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Biomedical subjects

C D Frith

Publications and source records attributed to C D Frith.

At least 253 records · Page 14Linked to original sources
PubMed1982

Spontaneous involuntary disorders of movement: their prevalence, severity, and distribution in chronic schizophrenics with and without treatment with neuroleptics.

Using two standardized recording techniques (the Abnormal Involuntary Movement Scale [AIMS] and the Rockland Scale), spontaneous involuntary movement disorder was assessed in a sample of 411 hospitalized patients with chronic schizophrenia, 47 of whom apparently had never been exposed to neuroleptic medication. Prevalence of abnormality clearly depended on the criteria of severity adopted, but overall it was high, with half of the sample on the AIMS and two thirds on the Rockland Scale rating 3 (moderate) or more on one item or more. Comparison of those with a history of treatment with neuroleptics and those with no such history showed few significant differences with regard to prevalence, severity, and distribution of abnormal involuntary movements. We concluded that spontaneous involuntary disorders of movement can be a feature of severe, chronic schizophrenia unmodified by neuroleptic drugs.

Antipsychotic Agents↗
PubMed1982

Skin conductance habituation during acute episodes of schizophrenia: qualitative differences from anxious and depressed patients.

Skin conductance habituation was measured in schizophrenic patients (N = 41) during an acute episode and compared with neurotic patients (N = 86) who were either predominantly anxious or predominantly depressed. All patients were tested before the onset of drug treatment. Between the 14th and 15th tone of the 17 tone simple habituation series a loud 'dishabituating' tone was inserted. In terms of traditional measures based on response frequency, non-habituation was most frequent in the anxious patients and least frequent in the depressed patients, with schizophrenic patients being intermediate. However, in terms of response amplitude the schizophrenic patients showed significantly faster habituation than either neurotic group. This paradox seems to be a consequence of the frequency of spontaneous fluctuations which was highly related to habituation status in the schizophrenic group, but not in the neurotic groups. When habituation was defined in terms of response amplitudes falling below spontaneous fluctuation amplitudes (rather than zero) the schizophrenic group showed the lowest frequency of non-habituation. None of the groups showed any evidence of dishabituation after the loud tone, but the schizophrenics showed a significantly smaller response to the loud tone itself. Following Groves & Thompson (1970), this is interpreted as showing that the loud tone induced a greater response because of its perceived difference from the other tones rather than a sensitization effect because of its loudness. In these terms the schizophrenic patients showed greater response generalization than the neurotic patients.

Acute Disease↗
PubMed1981

The relationships between clinical response, psychophysiological variables and plasma levels of amitriptyline and diazepam in neurotic outpatients.

In a 4 week study of the response of neurotic outpatients to treatment with amitriptyline, diazepam, amitriptyline and diazepam, or placebo clinical and psychophysiological variables and plasma levels of the drug were assessed. Clinical improvements were substantial in all treatment groups but clear relationships between clinical change, psychophysiological change and plasma levels of the drugs were not established. There was no relationship between plasma levels of the drugs and cigarette smoking. It is concluded that neither plasma levels of amitriptyline and diazepam nor change in skin conductance responsivity offer a useful guide to clinical response to drug treatment.

Adult↗
PubMed1981

Alcohol induced discoordination is not reversed by naloxone.

It has previously been reported that prior administration of naloxone may prevent the decrement in performance produced by alcohol. To be clinical value, however, naloxone must be shown to reverse rather than prevent this decrement. This study examined the effect of naloxone given after consumption of alcohol. A double blind balanced crossover protocol was used to examine the effect of either 1.2 mg or 10 mg naloxone on the sensory-motor impairment produced by blood alcohol concentrations maintained between 75 and 85 mg/100 ml. This alcohol concentration significantly impaired two measures of sensory-motor performance, but there was no evidence that either dose of naloxone could reverse this decrement. We tested our subjects for a chlorpropamide alcohol flush but none gave a positive response. These results indicate that naloxone (1.2 mg or 10 mg) does not reverse the sensory-motor impairment produced by alcohol intoxication in subjects who do not exhibit a chlorpropamide alcohol flush. Nearly all the subjects exhibited somnolence after receiving alcohol and naloxone (1.2 mg or 10 mg) but not after receiving alcohol and saline.

Adult↗
PubMed1980

Neurotic illness and its response to anxiolytic and antidepressant treatment.

Two hundred and forty neurotic out-patients were allocated to no diagnostic category but were rated in terms of observer and self ratings of both depression and anxiety at weekly intervals during a 4-week trial of amitriptyline, diazepam, amitriptyline and diazepam, and placebo. The sample could not be divided into anxious and depressed groups on the basis of the clinical picture. The outcome tended to be good irrespective of medication but the significant drug effects found were due to amitriptyline and concerned measures of anxiety as well as depression. It is concluded that a distinction between anxiety and depression in neurotic out-patients is of no practical value with regard to drug treatment.

