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Biomedical subjects

M A Roy

Publications and source records attributed to M A Roy.

At least 37 records · Page 2Linked to original sources
PubMed1996

Accuracies and inaccuracies of the family history method: a multivariate approach.

This paper reports on 1459 first-degree relatives of probands with schizophrenia or affective illness and matched community controls. We sought (i) to validate psychiatric diagnoses obtained by family history (FH) against those obtained by a best estimate (BE) procedure based on personal interview and (ii) to explore the factors influencing the accuracy of the FH report. We found relatively poor agreement between the FH and BE diagnoses, and the disagreements were influenced by numerous factors, including gender, psychiatric status of the informant or proband's diagnosis. When validated against a BE diagnosis, the overall accuracy of the FH method is relatively poor, and is furthermore subject to several biases. Therefore, substituting the FH method for BE diagnosis may be an important source of error in the investigation of familial/genetic factors in psychiatric disorders.

Adolescent↗
PubMed1996

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. I: nosology, sex and age of onset.

BACKGROUND: Little is known about the long-term outcome of schizophrenia that has its onset during childhood and early adolescence (early-onset schizophrenia, or EO-SZ). Whether or not EO-SZ is an aetiologically separate form of schizophrenia (SZ) is unresolved. METHOD: The study was a 14.8-year follow-up, using methods such as systematic sampling, evaluation of possible non-respondent bias, consensus best-estimate diagnoses (DSM-III-R) made independently in childhood and adulthood, measures of positive and negative dimensions, of non-psychotic behaviour disturbances (NPBD) and of developmental problems before the appearance of SZ. RESULTS: There was high stability of EO-SZ (n = 40) diagnoses (mean onset at 14.0 years) until adulthood (mean age at follow-up 28.8 years) but a lower stability of positive and negative schizophrenic dimensions. There was a poor outcome of EO-SZ, a strong over-representation of males but few gender differences, and no effect of age of onset on clinical features and outcome. CONCLUSIONS: EO-SZ taken as a whole shows no qualitative differences to adult-onset SZ. However, a distinction through the onset of preschizophrenic developmental problems or NPBD might be a way to investigate heterogeneity within EO-SZ.

Adolescent↗
PubMed1996

Long-term stability of diagnosis and symptom dimensions in a systematic sample of patients with onset of schizophrenia in childhood and early adolescence. II: Postnegative distinction and childhood predictors of adult outcome.

BACKGROUND: The aim of this study was to verify the presence and stability across life of the positive/negative distinction in early-onset schizophrenia (EO-SZ) through a longitudinal factor analysis of the schizophrenic dimensions, and to identify the factors predicting several indices of long-term outcome for EO-SZ. METHOD: Forty children consecutively referred for DSM-III-R schizophrenia (SZ) in a specific catchment area comprised the sample. RESULTS: Across a 14.8-year follow-up, longitudinal factor analysis identified two separate factors corresponding to the positive and negative symptom dimensions. We also observed that: the GAS rated over the last three years of adult illness and the severity of negative symptoms during the stabilised interepisode intervals in adulthood were the indices of adult outcome that were most easily predicted; and the best childhood predictors of adult outcome were premorbid functioning and severity of positive and negative symptoms during acute episodes. CONCLUSIONS: The presence of premorbid non-psychotic behaviour disturbances (NPBD) and premorbid developmental problems was not related to severity of outcome, in contrast to the former variables.

Adolescent↗
PubMed1995

No difference found between winter- and non-winter-born schizophrenic cases.

The distinction between winter-born (WBS) and non-winter born (NWBS) schizophrenic cases has been proposed as a strategy to identify distinct etiologic subtypes within schizophrenia, the WBS subgroup being a predominantly environmental subtype. The goal of this paper is to empirically test the validity of this strategy by comparing WBS and NWBS groups on a broad array of clinical and biological variables. DSM-III-R schizophrenic, schizoaffective and schizophreniform subjects were comprehensively assessed using (i) the Comprehensive Assessment of Symptoms and History; (ii) a comprehensive neurological exam; (iii) a neuropsychological battery, including IQ and the Continuous Performance Test and (iv) an MRI scanning. The patients were divided into WBS and NWBS, using five alternative sets of definitions of winter birth. These comparisons yielded no differences between the groups on any of the 23 variables. The results suggest that the distinction between winter-born and non-winter-born cases has very limited power to identify distinct schizophrenic subtypes, and that better delineation of the correlates of environmental risk factors in schizophrenia will require a better identification of these factors.

Adult↗
PubMed1995

A twin study of generalized anxiety disorder and major depression.

