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C Pantelis

Publications and source records attributed to C Pantelis.

69 records · Page 4Linked to original sources
PubMed1996

Cognitive function and duration of rooflessness in entrants to a hostel for homeless men.

BACKGROUND: Four previous studies of homeless adults have yielded conflicting results regarding the presence of cognitive impairment. METHOD: A consecutive series of 80 roofless entrants to a hostel for homeless men were sampled and 62 (76%) completed a range of assessments, including measures of mental state, cognitive functions and substance use. RESULTS: Estimated premorbid IQ (mean = 96), current IQ (mean = 84) and cognitive speed were significantly lower than the norm. There was a significant IQ drop in all diagnostic groups. IQ drop, but not current IQ, correlated with duration of rooflessness. Those with schizophrenia or alcohol problems were roofless for longest. Alcohol misuse did not correlate with IQ drop, excepting alcohol withdrawal symptoms in those with schizophrenia. CONCLUSION: The hypothesis that low IQ is a risk factor for rooflessness is supported. However, length of rooflessness was more closely related to IQ drop than to current IQ, suggesting that some third factor may be affecting both rooflessness and intellectual functioning. Roofless men with schizophrenia or alcohol problems may be especially at risk of long-term rooflessness.

Adult↗
PubMed1996

Drug strategies and treatment-resistant schizophrenia.

OBJECTIVES: The aims of the paper are to review the notion of treatment resistance in schizophrenia and consider the factors important in determining non-responsiveness to standard neuroleptic treatment, and to review the strategies currently available in the treatment of such patients, including an evaluation of recently-introduced, novel drug treatments. METHOD: A selective review of the literature relating to treatment resistance was undertaken using medline searches, followed by cross-checking for further articles identified in these references. RESULTS: The various treatment approaches available are considered, including adjunctive treatment with lithium or carbamazepine. The risks and benefits of high dose antipsychotic treatment are discussed. The possible benefits and side-effects of new treatments, particularly the atypical neuroleptics, are also reviewed. CONCLUSIONS: The reasons why a proportion of patients with schizophrenia fail to respond to standard neuroleptic treatment are ill-understood. Nevertheless, initial assessment should include identification of any factors that may be related to a patient's poor response, such as poor compliance, substance use or epilepsy. This may help to determine an appropriate treatment strategy. There is a need to be systematic and to ensure that patients be given an adequate trial of each treatment tested in terms of duration and dosage. The available evidence does not support the use of high doses of neuroleptics for the majority of patients. Adjunctive treatments, such as lithium, carbamazepine or benzodiazepines may be beneficial in non-responsive patients, particularly if certain target symptoms are present. Atypical neuroleptics, particularly clozapine, have proved particularly effective in non-responsive patients as well as those sensitive to the motor side-effects of standard drugs. However, the high risk of agranulocytosis with clozapine is a problem; also the drug and the necessary haematological monitoring are expensive. There are hints that some of the other, new, atypical neuroleptics have some benefit in non-responsive patients, but controlled studies are required.

Antipsychotic Agents↗
PubMed1996

What have we learned from functional imaging studies in schizophrenia? The role of frontal, striatal and temporal areas.

OBJECTIVES: Functional imaging technologies allow assessment of cerebral blood flow, cerebral metabolism, cellular metabolic processes, cerebral receptor density and occupancy. This review examines the contribution of such studies to our understanding of schizophrenia. The role of the frontal lobes, the basal ganglia, the temporal lobes and the neuronal circuits which connect them is examined with respect to this literature. METHOD: All studies in schizophrenia using positron emission tomography, single photon emission computerised tomography, xenon studies, functional and spectroscopic magnetic resonance imaging formed the basis of this review. Only those studies published in English were reviewed. RESULTS: The most consistent finding in schizophrenia has been that of hypofrontality, while the results of studies examining subcortical structures provide preliminary support for the concept of fronto-striatal dysfunction. Functional imaging has not yet provided consistent results in the study of temporal lobe function. Although receptor studies have shed light on the actions of antipsychotic medications, the findings for dopamine receptor numbers remain controversial. Spectroscopic and functional MRI remain in their infancy as research tools in schizophrenia. CONCLUSIONS: Although there are significant methodological issues to be addressed, functional imaging technology is providing increasing insights into schizophrenia and its treatment. Future research will be truly multidisciplinary as it will require the collaboration of psychiatrists, imaging physicians, neuropsychologists and neuroscientists.

Brain Mapping↗
PubMed1996

A brief assessment of executive control dysfunction: discriminant validity and homogeneity of planning, set shift, and fluency measures.

