Correlations between fMRI activation and individual psychotic symptoms in un-medicated subjects at high genetic risk of schizophrenia.

Background: It has been proposed that different types of psychopathology in schizophrenia may reflect distinguishable pathological processes. In the current study we aimed to address such associations in the absence of confounders such as medication and disease chronicity by examining specific relationships between fMRI activation and individual symptom severity scores in un-medicated subjects at high genetic risk of schizophrenia.

Methods: Associations were examined across two functional imaging paradigms: the Hayling sentence completion task, and an encoding/retrieval task, comprising encoding (at word classification) and retrieval (old word/new word judgement).

Event-related fMRI of word classification and successful word recognition in subjects at genetically enhanced risk of schizophrenia.

Background: Verbal declarative memory is a core deficit in schizophrenia patients, seen to a lesser extent in unaffected biological relatives. Neuroimaging studies suggest volumetric differences and aberrant function in prefrontal and temporal regions in schizophrenia patients compared to controls. These deficits are also reflected in the small number of similar investigations in unaffected biological relatives.

Neuropsychological performance over time in people at high risk of developing schizophrenia and controls.

Background: Neuropsychological assessments of relatives of schizophrenics have shown subtle impairments in verbal memory, executive and intellectual function, which are stable in those beyond the age of maximum risk for the disorder. We sought to: (1) determine baseline neurocognitive predictors of psychosis, and (2) compare performance over time between relatives within the age of maximum risk, and controls.

Methods: (1) and (2) were examined in 118 individuals at familial high risk of schizophrenia (HR) and 30 controls (C), using one-way analyses of variance (ANOVAs) and repeated measures analyses of covariance (ANCOVAs), controlling for intelligence quotient, time between and number of assessments, and correcting for multiple comparisons.

Declarative memory in unaffected adult relatives of patients with schizophrenia: a systematic review and meta-analysis.

Despite evidence for diverse neuropsychological impairment in schizophrenia, verbal declarative memory has emerged as a core deficit in the disorder. Similar but less marked impairments have been demonstrated in unaffected biological relatives of patients with schizophrenia, but the nature and extent of the memory impairment in relatives compared to controls is unclear. We have conducted a systematic review and meta-analysis of the literature investigating declarative memory in unaffected biological relatives of schizophrenics and controls, with the aim of quantifying memory deficits in relatives.

Neural correlates of enhanced genetic risk for schizophrenia.

Schizophrenia is a disabling psychotic disorder characterized by hallucinations, delusions, and impaired functioning in many aspects of everyday life. The established condition generally becomes manifest in early adulthood, and evidence suggests that one of the most important risk factors for developing the disorder is inherited vulnerability. The established illness has been shown to be associated with deficits in many domains of cognitive function, along with structural and functional brain abnormalities, most notably in pre-frontal and temporal lobes.