patients with schizophrenia lead to the conclusion that cognitive impairment in most cases is preceded by the outbreak of psychosis [48,49,50,51,52]. Moreover, its severity in patients with the first episode of schizophrenia may be associated with the time elapsed since the onset of psychotic symptoms to undertaking of appropriate treatment [53].…”

“…Zarówno liczne doniesienia w literaturze, jak i obserwacje kliniczne osób chorych na schizofrenię pozwalają na stwierdzenie, że zaburzenia funkcji poznawczych w większości przypadków wyprzedzają wybuch psychozy [48,49,50,51,52] a ich nasilenie u osób z pierwszym epizodem schizofrenii może być związane z czasem, jaki upłynął od wystąpienia pierwszych objawów psychotycznych do podjęcia stosownego leczenia [53]. Tę niedomogę poznawczą, szczególnie w zakresie pamięci słownej, funkcji wykonawczych, pamięci operacyjnej i pamięci globalnej już w pierwszym epizodzie psychotycznym potwierdzają dane z badań Bildera [48].…”