Previous analyses with a sample of female twins sampled from the general population in Virginia have suggested that generalized anxiety disorder (GAD) and major depression (MD) share their genetic determinants but have partly different environmental determinants. The goal of this report is to examine whether these findings apply to samples that include male as well as female twins and contain high proportions of subjects who had been hospitalized for MD. The subjects were ascertained through two different sources: (i) index probands were ascertained through the Swedish Psychiatric Twin Registry for a diagnosis of unipolar or bipolar affective illness; (ii) control twin probands were ascertained through the Swedish Twin Registry. Subjects were sent questionnaires for the assessment of lifetime history of GAD and MD. Positing multinormal distribution of the liability for GAD and MD, we fitted bivariate models to examine the sources of comorbidity. The full model included additive genetic effects, shared environment and individual-specific environment, as well as scalar and non-scalar sex limitations and different thresholds across genders. The best-fitting model included: (i) a genetic correlation of unity; (ii) no common environment; (iii) an individual-specific environmental correlation of 0.28; (iv) different thresholds across genders, but neither scalar nor non-scalar sex-limitations. A model that included additive and dominant genetic effects and individual-specific environment, with correlation of unity for both additive and dominant genetic effects, provided an equivalent fit. These analyses confirm that GAD and MD share the same genetic factors but that their environmental determinants are mostly distinct. Moreover, the present report supports the feasibility of combining clinical ascertained and general-population samples into a single bivariate analysis.

Adult↗
PubMed1995

Negative, psychoticism, and disorganized dimensions in patients with familial schizophrenia or bipolar disorder: continuity and discontinuity between the major psychoses.

OBJECTIVE: This study aimed to answer the following questions: 1) Can we reliably measure the psychopathologic dimensions of schizophrenia by using a lifetime frame and by rating acute and interepisode periods separately? 2) Can we reproduce in subjects with familial schizophrenia the characteristic three-factor structure of schizophrenic symptoms that has been found previously in general groups of schizophrenic patients? 3) Is the factor structure also present in familial bipolar disorder? METHOD: Lifetime measures of psychotic symptoms were taken through a slightly modified version of the Comprehensive Assessment of Symptoms and History for 138 patients with highly familial DSM-III-R schizophrenia (N = 51), bipolar disorder (N = 44), or spectrum disorders (N = 43). Symptoms were rated separately in the acute episodes and in the stabilized interepisode intervals across the patients' lives. RESULTS: A satisfactory level of reliability was obtained. In this highly familial study group, the positive/negative factorial distinction was replicated, as was a three-factor model similar to that observed in prior general groups of schizophrenic patients. These factors were also present in bipolar affective disorder. The negative, psychoticism, and disorganized factor model applied more to the acute phase of illness than to the stabilized state. CONCLUSIONS: These findings offer an empirical basis for testing biological or genetic variables in relation to negative/positive symptom dimensions, rather than diagnoses. Observations of a shared structure for schizophrenia and bipolar disorder suggest some continuity in the causes of these disorders.

Acute Disease↗
PubMed1995

Validity of a diagnosis of lifetime major depression obtained by personal interview versus family history.

OBJECTIVE: Diagnoses obtained by family history agree only modestly with those obtained through personal interview. If personal interview diagnoses are the "gold standard," these findings suggest that family history diagnoses have low validity. Here the authors take another perspective--to evaluate family history versus personal interview diagnoses of lifetime major depression by three independent validators. METHOD: In a large sample of female-female twin pairs and their parents (903 families) ascertained from a population-based twin register, all subjects were personally interviewed by using a modified Structured Clinical Interview for DMS-III-R. Family history diagnoses based on the Family History Research Diagnostic Criteria were obtained by questioning each participant about his or her relatives. By means of multiple regression, the powers of the personal interview and family history methods were compared to predict 1) future episodes of major depression in the twins, 2) neuroticism, and 3) familial aggregation of major depression. RESULTS: Agreement between diagnoses obtained by personal interview and family history was modest. After the presence or absence of a personal interview diagnosis of major depression was controlled for, a family history diagnosis of major depression significantly predicted future episodes of major depression, neuroticism (in five of six analyses), and familial aggregation of major depression (in four of six analyses). CONCLUSIONS: Although agreeing relatively poorly, diagnoses of lifetime major depression obtained by personal interview and family history both contained useful information about future episodes, personality, and familial liability to illness. A multimethod approach to assessment of psychiatric illness may maximize the validity of psychiatric diagnoses.

Adult↗
PubMed1995

The genetic epidemiology of self-esteem.

