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Query: UMLS:C0036341 (schizophrenia)
 60,220 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Confusion may exist between the reliability of a binary rating (for example, schizophrenia versus not-schizophrenia) and its implications for validity. High reliability does not guarantee validity, but paradoxically, low reliability does not imply poor validity in all contexts. Changes in the base rate or in experimental design may indicate high validity even when the reliability was thought to be low. Attempts to improve the psychiatric nomenclature by increasing only reliability run the risk of the "attenuation paradox" where further increases in reliability will make the ratings less valid. Finally, the assumption of random error in making diagnoses does not always hold, so that statistical analyses must be adjusted accordingly. New statistical methods are needed to index only false-positive or false-negative rates in order to quantify the error that will reduce some validity coefficients.
Arch Gen Psychiatry 1978 Dec
PMID:Reliability and validity in binary ratings: areas of common misunderstanding in diagnosis and symptom ratings. 72 82

The present study investigates the ability of chronic schizophrenic patients to learn to obtain social rewards when the incentive value of the contingent social event is known. From a group of 40 chronic patients tested for responsivity to social rewards, socially responsive and socially unresponsive patients were selected and compared on a learning task. Patients who were highly motivated to obtain social reinforcement did not emit the reinforced response during 300 learning trials any more frequently than did patients who were not motivated by social rewards. It was only when the experimental contingency was specified that responsive and unresponsive patients could be differentiated. The implications of these findings for social motivation theories of schizophrenia are discussed.
Br J Med Psychol 1978 Dec
PMID:Contingency learning in chronic schizophrenia and its relevance to social motivation deficit. 73 47

Platelet monoamine oxidase (MAO) activity was measured in patients with nonaffective schizophrenic disorders (i.e., without prominent symptoms of depressions or manias), and in patients with schizophrenia-related depressions. MAO activity was significantly lower than control values in a subgroup of 16 patients with nonaffective schizophrenic disorders (most of whom were paranoid) characterized by the presence of auditory hallucinations and delusions. Platelet MAO activity was not reduced in 16 other nonaffective schizophrenic patients without auditory hallucinations. Platelet MAO activity was significantly higher than control values in a group of 8 depressed patients with schizophrenia-related depressions characterized by the presence of chronic asocial, eccentric, or bizarre behavior. These findings of differences in platelet MAO activity in clinically defined subgroups of nonaffective schizophrenic disorders and the schizophrenia-related depressive disorders may help to account for some of the discrepancies in findings among the various studies of platelet MAO activity in schizophrenic and affective disorders.
Biol Psychiatry 1978 Dec
PMID:Differences in platelet monoamine oxidase activity in subgroups of schizophrenic and depressive disorders. 73 52

Previous work has indicated that abnormal methylation processes may be associated with schizophrenia. In this study, leukocytes from patients with schizophrenia were incubated with methyl-14C-L-methionine and the evolved 14CO2 measured. With increasing concentration of methionine, the evolved 14CO2 was lower in the patients than in normal control subjects. The incorporation of 14C into protein was the same in both groups, and when carboxyl-14C-L-methionine was used the evolved 14CO2 was the same in both groups, thus excluding the possibility that altered incorporation into protein or oxidation of the methionine molecule as a whole were responsible. The observed differences in methionine-methyl metabolism suggest that an abnormality in transmethylation processes or in oxidation of the methyl group to CO2 is associated with schizophrenia. That this occurs in a peripheral tissue indicates that the abnormality is not restricted to the central nervous system.
Biol Psychiatry 1978 Dec
PMID:Altered metabolism of the methionine methyl group in the leukocytes of patients with schizophrenia. 73 53

The activity of dopamine-beta-hydroxylase (DBH) in cerebrospinal fluid (CSF) from 59 psychiatric patients has been analyzed by a highly sensitive radio-enzymatic assay. There was no sex difference in DBH, but there was a significant positive correlation with age. Probenecid administration had no effect on CSF DBH. DBH in CSF correlated positively (r = 0.60) with the plasma enzyme. Among patients hospitalized for major depressive disorder, unipolar or bipolar, schizo-affective disorder, schizophrenia, alcoholism, or personality disorders there were no significant between-group differences. Among the patients with bipolar affective disorder, DBH activity from manic patients was significantly lower than that from depressed or euthymic patients. The results are discussed with reference to the theory that the amount of DBH in CSF may serve as an indicator of central noradrenergic activity.
Biol Psychiatry 1978 Dec
PMID:Dopamine-beta-hydroxylase in the cerebrospinal fluid of psychiatric patients. 73 56

A systematic sample of 200 Sudanese individuals (100 males and 100 females) attending 4 health centres (2 urban and 2 rural) were interviewed, using standardized vignettes and a structured questionnaire, to explore their attitudes to mental illness and the mentally ill people. Information obtained from 183 (91.5%) of the respondents was analysed. Serious mental illness, represented by schizophrenia, was recognized as such by 76 per cent of both the urban and rural population and psychiatric treatment was suggested for it by more than half of them. About one-third of the respondents though of depression as just over-worry. The least recognition, as mental illness, was for alcoholism especially in the rural areas. More rural people than urban opted for religious healing as a method of treatment. Religious factors and people's concept of mental illness seem to influence their tolerance of deviant behaviour.
J Trop Med Hyg 1978 Dec
PMID:Attitudes of Sudanese urban and rural population to mental illness. 74 70

