Self-rated schizotypal cognitions, psychotic symptoms and the onset of schizophrenia in young people at high risk of schizophrenia.

OBJECTIVE: To examine the associations between the Rust Inventory of Schizotypal Cognitions (RISC) and psychotic symptoms measured by the Present State Examination (PSE) and to assess the predictive validity of the RISC for later onset of schizophrenia. METHOD: A total of 154 subjects at high risk for schizophrenia but who were currently well, 35 well controls and 28 first episode schizophrenic patients were assessed on specified PSE symptoms and completed the RISC. A subsample of the high risk group was subsequently monitored for onset of schizophrenia over 39 months. RESULTS: RISC scores at entry were significantly higher in subjects with psychotic symptoms on PSE. There were indications that high scorers on the RISC were likely to develop schizophrenia. However, less than half of those falling ill exhibited high RISC scores on entry. CONCLUSION: The RISC scale is highly associated with presence of psychotic symptoms on PSE and high scorers may be at increased risk of schizophrenia onset.

Sustained attention in young people at high risk for schizophrenia.

BACKGROUND: Sustained attention has been found to be impaired in individuals suffering from schizophrenia and their close relatives. This has led to the hypothesis that impaired sustained attention is an indicator of vulnerability to schizophrenia. METHODS: The Edinburgh High Risk Study used the Continuous Performance Test-Identical Pairs version (CPT-IP) to assess sustained attention in 127 high risk participants, 30 controls and 15 first-episode schizophrenic patients. A second assessment was completed by 59 high risk and 18 control participants 18 months to 2 years after the first. RESULTS: No differences in attentional capacity were found between the high risk and control groups and there was no association between genetic liability to schizophrenia and poor performance on the CPT-IP. Additionally, no association between occurrence of psychotic symptoms in the high risk group and impaired attentional capacity was found. CONCLUSIONS: The results suggest that deficits in sustained attention are not indicative of a genetic vulnerability to schizophrenia, and are not associated with the occurrence of psychotic symptoms.

Cognitive function and information processing in type 2 diabetes.

AIMS: To determine whether uncomplicated Type 2 diabetes is associated with impairment of cognitive function and information processing ability. METHODS: Thirty-eight participants with uncomplicated Type 2 diabetes and 38 non-diabetic controls were studied. The two groups were comparable for age and premorbid intellectual ability, and did not have other medical disorders likely to affect cognitive function. An extensive battery of tests was administered which assessed different levels and domains of cognitive functions including verbal and visual memory, executive function, general mental ability and efficiency of information processing. RESULTS: No significant differences were found between the diabetic and control groups on any measure of cognitive function or information processing. The performance on these tests was not associated with recent glycaemic control (assessed by HbA1c). Duration of diabetes, however, correlated significantly with poorer performance on several measures of verbal memory. CONCLUSIONS: The results of the present study suggest that some aspect of Type 2 diabetes (as indexed by the estimated duration of the disorder) does relate significantly to cognitive function within the group with diabetes. However, other diabetes-related factors, such as macrovascular disease, hypertension and depression, may contribute more to previously observed cognitive decrements in Type 2 diabetes.

Genetic liability, illicit drug use, life stress and psychotic symptoms: preliminary findings from the Edinburgh study of people at high risk for schizophrenia.

BACKGROUND: Studies of groups at high risk of developing schizophrenia have tended to be based on subjects recruited to the study in their infancy. This paper reports on subjects at genetic high risk for schizophrenia assessed as young adults, close to the age when most onsets of schizophrenia occur. METHODS: One hundred and fifty-five young people at elevated risk for the development of schizophrenia and 36 controls not at increased risk were assessed on entry to the Edinburgh High Risk Study. The measures included current psychotic symptoms, past and present cannabis and other drug use, lifetime life events and two aspects of genetic liability to schizophrenia. RESULTS: Cannabis and other illicit drug use were significantly associated with symptoms in both groups. The same held true for the more upsetting life events experienced, but not for less upsetting ones. Within the high-risk group, there was no relationship between symptoms and a measure of genetic loading, but there was some slight evidence of a higher risk of symptoms when affected relatives were on the father's rather than the mother's side of the family. CONCLUSIONS: Cannabis use, use of other illicit substances and upsetting life events may all lead to psychotic symptoms in vulnerable young people.

Neuropsychological change in young people at high risk for schizophrenia: results from the first two neuropsychological assessments of the Edinburgh High Risk Study.

BACKGROUND: Studies of groups of individuals who have a genetically high risk of developing schizophrenia, have found neuropsychological impairments that highlight likely trait markers of the schizophrenic genotype. This paper describes the change in neuropsychological function and associations with psychiatric state of high risk participants during the first two assessments of the Edinburgh High Risk Study. METHODS: Seventy-eight high risk participants and 22 normal controls, age and sex matched completed two neuropsychological assessments 18 months to 2 years apart. The areas of function assessed include intellectual function, executive function, learning and memory, and verbal ability and language. RESULTS: The high risk participants performed significantly worse on particular tests of verbal memory and executive function over the two assessments than matched controls. Those high risk participants who experienced psychotic symptoms were found to exhibit a decline in IQ and perform worse on tests of verbal memory and executive function than those without symptoms. An increase in psychotic symptoms between the two assessments in the high risk group was found to be associated with an apparent decline in IQ and memory. CONCLUSIONS: The results suggest that the development of psychotic symptoms is preceded by a decline in IQ and memory. This may reflect a general and a more specific disease process respectively.

The effect of sleep fragmentation on cognitive processing using computerized topographic brain mapping.

Topographic brain mapping of evoked potentials can be used to localize abnormalities of cortical function. We evaluated the effect of sleep fragmentation on brain function by measuring the visual P300 waveform using brain mapping. Eight normal subjects (Epworth Score +/- SD: 5 +/- 3) underwent tone-induced sleep fragmentation and undisturbed study nights in a randomized cross-over design. Study nights were followed by topographic brain mapping using a visual information processing test and concurrent event-related potentials. Experimental sleep fragmentation did not significantly increase objective daytime sleepiness or lower cognitive performance on a battery of cognitive function tests (all P > or = 0.1). There were no significant topographical delays in P300 latencies with sleep fragmentation (all P > 0.15). However, at sites Fz, F4, T3, C3, Cz and C4 the P300 amplitudes were reduced significantly after sleep fragmentation (all P < 0.05). A reduction in P300 amplitude has previously been interpreted as a decrease in attention. These reductions in P300 amplitudes with sleep fragmentation in frontal, central and temporal brain areas suggest that sleep fragmentation may cause a broad decrease in attention. Sleep fragmentation did not delay P300 latencies in any brain area, and so does not explain the delay in P300 latencies reported in sleep apnoeics.

Medicare+Choice--cost and funding issues for Medicare risk plans.

The Balanced Budget Act of 1997 contained the most important changes in Medicare since its inception in 1965. The most notable changes include Medicare+Choice, which includes existing Medicare risk programs. The author offers a brief summary of the history of Medicare and the changes that will impact employer/union service providers. Areas of discussion include typical Medicare risk benefit packages, a financial analysis of Medicare risk contractors and changes to risk contracting under the new law.