Adjustment Disorders↗
PubMed1980

Psychoticism and thought disorder in psychiatric patients.

Schizophrenic patients, whether thought-disordered or not, were found to perform worse than other patients when sorting schematic faces, but not when sorting equivalent abstract material. This information-processing deficit was found to be related to self-rated psychoticism scores as well as to factor scores on the factor of schizophrenia derived from the analysis of psychiatrists' ratings of the patients on a large number of symptoms.

Adjustment Disorders↗
PubMed1979

Dopaminergic mechanisms and cognitive deficit in schizophrenia. A neurobiological model.

A hypothesis is briefly discussed proposing that schizophrenic symptoms are due to a breakdown in a mechanism by which conscious attention is limited and directed. It is shown that this mechanism can be modelled in terms of a simple nerve network in which every channel inhibits all the others. Failure of this inhibition would cause the defect hypothesised to occur in schizophrenia. It is shown that if dopamine is given a central role as transmitter in such a network then the various predictions about the biochemistry of schizophrenia that follow are not only consistent with the evidence for the 'dopamine theory' of schizophrenia, but also with much of the evidence held to be contrary to that theory. While not purporting to be an experimentally validated description of schizophrenia, this model goes beyond the single amine theories of schizophrenia and links dysfunctions in amine systems with specific behavioural control mechanisms. Given the current state of knowledge, such models can make only limited predictions about the biochemistry of schizophrenia. However, an attempt to link behavioural and biochemical systems in this way will be crucial for the development of viable animal models of schizophrenia.

Animals↗
PubMed1979

Skin conductance responsivity during acute episodes of schizophrenia as a predictor of symptomatic improvement.

Skin conductance responses to a series of tones were measured in 41 patients during an acute episode of schizophrenia before they received treatment and after 4 weeks of treatment with either alpha-flupenthixol, beta-flupenthixol or placebo. Patients who did not habituate to the tones prior to treatment tended to show no symptomatic improvement during the course of treatment. Patients who habituated and also showed an acute onset of their current symptoms ('Feighner negative' patients) showed a marked improvement even without active medication. Skin conductance responsivity did not change with improvement in symptoms alone, but decreased in patients on active medication (alpha-flupenthixol). Non-habituation of skin conductance and insidious onset (i.e. fulfilment of the Feighner criteria) were found to be independent predictors of poor outcome. Taken together, these criteria may define a group of patients with particularly poor prognosis.

Acute Disease↗
PubMed1979

The outcome of severe acute schizophrenic illnesses after one year.

Forty-five patients with acute schizophrenic illnesses (defined by PSE criteria) were assessed in clinical, cognitive and social terms before being entered in a four week study of the isomers of flupenthixol and placebo. At the end of one year they were re-assessed in the same terms. The clinical and psychological features of the acute illness and the drug treatment given did not predict outcome. Poor outcome in social terms was significantly related to severe social isolation in the initial assessment and to the presence of nuclear symptoms and negative schizophrenic features at follow-up.

Acute Disease↗
PubMed1979

Consciousness, information processing and schizophrenia.

The symptoms of schizophrenia can be interpreted as the result of a defect in the mechanism that controls and limits the contents of consciousness. This defect can be understood as excessive self-awareness. Normally most of the complex information processing which is continuously required by even simple acts of perception, language and thought goes on below the level of awareness; whereas in schizophrenic patients some of this processing, or the results of this processing, not in themselves abnormal, become conscious. This excessive awareness can account for the typical symptoms of schizophrenia and explains many of the specific cognitive abnormalities found in schizophrenic patients.

Cognition Disorders↗
PubMed1978

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Clinical Trials as Topic↗
PubMed1978

Mechanism of the antipsychotic effect in the treatment of acute schizophrenia.

In a double-blind trial in which 45 patients with acute schizophrenia took part the alpha-isomer of flupenthixol (which blocks the dopamine receptor) was found to be significantly more effective than both beta-flupenthixol (which does not) and placebo. The drug effect was confined to the "positive" symptoms--delusions, hallucinations, and though disorder--and appeared only in the 3rd and 4th weeks of the trial. It was as great in patients with evidence of deterioration (Feighner-positive patients) as in patients without deterioration and was less in patients who had affective disturbance in addition to schizophrenia symptoms. The findings are consistent with the hypothesis that dopamine-receptor blockade is the only requirement for antipsychotic activity and suggest that the antipsychotic effect occurs in patients with typically schizophrenic illnesses but may be limited to positive symptoms.

Acute Disease↗