Search PubMed⌕ Search

Biomedical subjects

A Y Tien

Publications and source records attributed to A Y Tien.

36 records · Page 2Linked to original sources
PubMed1995

Structural differences in the cerebral cortex of healthy female and male subjects: a magnetic resonance imaging study.

There are both reproductive and nonreproductive behavioral differences between men and women. Brain regions involved in determining sexual behavior have been reported to differ between the sexes. Nonreproductive, cognitive functional differences between sexes might be reflected in higher-order cortical structural dimorphisms, which have not previously been studied. We hypothesized that cortical regions involved in verbal behavior (which is sexually dimorphic) would differ between sexes. Using magnetic resonance imaging, we assessed gray matter volumes in several cortical regions in 17 women and 43 men. Women had 23.2% (dorsolateral prefrontal cortex) and 12.8% (superior temporal gyrus) greater gray matter percentages (corrected for overall brain size and age) than men in a language-related cortical region, but not in a more visuospatially related cortical region. These data seem to establish sexually dimorphic structural differences in the cerebral cortex, consistent with prior cerebral blood flow reports.

Adult↗
PubMed1995

Posterior superior temporal gyrus in schizophrenia: grey matter changes and clinical correlates.

We report an MRI morphometric study of the posterior segment of the superior temporal gyrus (STG) in twenty young male schizophrenics and their individually matched normal controls. In particular the more posterior segment of STG was examined, since it has been identified as the approximate site of Wernicke's language area and is a marker for the planum temporale, a region believed to be abnormal in schizophrenia. Total volumes and grey and white matter volumes were measured in middle and posterior STG in each hemisphere. STG grey matter volumes and percentages were significantly reduced bilaterally in both regions in schizophrenic subjects. No significant differences between patients and controls were noted in STG white matter volumes. A significant correlation was detected between delusion scores in schizophrenics and the total volume of the left dominant posterior STG. Replicating the findings of a recent study (Shenton et al., 1992), we found an inverse correlation between thought disorder scores and grey matter reduction in the left posterior STG in schizophrenia.

Adult↗
PubMed1995

Reversal of asymmetry of the planum temporale in schizophrenia.

OBJECTIVE: The planum temporale is intimately involved in the generation and understanding of language and has been suggested to be a key area affected in schizophrenia. To explore temporal lobe abnormalities in schizophrenia, the authors measured the planum temporale, a normally asymmetric area lying on the superior part of the temporal lobe, in schizophrenic patients. METHOD: High-resolution magnetic resonance imaging (MRI) scans were obtained for 14 right-handed schizophrenic patients and 14 healthy comparison subjects individually matched for age, sex, handedness, race, and parental socioeconomic status. The surface area of the planum temporale was measured by using MRI reconstruction techniques. RESULTS: There was striking reversal of the normal asymmetry (left larger than right) in planum temporale surface area in 13 of the schizophrenic patients but in only two of the comparison subjects. However, Heschl's gyrus (primary sensory cortex), which served as an anatomically contiguous nonheteromodal cortical comparison region, showed no difference between the left and right sides in either group. Severity of thought disorder in the patients was related to asymmetry. CONCLUSIONS: This is a clear demonstration of a reversal of expected symmetry in the brains of right-handed schizophrenic patients, which involves a region of key importance in normal human behavior. The nature of the abnormality strongly suggests that schizophrenia is a neurodevelopmental disorder.

Adult↗
PubMed1995

Magnetic resonance imaging measurement of gray matter volume reductions in HIV dementia.