The current study evaluated the discriminant validity and homogeneity of category fluency, Stroop interference, and planning measures of executive dysfunction and introduced a new measure of planning behavior. We compared performance of patients with schizophrenia, Parkinson's disease, and Huntington's disease, which are disorders associated with some impairment of executive function. Findings indicated that all three measures successfully discriminated between patient groups and controls. Correlational analysis suggested a strong association between test scores on these measures, which were only moderately related to performance on nonexecutive function measures. It is concluded that the three tasks are sensitive and relatively homogeneous in their recruitment of executive functions.

Journal Article↗
PubMed1995

Neuropsychological and olfactory dysfunction in schizophrenia: relationship of frontal syndromes to syndromes of schizophrenia.

Behavioural changes and cognitive impairments in schizophrenia have been linked to disturbances of complex neural networks involving both frontal and subcortical systems. Current literature has emphasised the role of the dorso-lateral prefrontal cortex (DLPFC) and its connections with hippocampus in the pathogenesis of schizophrenia. Based on a review of the literature, this paper examines other possible prefrontal areas that contribute to the manifestations of schizophrenia. We focus on the orbito-frontal cortex (OFC) and argue that it also plays an important role in the behavioural manifestations, symptoms and cognitive impairments observed in schizophrenia. The importance of fronto-striato-thalamic circuits connecting these prefrontal sites with subcortical structures is examined and the relevance of functions specific to these circuits or their components are briefly discussed. The subdivision of the functions of the prefrontal cortex into 'prefrontal' syndromes are examined and related to both the behavioural and symptom-based syndromes of schizophrenia. Possible dissociations of function of the various prefrontal syndromes and the relationship of these to schizophrenia syndromes may provide clues to the underlying neurobiology of schizophrenia. The use of tasks deemed specific to DLPFC and OFC networks may be useful as probes to examine the integrity of these circuits. We discuss such 'circuit-specific' tasks including delayed response, delayed alternation and object alternation tasks derived from the animal literature and other tasks such as olfactory identification ability. This approach raises the possibility that a number of prefrontal cortical areas and their subcortical connections are important in accounting for the heterogeneity of schizophrenia.

Brain Mapping↗
PubMed1995

Cognitive flexibility and complex integration in Parkinson's disease, Huntington's disease, and schizophrenia.

Two new tasks designed to individualize and assess aspects of cognitive flexibility and complex integration were administered to patients with schizophrenia (n = 16), Parkinson's disease (PD; n = 25) and Huntington's disease (HD; n = 12). Findings indicated impaired performance in the schizophrenic and HD groups on components of solution fluency, reactive flexibility and integration. The PD group demonstrated normal performance on all but the solution fluency and reaction time measures. These findings corroborate previous studies suggesting that executive and problem solving disturbances feature in schizophrenia and HD and that these functions may not be as severely affected in medicated PD. Slowed reaction time by both dementia groups is explained with reference to the concept of bradyphrenia.

Adult↗
PubMed1995

Dysfluency in Huntington's disease, Parkinson's disease and schizophrenia.

Verbal fluency was compared in Huntington's disease (n=12), Parkinson's disease (n=25) and schizophrenia (n=18) with a series of fluency tasks evaluating the effects on productivity of cuing with subordinate categories and alternation between fluency probes. Findings indicated reduced output in the patient groups across all tasks consistent with a difficulty in intrinsic generation. A significant group interaction was observed with cue provision, but not with alternation. The facilitation of performance with cuing in all groups suggests a common mechanism of disruption in these disorders, most likely reflecting interruption of the prefrontal modulation of retrieval processes. To explain the observed pattern, we propose that the semantic retrieval anomaly in these disorders reflects a difficulty in intrinsic extra-dimensional shift. Verbal productivity was significantly associated with negative dimensions of schizophrenia, such as poverty of speech and flattened affect, a finding that is discussed in terms of the neurocognitive heterogeneity of schizophrenia and theories of cognitive dysfunction in subtypes of this disorder.

Journal Article↗
PubMed1994

South Westminster schizophrenia survey. Alcohol use and its relationship to symptoms, tardive dyskinesia and illness onset.