The finding, in the following study, of grandparent death within +/- two years of birth of 41 per cent of schizophrenics (N = 70), a rate significantly higher than that in psychiatric (N = 45) and normal (N = 25) control groups, raises the possibility that this family stress factor may contribute to the development of schizophrenia. The implications are considered regarding the likelihood that the concurrent stresses of the death and the birth, two major events in the family life cycle, could confound and impede mourning and parenting processes. Two hypotheses are suggested: (a) that a bereaved parent may be emotionally unavailable to spouse and infant, and (b) that attention to the child may block mourning and absorb painful feelings, with the child assuming a special replacement role. The dysfunctional potential is related to other interacting variables, including biological factors, mourning resolution, and the family system. Further study is called for.
Fam Process 1978 Dec
PMID:Concurrent grandparent death and birth of schizophrenic offspring: an intriguing finding. 75 15

Among the evidence supporting the dopamine hypothesis of schizophrenia is the finding that both amphetamine and methylphenidate hydrochloride, potent releasers of dopamine, can cause exacerbation of symptoms in the acute schizophrenic patient. The present report describes three experiments in which the effects of amphetamine in chronic schizophrenic patients were studied. In one of the experiments, orally administered, daily doses of 20 mg of dextroamphetamine sulfate given at 8 PM had little or no effect on the sleep duration of the subjects. In the other two experiments, doses up to 40 mg given orally also had little or no effect on the performance of the subjects on a variety of behavioral tests. There was no evidence of an exacerbation of the disease process in any of the subjects. The most consistent amphetamine effect was a dose-related increase in blood pressure. These results indicate that the chronic schizophrenic patient may be hyporesponsive to amphetamine and suggest that if the dopamine hypothesis is correct, then it must be modified to take into account these findings in the chronic patient.
Arch Gen Psychiatry 1976 Dec
PMID:Hyporesponsivity of chronic schizophrenic patients to dextroamphetamine. 79 62

To improve observer uniformity and objectivity in the psychiatric appraisal of parents of psychotic children, structured psychiatric interviews were administered to 64 parents of psychotic children, including 28 husband--wife pairs and 8 single parents. Judgments were recorded on the Spitzer--Endicott Psychiatric Status Schedule and the past section of their Current and Past Psychopathology Scales. There were no significant differences between fathers and mothers of organic and nonorganic children (children with and without evidence of neurological dysfunction). As a whole, the 56 parents in the 28 participating husband-wife pairs fell between a contrast group of 55 adult subjects attending a psychiatric clinic and another contrast group of 130 subjects living in the community in upper Manhattan in their trends to pathological symptoms as judged by the Psychiatric Status Schedule. Similarly, in the past section of the Current and Past Psychopathology Scales the parents showed a trend to more psychopathology than a community sample of 36 nonpatient adults. Finally, computer diagnoses based on the Psychiatric Status Schedule showed more schizophrenia in the parents of the psychotic children than in a sample of 130 nonpatient adults in the community. The data thus tend to support findings based on the unstructured interview of elevated schizophrenia rates in parents of psychotic children.
J Autism Child Schizophr 1976 Dec
PMID:A study of psychopathology of parents of psychotic children by structured interview. 79 50

A census in a London mental hospital was performed so that the numbers of patients requiring permanent care for the next 20 to 40 years could be estimated. Of 1467 resident patients 20% had been admitted in the preceding five months and 15% in the year before that. Of the 65% who had been in hospital for over 17 months 1% (16 patients) had been in hospital for over 5o years. Altogether 257 (18%) patients would probably be discharged, 339 (23%) might possibly be discharged if there were adequate community facilities, but 871 (59%) were not likely to be discharged; 239 patients under the age of 65 who had been admitted between 1950 and 1973 were unlikely to be discharged. There were about 10 new younger long-stay patients from each year's admissions. Three conditions--schizophrenia, organic brain syndrome, and affective illness--affected 79% of the population. Fourteen per cent had been employed on admission and 28% were considered employable or possibly employable. Half of those who might be considered for discharge (296) would need a hostel. No rehabilitation was needed or possible for 40% of the patients; 299 (20%) patients were chairbound or bedridden and 400 (27%) were totally dependent on nursing and 587 (40%) partly dependent. Twenty months after the census 361 (25%) patients had left (59 had been readmitted), 284 (19%) had died, and 822 (56%) had remained as inpatients. The most realistic future prediction was that 210 (14%) of these patients would still be in the hospital in 20 years and 43 (3%) in 40 years. In the light of these findings and the scarceness of resources current Department of Health and Social Security plans for phasing out mental hospitals must be challenged.
Br Med J 1975 Dec 20
PMID:Census of mental hospital patients and life expectancy of those unlikely to be discharged. 81 84


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