OBJECTIVE: The authors recently reported smaller basal ganglia volumes for patients with HIV-associated dementia than for HIV-infected patients without dementia and a seronegative comparison group. The purpose of the current study was to determine whether HIV dementia is associated with volume reductions in other brain regions. METHOD: The authors measured volumes of CSF and gray and white tissue on cranial magnetic resonance images from homosexual men who were 1) infected with HIV with HIV-associated dementia complex, 2) infected with HIV without dementia, and 3) HIV seronegative. RESULTS: Results suggest that loss of white matter occurs with HIV infection and is more severe in HIV-positive patients with dementia than in those without dementia. There was some generalized volume reduction in gray matter in HIV-positive demented patients, although group differences did not reach significance when adjusted for age. Volume of posterior cortex, however, was significantly smaller among HIV-positive patients with dementia than in either remaining group. There were no significant differences between HIV-positive nondemented patients and HIV-negative subjects in these regions. CONCLUSIONS: In conjunction with findings from previous research, the authors conclude that HIV dementia is associated with specific gray matter volume reduction in basal ganglia and posterior cortex, as well as with generalized volume reduction of white matter.

AIDS Dementia Complex↗
PubMed1994

Risk factors for the incidence of social phobia as determined by the Diagnostic Interview Schedule in a population-based study.

The Diagnostic Interview Schedule was used to identify 89 incident social phobia cases in wave 2 household subjects from 9437 at risk persons age 18 or older as part of the Epidemiologic Catchment Area study. Crude annual incidence of Diagnostic Interview Schedule/DSM-III social phobia was estimated at 9 per 1000 population per year. Onset of social phobia was associated with low education, never having been married and female gender. First onsets occurred throughout the life course of this adult sample. Nervousness, headache, panic spells, palpitations, other phobias, binge pattern of alcohol consumption, dysthymia and schizophrenic symptoms were also predictive of social phobia onset. There was no difference in predictive factors when "primary" social phobia (without premorbid panic) was analyzed separately.

Adolescent↗
PubMed1994

Decreased regional cortical gray matter volume in schizophrenia.

OBJECTIVE: The authors hypothesized that cortical gray matter volume reduction in schizophrenia is greatest in the heteromodal association cortex. This area comprises a highly integrated, reciprocally interconnected system that coordinates higher order cortical functions. METHOD: Total brain and regional gray matter volumes were calculated in 46 schizophrenic patients and 60 age and sex-matched comparison subjects by using magnetic resonance images. Disease specificity was examined by assessing 27 patients with bipolar disorder. Approximations to the dorsolateral prefrontal cortex, inferior parietal lobule, and superior temporal gyrus were selected as regions of interest for the heteromodal association cortex. Occipital and sensorimotor areas were used as comparison regions to test the hypothesis for regional specificity. RESULTS: Gray matter volume was reduced in schizophrenic patients in index regions even after covariance for overall brain volume, sex, and age. Bipolar disorder patients did not exhibit heteromodal gray matter reduction. Comparison regions did not differ among the three groups. Global gray matter volume was not different among groups after covariance for global brain volume. Comprehensive individual region post hoc analysis found no additional gray matter differences. CONCLUSIONS: These findings support the theory of disproportionate reduction of gray matter volume in the heteromodal association cortex specific to schizophrenia.

Adult↗
PubMed1993

Quantitative D2 dopamine receptor PET and structural MRI changes in late-onset schizophrenia.

Late-onset schizophrenia (LOS) is likely a syndrome of diverse etiology. In a series of related studies, we compared LOS patients with normal controls, elderly patients with early-onset schizophrenia (EOS), and Alzheimer's disease patients, using magnetic resonance imaging (MRI) and neuroreceptor positron emission tomography measures, which had previously been reported to be abnormal in EOS. EOS and LOS patients showed similar MRI changes. LOS drug-naive patients had elevated Bmax (receptor density) values for dopamine D2 receptors compared with age and gender norms, a phenomenon previously reported by our group in young schizophrenia patients.

Aged↗
PubMed1992

Psychopathologic precursors and sociodemographic risk factors for the schizophrenia syndrome.