BACKGROUND: Previous studies on self-esteem have focused exclusively on its psychosocial determinants. The goal of the present study is to clarify genetic v. environmental determinants of self-esteem. METHOD: Participants were Caucasian women sampled from the Virginia Twin Register: 363 pairs of MZ and 238 pairs of DZ twins were available from the first wave of the study, and 430 pairs of MZ and 308 pairs of DZ twins from the second. Self-esteem was assessed with the Rosenberg's Self-Esteem Scale. RESULTS: Using univariate twin analyses of self-esteem and a repeated measurement twin model, we found that self-esteem is a moderately heritable trait (heritability = 52% in the repeated measurement model); environmental influences are also very important, and are probably mostly not shared by members of a twin pair. CONCLUSIONS: Aetiological models of self-esteem which examine only psychosocial factors are incomplete; genetic factors need to be integrated.

Adult↗
PubMed1994

Magnetic resonance imaging in familial versus sporadic cases of schizophrenia.

Magnetic resonance imaging findings were compared in 22 familial and 29 sporadic cases with DSM-III-R diagnoses of schizophrenia, schizoaffective, or schizophreniform disorders. Volumetric measurements were used to assess the size of brain structures, including the cranium, cerebrum, lateral ventricles, temporal horns, third ventricle, lenticular nuclei, amygdaloid-hippocampal complex, and cerebellum, as well as the asymmetry of the lateral ventricles. Increased volume of the lenticular nuclei and greater ventricular asymmetry (the left ventricle being larger) were found in familial cases compared with sporadic cases and normal control subjects. It is possible that increased lenticular nuclei volume and greater lateral ventricular asymmetry reflect the role of genetic factors in schizophrenia.

Adolescent↗
PubMed1994

Biases in the diagnosis of alcoholism by the family history method.

The authors explored the factors influencing the agreement of diagnoses of alcoholism obtained by a best-estimate (BE) procedure versus those obtained by family history (FH) only, based on data from the Roscommon Family Study. The participants were first-degree relatives of either schizophrenic subjects, subjects with affective disorders, or matched community controls. The FH information was obtained from first-degree relatives of the participants, whereas the BE diagnoses included personal interview and medical records as well as FH information. Two types of error were distinguished: false-negative FHs, who were diagnosed with alcoholism by BE but not by FH; and false-positive FHs, who were diagnosed with alcoholism by FH but not by BE. The risk of false-negative FHs was increased by young age of the subject and male gender of the informant, and decreased by a history of previous hospitalization of the subject. Conversely, the risk for false-positive FHs was increased by older age of the subject, male gender of the subject, female gender of the informant, and informant's diagnosis of alcoholism. Comorbid diagnosis of nonaffective psychosis increased the risk of both types of error. It is concluded that when validated against a BE diagnosis, the FH diagnosis of alcoholism is subject to several biases and that the FH method is not a satisfactory substitute for BE diagnoses.

Adolescent↗
PubMed1994

Epidemiological and clinical correlates of familial and sporadic schizophrenia.

We studied 68 schizophrenic cases with a schizophrenic first-degree relative (familial group) and 62 cases without such a family history (sporadic group). We compared them on: (i) clinical variables, including premorbid adjustment, age of onset and severity of symptoms; (ii) neural abnormalities, including abnormal involuntary movements, neural "soft" and "hard signs"; (iii) neuropsychological tests, including the Wechsler Adult Intelligence Scale and the Continuous Performance Test and (iv) environmental risk factors, including winter birth and obstetrical complications. Sporadic cases were more likely to be born in winter and had more severe psychotic symptoms, but most analyses yielded no difference between the groups. Our results offer some support that sporadic schizophrenia is a more environmental subtype, but they also suggest that the familial vs sporadic distinction of schizophrenia has limited power to identify distinct subgroups.

Adaptation, Psychological↗
PubMed1994

Validity of the familial and sporadic subtypes of schizophrenia.

OBJECTIVE: A common means of subtyping schizophrenia is to use family history. Familial schizophrenia is defined by a family history of psychotic disorders, and sporadic schizophrenia is defined by the absence of such a history. Some writers have proposed that familial cases are mostly genetic, while the causes of sporadic schizophrenia are primarily environmental. The object of this report is to consider the theoretical and empirical support for the validity of this classification. METHOD: A review of studies examining the familial-sporadic distinction in schizophrenia was based on papers located through a MEDLINE search and published bibliographies. Because of the great variation in the methodological rigor of the studies, the authors rated them on a scale assessing 10 methodological features. Studies achieving at least 50% of the maximum possible score were selected for review. RESULTS: Only 29 of 69 studies located met the selection criteria, and even among the studies selected, important methodological shortcomings were noted. Despite an impressive number of comparisons between groups of subjects with familial and sporadic schizophrenia, few differences were found. In addition, few differences were replicated and supported by studies using designs other than the familial-sporadic distinction. CONCLUSIONS: The scarcity of studies with adequate methodology precludes any definitive judgment about the validity of the familial-sporadic distinction in schizophrenia. The delineation of predominantly genetic and predominantly environmental subtypes of schizophrenia will likely require large sample sizes, valid methods for the diagnosis of relatives, and stringent definitions of familiarity and sporadicity. Moreover, research strategies other than the familial-sporadic distinction may be better suited to identify such subtypes.

