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Biomedical subjects

B A Clementz

Publications and source records attributed to B A Clementz.

47 records · Page 3Linked to original sources
PubMed1992

A family study of nailfold plexus visibility in psychotic disorders.

It has been proposed that the nailfold subpapillary plexus visibility score (PVS) may be a marker of susceptibility to schizophrenia. To further investigate this hypothesis, we evaluated plexus visibility in a sample of 61 chronic schizophrenics, a large sample of first-episode psychotic patients and their first-degree relatives (50 with schizophrenia, and 51 of their relatives; 29 with schizophreniform disorder, 30 of their relatives; 32 with major depression with psychotic features, 35 of their relatives; 33 with a bipolar disorder with psychotic features, 32 of their relatives), and 169 normal control subjects. Group comparisons demonstrated that (1) the probands with chronic schizophrenia, first episode schizophrenia, and schizophreniform disorder did not differ from one another on PVS; (2) these subjects combined had higher PVS ratings than the other two proband groups and normal subjects combined (who did not differ); and (3) none of the relative groups significantly differed from either one another or the normal subjects. On the other hand, relatives of schizophrenia spectrum probands with high PVS (greater than or equal to 10.0) had higher PVS ratings than the relatives of such probands with low PVS. Patterns of familial correlations suggested that PVS was moderately heritable (0.40). There was no evidence that nonadditive genetic variation influenced the trait.

Adult↗
PubMed1992

Smooth-pursuit eye movement dysfunction and liability for schizophrenia: implications for genetic modeling.

Forty-one nonpsychiatric subjects, 38 probands with schizophrenia, and 99 of their relatives were studied. Oculomotor functioning was bimodally distributed for probands and relatives. Oculomotor dysfunction was not present in all families with a schizophrenic proband. In those families in which it was present, there were significant phenotypic correlations between oculomotor functioning and schizophrenia-related characteristics. The patterns of familial resemblance in the families in whom oculomotor dysfunction was present were consistent with nonadditive genetic variance contributing both to oculomotor dysfunction and to the relationship between oculomotor dysfunction and clinical symptoms. These results suggest that schizophrenia may be etiologically heterogeneous and that oculomotor dysfunction may help to identify nonadditive genetic variance for this disorder.

Adult↗
PubMed1992

Smooth pursuit ocular motor dysfunction in schizophrenia: evidence for a major gene.

OBJECTIVE: Evidence suggests that poor eye tracking relates to genetically transmitted vulnerability for schizophrenia. The authors tested competing models for the genetic transmission of poor eye tracking in a search for major gene effects. METHOD: Samples from three studies (conducted in Minneapolis, New York, and Vancouver, B.C.) were pooled. Probands (N = 92) were diagnosed as schizophrenic by DSM-III criteria. Of the comparison subjects (N = 171), Vancouver patients were an epidemiologic first-episode group; at other sites unselected admitted patients were studied. First-degree relatives (N = 146) of 65 probands were also studied. Eye tracking was measured while subjects followed a horizontally moving, sinusoidally driven (0.4 Hz) spot of light on a screen. Performance was quantified by root mean square error. Data analysis was by complex segregation analysis (Bonney's class D regressive models). RESULTS: A single major gene is needed to account for poor eye tracking in schizophrenic patients and their relatives. This gene alone can explain about two-thirds of the variance in eye tracking performance. A single gene alone (regardless of dominance) will, however, not account for the data; polygenic factors are also required. CONCLUSIONS: Results support postulation of a single gene for ocular motor dysfunction, which may be a risk factor for schizophrenia. Eye tracking may be useful as a gene carrier test in genetic studies of schizophrenia.

Adolescent↗
PubMed1992

Personality and clinical characteristics in patients with trichotillomania.

BACKGROUND: Trichotillomania, a disorder of self-directed hair pulling, has been the subject of few systematic studies. Although personality characteristics and disorders are often noted to coexist with trichotillomania, no thorough assessment of comorbidity with DSM-III-R Axis II disorders has been published. The present study was conducted to evaluate personality disorders and other personality characteristics in a large outpatient population of trichotillomanics and to compare these findings with those in a nontrichotillomanic comparison group. METHOD: Forty-eight outpatient female trichotillomanics were evaluated with the Structured Interview for DSM-III-R Personality Disorders (SIDP-R) and the revised version of the Minnesota Multiphasic Personality Inventory (MMPI-2). Personality disorders and personality cluster symptom scores from the SIDP-R and MMPI-2 scales were compared with those derived from a comparison group of 48 age-matched female outpatient psychiatric patients. RESULTS: Forty-two percent of the trichotillomanic group met criteria for a personality disorder. The only statistically significant difference in frequency of diagnoses between the trichotillomanic and comparison groups was a greater frequency of borderline personality disorder in the comparison group. Trichotillomanics demonstrated significantly less SIDP-R cluster A personality symptoms as well as less depression and better psychological adjustment on the MMPI-2. CONCLUSION: Our study suggests that no particular personality disorder or trait characterizes female trichotillomanics. Female trichotillomanics seeking psychiatric intervention appear to have better psychological adjustment and less psychopathology in general than other psychiatric outpatients.

Adolescent↗
PubMed1991

Familial prevalence and coaggregation of schizotypy indicators: a multitrait family study.