This article presents a prospective analysis of an antecedent psychopathologic features and sociodemographic risk factors in schizophrenia with data from five community sites in the National Institute of Mental Health Epidemiologic Catchment Area Program. Three nonoverlapping psychotic cases were defined using DSM-III definitions as implemented by the Diagnostic Interview Schedule (DIS): (1) DSM-III Schizophrenia Criterion A; (2) Criterion A and Affective Episode; and (3) full Schizophrenia. In a 1-year follow-up period, the cumulative incidence rate of Criterion A was 0.79 per 100, for Criterion A with Affective Episode it was 0.17 per 100, and for Schizophrenia the rate was 0.20 per 100. In multivariable logistic regression modeling, the patterns of associations between sociodemographic factors and DIS/DSM-III Schizophrenia resembled patterns in clinically based registry data. Male subjects had an earlier peak onset than female subjects, and marital status and employment were strongly related to odds of developing DIS/DSM-III Schizophrenia. An interaction between gender and never marrying showed never-married men at 50 times higher odds of developing DIS/DSM-III Schizophrenia, never-married women at 14 times higher odds, and married women at 2.5 times higher odds, relative to married men. Adjusting for sociodemographic factors, DIS/DSM-III Obsessive Compulsive Disorder and Social Phobia were both associated with more than 3.5 times increased odds of developing DIS/DSM-III Schizophrenia. Several other psychopathology items, including panic attacks, were associated with increased odds of developing DIS/DSM-III Schizophrenia. There were both similarities and differences in risk factor structure between DIS/DSM-III Schizophrenia and the other two defined categories of case.

Age Factors↗
PubMed1992

Covariance of personality, neurocognition, and schizophrenia spectrum traits in the community.

Clinical researchers have observed in relatives of schizophrenic individuals abnormal personality traits resembling the psychopathology of schizophrenia. Further similarities have been observed in correlations between measures of brain function, including attention and executive abilities, and these personality psychopathologies. However, two methodologic factors might account for the covariation of these 'schizophrenia spectrum' personality traits and measures of brain function. Clinical selection bias (Berkson's bias) might result in subjects with overlapping conditions being more likely to be studied, and normal personality attributes could affect performance on neurobehavioral tasks. This study investigated relationships between neurobehavioral correlates of schizophrenia, clinical schizophrenia spectrum personality traits, and normal personality dimensions in the five-factor model of personality. To avoid Berkson's bias, subjects expected to have a high probability of spectrum traits were recruited from the Baltimore Epidemiologic Catchment Area Survey community sample. About 40% of the sample were found to have DSM-IIIR Schizotypal, Schizoid, or Paranoid Personality Traits or Disorders. Schizophrenia Spectrum traits showed significant associations with personality dimensions of the five factor model, particularly Openness to Experience and Neuroticism. In ordinary linear regression models, after adjustment for a number of normal personality characteristics, Schizotypal Personality Traits were still strongly associated with perseverative responses on the Wisconsin Card Sorting Test (WCST). In logistic regression models, subjects with Schizotypal, Schizoid, or Paranoid Traits differed in terms of normal personality profiles and WCST performance.

Adult↗
PubMed1992

Oculomotor performance in obsessive-compulsive disorder.

OBJECTIVE: Neuroimaging studies have shown abnormalities of the frontal cortex and basal ganglia in persons with obsessive-compulsive disorder. Since lesions in the frontal cortex and basal ganglia areas affect performance on goal-guided saccadic eye movements, this study investigated the relation between the diagnosis of obsessive-compulsive disorder and oculomotor performance. METHOD: Eleven patients with the clinical diagnosis of obsessive-compulsive disorder and 14 normal subjects were assessed with respect to their performance on both visual-guided and goal-guided oculomotor tasks. Fixation performance was also measured. RESULTS: The group with obsessive-compulsive disorder had a very significantly greater error rate and a significantly greater rate of inaccurate saccades on the goal-guided antisaccade task, whereas they were not different from the normal group in reaction time, saccadic velocity, and accuracy on the visual-guided saccade task. The distribution of error rates for the patients with obsessive-compulsive disorder was broad, with more than one-half outside the range of the normal group. Most of the abnormal findings were among male patients. CONCLUSIONS: The results support the hypothesis of a relationship between impaired performance on goal-guided saccadic eye movement tasks and the diagnosis of obsessive-compulsive disorder, but they also suggest a gender-related subgroup within the group with obsessive-compulsive disorder.