In the context of a prevalence survey of schizophrenia in South Westminster, a questionnaire was administered to 271 patients to assess alcohol-related morbidity. In this epidemiologically based sample, the lifetime prevalence of alcohol abuse was 22.1%. Compared with control patients matched for age and sex, these index cases had a significantly shorter duration of illness. A possible explanation is that drinking may mask the onset of schizophrenia, leading to a delay in diagnosis. The index cases also had significantly higher ratings for hallucinations and for hostility, anxiety and depression, and a greater number of disturbed types of behaviour. The highest levels of alcohol consumption were associated with more severe orofacial dyskinesia, suggesting that alcohol use may be an added risk factor for the development of tardive dyskinesia in some patients. The severity of akathisia was also related to alcohol use, and there were significant relationships between the subjective distress related to akathisia and the level of abuse. A possible interpretation is that alcohol had been used by patients with akathisia to alleviate the associated agitation and dysphoria.

Adult↗
PubMed1992

Aerobic exercise in the adjunctive treatment of depression: a randomized controlled trial.

Two clinical trials have been conducted in a sample of depressed patients to determine whether the addition of an aerobic exercise programme to their usual treatment improved outcome after 12 weeks. In the first trial, an aerobic exercise group had a superior outcome compared with a control group in terms of trait anxiety and a standard psychiatric interview. A second trial was then conducted to compare an aerobic exercise programme with low intensity exercise. Both groups showed improvement but there were no significant differences between the groups. In neither trial was there any correlation between the extent of change in the subjects' physical fitness due to aerobic exercise and the extent of the improvement of psychiatric scores.

Adult↗
PubMed1992

Institutionalism and schizophrenia 30 years on. Clinical poverty and the social environment in three British mental hospitals in 1960 compared with a fourth in 1990.

In their comparison of chronic schizophrenic patients in three British mental hospitals in 1960, Wing and Brown found a strong association between the poverty of the social environment and the severity of 'clinical poverty' (blunted affect, poverty of speech, and social withdrawal). Between 1960 and 1968 the social environments of all three hospitals improved and a weak causal relationship between social poverty and clinical poverty was reported in a proportion of patients. Using the same assessment instruments as Wing and Brown, the present study re-examined the relationship between social and clinical poverty in the long-stay schizophrenic population of a fourth British mental hospital in 1990. The association found between social and clinical poverty was much weaker than in 1960. Reluctance on the part of patients to be discharged from the institution was unrelated to length of stay. There was no significant difference in severity of illness between the patients in the present study and those in the earlier study. However, patients in the former group spent more time doing nothing than those in the hospital with the most understimulating environment three decades before, with four-fifths doing nothing for over five hours a day, despite a greatly increased ratio of nurses to patients.

Attitude to Health↗
PubMed1992

Is the concept of frontal-subcortical dementia relevant to schizophrenia?

A syndrome of subcortical dementia has been described in conditions predominantly affecting the basal ganglia or thalamus, structures that have also been implicated in the pathogenesis of schizophrenia. There are similarities between subcortical dementia and the type II syndrome of schizophrenia, in terms of clinical features, pattern of neuropsychological deficits, pathology, biochemistry and data from brain-imaging studies. These similarities raise the possibility that certain schizophrenic symptoms, particularly negative symptoms and disturbance of movement, may reflect subcortical pathology. Neuropsychological deficits of presumed frontal lobe origin have been reported in some schizophrenic subjects. The occurrence of such deficits in a condition in which frontal lobe pathology has not been clearly demonstrated may be explicable in terms of a subcortical deafferentation of the pre-frontal cortex.

Basal Ganglia↗
PubMed1990

Cognitive functioning and symptomatology in chronic schizophrenia.

Chronic schizophrenic patients in a long stay hospital were found to have low levels of intelligence (mean IQ of 80), which was attributed to the effects of substantial intellectual deterioration on below average pre-morbid levels of functioning. Patients with the lowest IQ scores had the least severe positive symptoms but symptomatology was not related to age or extent of intellectual decline. Speed of functioning was relatively more impaired than level of intellectual functioning, with cognitive speed being more affected than motor speed. The severity of negative but not positive symptoms was significantly related to the severity of bradyphrenia (cognitive slowing), a result which would be consistent with the notion of a subcortical pathology in patients with Type II schizophrenia.

Adult↗
PubMed1989

Use and abuse of khat (Catha edulis): a review of the distribution, pharmacology, side effects and a description of psychosis attributed to khat chewing.

There have been relatively few reported cases of psychosis due to khat usage despite its heavy consumption in certain East African and Arabian countries. Four cases have been reported in the UK. We report here on three further cases of psychotic reactions to this substance in Somalian males, and emphasize the need to be aware of khat as a potential substance of abuse, with both medical and psychiatric complications. The features of khat psychoses are described and the relationship to amphetamine and ephedrine psychoses is discussed. The forensic aspects of two of the cases which involved homicide and combined homicide and suicide are highlighted, as is the possible role of social dislocation from the culture of origin.

Adult↗