Adult↗
PubMed1994

[Positive and negative symptoms in schizophrenia: a current overview].

The purpose of this article is to summarize the results of studies examining the validity of the positive and negative sub-types of schizophrenia as proposed by Crow. The authors summarized Crow's model's predictions in the form of 12 research questions and examined whether its predictions were confirmed. The following predictions are generally confirmed by the data collected: (i) it is possible to measure negative symptoms with accuracy; (ii) the negative symptoms predict a deterioration; (iii) the negative symptoms are generally correlated with overall cognitive deficits; (iv) each dimension appears to have distinct neurobiological substrata. However, several elements of the Crow model are not supported by the data collected. Among the necessary modifications, the most important are as follows: (i) it appears more productive to conceive of the negative symptoms as distinct dimensions, rather than distinct diseases; (ii) at least three dimensions exist for describing the symptoms of schizophrenia; (iii) the negative symptoms are not necessarily intrinsic to the schizophrenic process, and they may be due to other causes; (iv) the negative symptoms are not necessarily irreversible, and can be improved under ataractics; (v) the positive symptoms, in particular those relating to disorganization, can also be correlated with cognitive deficits.

Antipsychotic Agents↗
PubMed1992

Reliability of best-estimate diagnosis in genetic linkage studies of major psychoses: results from the Quebec pedigree studies.

OBJECTIVE: Diagnostic classification and reliability are critical in genetic linkage studies of schizophrenia and bipolar disorder. To establish an optimal diagnostic procedure, the authors drew 13 methodological elements from 38 major linkage studies and workshop reports. They determined reliability for a consensus best-estimate diagnostic method based on these 13 features. METHOD: Each of 59 subjects from several large multiplex pedigrees, densely affected by either schizophrenia or bipolar disorder, received a best-estimate diagnosis from unblind diagnosticians in the field and also from a panel of four research psychiatrists who were blind to the proband's and relatives' clinical status. The best estimate was based on personal diagnostic interviews, all available medical records, and family history data. RESULTS: The diagnostic concordance between the field team and the blind psychiatric board yielded 78% to 90% agreement for the whole sample (kappa = 0.83-0.88) and 71% to 87% agreement for the subjects given field diagnoses (kappa = 0.76-0.83). The diagnoses made by the unblind field diagnosticians were biased toward a greater severity (or certainty) level in the diagnostic hierarchy (schizophrenic or bipolar) and more consistency with the most prevalent diagnosis affecting the pedigree. CONCLUSION: Since several previous linkage studies used diagnoses made by diagnosticians who were not blind to the status of the probands and the relatives or did not use a consensus best-estimate diagnosis, further reliability studies of different aspects of the best-estimate method and of its effect on linkage studies are needed. Such research is imperative given the serious impact of diagnostic misclassifications on genetic linkage results.

Adolescent↗
PubMed1992

Prevention of primary cutaneous malignant melanoma: increasing cure rate in the 1990's.

This review focuses on the epidemiology, risk factors, early detection, and metastatic risk of thin primary cutaneous malignant melanoma. Primary prevention strategies and the results of screening programs and public education campaigns are discussed. Recent advances in the development of noninvasive diagnostic devices for primary cutaneous malignant melanoma are summarized.

Female↗
PubMed1990

Proprioceptive facilitation of muscle tension during unilateral and bilateral knee extension.

The effects of double neuromuscular facilitation (DNF) in unilateral movements and of quadruple neuromuscular facilitation (QNF) in bilateral movements were studied in 42 physically active college-age male subjects. Results showed a 10.4% significant increase of maximal knee extension torque output when unilateral extension was preceded by a knee flexion on an isokinetic exerciser and a 16.7% increase of maximal torque in the bilateral condition of simultaneous alternating flexion-extension when compared to the simultaneous extension movement. Consequently, the increased peak torque observed in the unilateral and bilateral experimental conditions in which knee extension was preceded by a knee flexion appears to be the result of a combination of neuromuscular influences and stored elastic energy.

Adult↗