Basal Ganglia↗
PubMed1991

Occupational characteristics and the occurrence of psychotic disorders.

This study was undertaken to investigate whether individuals working under various occupational stressors are at increased risk of three forms of psychotic conditions. This paper presents prospective analyses of antecedent occupational stressors in psychotic conditions with interview data from a community sample in five US metropolitan areas--the NIMH Epidemiologic Catchment Area Program. Three non-overlapping conditions were defined using DSM-III definitions as assessed by the Diagnostic Interview Schedule (DIS): (1) DSM-III schizophrenia criterion A; (2) full schizophrenia; and (3) criterion A and affective episode. Artistic (RR = 3.32, 95% CI 1.08-10.14) and construction trades occupations (RR = 2.58, 95% CI 1.15-5.77), "noisome working conditions" occupations (RR = 1.20, 95% CI 0.99-1.47) and physically demanding occupations (RR = 1.39, 95% CI 1.05-1.72) were associated with increased risk of developing DIS/DSM-III schizophrenia criterion A, even after adjustment for sociodemographic and psychopathology factors including alcohol and marijuana use. Psychologically demanding occupations (RR = 0.85, 95% CI 0.75-0.95) were associated with decreased risk of developing DIS/DSM-III schizophrenia. This finding is supported by results from experimental studies on the arousability of pre-schizophrenics. Finally, teachers (RR = 11.35, 95% CI 2.56-50.38), sales occupations (RR = 4.16, 95% CI 1.00-21.30) and occupations characterized by low control over work were associated with increased risk of developing DIS criterion A and affective episode, resembling previous findings on occupational stressors and depression. Overall, our results replicate and extend previous work on occupational stressors and psychotic conditions through use of prospective data, several psychotic conditions, multiple assessment of occupational stressors and adjustment for potential confounders.

Adolescent↗
PubMed1991

Distributions of hallucinations in the population.

Hallucinations are often manifestations of severe psychiatric conditions seen clinically. However, little is known about the distribution of incident hallucinations in the community, nor whether there has been a change over the past century. Data from the NIMH Epidemiologic Catchment Area Program is used here to provide descriptive information on the community distribution, and data from the Sidgewick study from a century earlier provides comparative information. In the ECA data, the incidence of visual hallucinations was slightly higher in males (about 20 per 1000 per year) than females (about 13 per 1000 per year) across the age span from 18 to 80 years old, with a subsequent increase in the rate for females (up to about 40 per 1000 per year) after age 80. For auditory hallucinations there was an age 25-30 peak in males with a trough for females, and a later age 40-50 peak for females. Overall, there were substantial gender differences, and the effect of aging to increase the incidence of hallucinations was the most consistent and prominent. The Sidgewick study showed a much higher proportion of visual hallucinations than the ECA program. This might be due to factors affecting brain function as well as social and psychological changes over time, although methodological weaknesses in both studies might also be responsible.

Adolescent↗
PubMed1991

Disengagement of attention in schizophrenia.

We compared covert shift of visual attention in patients with schizophrenia or bipolar disorder, both in states of remission, to normal controls to examine the persistence of lateralized attentional deficits into nonpsychotic states. Although patients were slower in all conditions than normals, there was no difference in pattern of attentional shift among the groups. This suggests that the left-hemisphere deficit in shift of covert attention in schizophrenia may be limited to periods of florid illness.

Attention↗
PubMed1990

Epidemiological analysis of alcohol and drug use as risk factors for psychotic experiences.

Clinical and laboratory studies link alcohol and other drug use to the occurrence of psychotic experiences, but epidemiologic evidence has been lacking. In this study, the quantitative relationships between alcohol or other drug use and psychotic experiences were examined by analysis of prospective data from 4994 adult household residents sampled in a multisite survey of mental disorders in the population, the NIMH Epidemiologic Catchment Area Program. After control for sociodemographic factors and preexisting psychiatric conditions, the risk for onset of self-reported delusions or hallucinations was observed to be greater for daily users of marijuana or cocaine and for users of anxiolytics or sympathomimetics compared with nonusers. After control for daily cocaine use and alcohol disorder, the risk of onset of psychotic experiences for daily users of marijuana was double that for nonusers. Alcohol disorder in men was associated with eightfold risk and in women with threefold risk. Baseline depressive episodes, manic episodes, agoraphobia, and obsessive-compulsive disorder also were associated with increased risk of onset of psychotic experiences.

Alcoholism↗
PubMed1989

Epidemiologic evidence on cocaine use and panic attacks.

Experienced drug takers and clinicians report that cocaine causes panic attacks. This claim is supported by laboratory evidence on the pharmacologic activity of the drug. In this paper, the authors have used an epidemiologic strategy to examine the suspected cocaine-panic association, with interview data from 5,896 adult household residents sampled in the early 1980s and followed prospectively for a collaborative multisite study of mental disorders in five US metropolitan areas: New Haven, Connecticut; Baltimore, Maryland; St. Louis, Missouri; Durham, North Carolina; and Los Angeles, California. The risk of panic attacks was observed to be greater for identified cocaine users in this sample, as compared with subjects who did not use cocaine during the follow-up interval. The cocaine-panic association remained strong after statistical adjustment for preexisting psychiatric conditions, use of alcohol and marijuana, and suspected sociodemographic risk factors for panic attacks. The risk was greatest among cocaine users who reported no marijuana use during the follow-up interval (estimated relative risk = 13.0, 95% confidence interval: 2.24-75.8). The study also identified other determinants for panic attack, including sex, marital status, employment status, job prestige, major depression, and heavy drinking.

Adult↗
PubMedDate not supplied

Self-reported somatization symptoms associated with risk for extreme alcohol use.

BACKGROUND: The high rates of alcohol use in the population, the increased general health care utilization associated with untreated alcohol problems, and the often diffuse nature of somatization symptoms led us to hypothesize that somatization symptoms might be associated with alcohol use. OBJECTIVE: To determine whether a relationship exists between somatization symptoms and alcohol use. DESIGN: Multivariable logistic regression models were used to analyze existing cross-sectional and 1-year longitudinal survey data from the National Institute of Mental Health Epidemiologic Catchment Area Program. SETTING: Community households. SUBJECTS: Probability sample. INTERVENTIONS: None. MAIN OUTCOME MEASURES: Prevalent and incident heavy or binge drinking ("extreme alcohol use"). These measures are part of the National Institute of Mental Health Epidemiologic Catchment Area Program public core data set that was collected without regard for specific hypotheses. RESULTS: After control for sex, age, and education, 13 self-reported somatization symptoms showed independent cross-sectional associations to prevalent extreme alcohol use. The greater the number of somatization symptoms, the greater the risk, up to a maximum increased odds ratio of 138 to 1, of having comorbid extreme alcohol use when reporting all 13 somatization symptoms in the model. A smaller set of items was associated with the risk for subsequent new onset of extreme alcohol use. CONCLUSIONS: Self-reported somatization symptoms could add to the detection of extreme alcohol use. In addition, primary care and other physicians should consider somatic complaints as possible indicators of concurrent and future risk for extreme alcohol use. Potential benefits of better detection of extreme alcohol use include supporting primary and secondary prevention efforts and reduced expenditures for the diagnostic workup of somatic complaints.

Alcoholism↗