Schizophrenic probands (n = 17), their first-degree relatives (n = 61), and medically and psychiatrically screened normal control subjects (n = 18) were studied with structured interviews for DSM-III Axis I disorders and schizotypal personality disorder, questionnaire measures of schizotypy, measures of smooth-pursuit eye movement dysfunction, and attention dysfunction. Schizophrenic subjects scored abnormally on essentially all measures. Relatives differed significantly from control subjects on most measures. Correlational analyses indicate that many characteristics tested in these measures run together in families. The data are consistent with the hypothesis that a single vulnerability dimension or typology, presumably in part genetically transmitted, may account for phenotypically distinct abnormalities. These traits, taken together, may have joint usefulness for identifying persons with a predisposition to schizophrenia.

Adult↗
PubMed1991

Psychometric detection of schizotypy: perceptual aberration and physical anhedonia in relatives of schizophrenics.

We administered scales of Perceptual Aberration (PERAB) and Physical Anhedonia (PHYSAN), traits that may be related to risk for schizophrenia, to 54 schizophrenics, 146 of their first-degree relatives (evaluated for schizophrenia-related disorders), and 178 normal subjects (screened for psychotic disorders in them or their relatives). For both scales, there was a significant effect of group membership. For the PERAB scale, the schizophrenics had higher scores than the normal subjects, who had higher scores than the relatives. For the PHYSAN scale, schizophrenics had higher scores than their relatives, who had higher scores than the normal subjects. Patterns of familial correlations also suggested that physical anhedonia, but not perceptual aberration, may be familial among schizophrenics and their relatives. The PHYSAN scale, but not the PERAB one, may be a useful indicator of liability for schizophrenia among the relatives of affected probands.

Adult↗
PubMed1991

Phenotypic correlations between oculomotor functioning and schizophrenia-related characteristics in relatives of schizophrenic probands.

Abnormalities of visual pursuit tracking are frequent in the first-degree relatives of probands with schizophrenia. The relationship between oculomotor abnormalities and schizophrenia-related characteristics in those family members, however, has received little attention. Fifty-three first-degree relatives of 24 probands with schizophrenia were evaluated for the presence of schizophrenia-related characteristics using both interview (Schedule for Schizotypal Personalities) and questionnaire (Chapman scales). The family members also had their eye movements recorded during pursuit tracking tasks and scored for gain in both the frequency and time domains, and saccadic intrusions. Social-interpersonal schizophrenia-related features were significantly related to both time- and frequency-domain gain calculations. It appears that abnormalities in the smooth-pursuit oculomotor system may be associated with symptoms conjectured to be most closely related to a genetic diathesis for schizophrenia. These findings provide further evidence that oculomotor abnormalities may be related to risk for this disorder.

Adult↗
PubMed1990

Pursuit gain and saccadic intrusions in first-degree relatives of probands with schizophrenia.

Oculomotor functioning of 26 probands with schizophrenia, 12 spectrum and 46 nonspectrum first-degree relatives, and 38 nonpsychiatric control subjects was evaluated. Spectrum relatives had more anticipatory saccades (ASs) and lower pursuit gain than nonspectrum relatives, who had more ASs and lower pursuit gain than control subjects. Probands also had lower pursuit gain than nonspectrum relatives and control subjects but did not differ from other groups on AS frequency. Control subjects had more globally accurate pursuit tracking (root mean square [RMS] error deviation) than both relative groups, whereas probands had the poorest RMS scores. Square wave jerk frequency did not differentiate the groups. Attention enhancement affected the frequency of ASs but did not affect either the other intrusive saccadic event or RMS scores. These results offer evidence that eye-movement dysfunction may serve as a biological marker for schizophrenia.

Adolescent↗
PubMed1990

Is eye movement dysfunction a biological marker for schizophrenia? A methodological review.

There is a high prevalence of eye movement dysfunction (EMD) in persons with schizophrenia and their first-degree relatives. Studies addressing the prevalence, stability, familial transmission, and psychological correlates of EMD in persons from both psychiatric and general populations offer suggestive evidence that this abnormality may serve as a biological marker for schizophrenia. Although these findings are promising, their significance for elucidating the diagnostic bandwidth, pathophysiology, and genetics of this disorder remains to be determined. More precise characterization of ocular motility, perhaps when used in conjunction with global measures of pursuit adequacy, may be essential for clarifying the pathophysiological and genetic significance of EMD for schizophrenia. Recent research efforts are beginning to identify particular abnormalities that could serve as more specific biological markers for schizophrenia.

Eye Movements↗
PubMedDate not supplied

Behavioral and brain imaging studies of saccadic performance in schizophrenia.

Data are reviewed from a series of saccadic studies demonstrating that schizophrenia subjects have normal performance on some types, and abnormal performance on other types, of tasks. Normal refixation saccade characteristics and BOLD signal change among schizophrenia subjects suggest that basic saccade generating circuitry is functionally intact among these subjects. Schizophrenia patients and their relatives, however, demonstrate difficulty with saccadic inhibition, a function ostensibly mediated by DLPFC circuitry. We review additional evidence for saccadic inhibition being associated with prefrontal circuitry provided by EEG and fMRI data. Minimum norm analysis of EEG data suggests that dipolar activity preceding correct antisaccades occurred preferentially in prefrontal cortex. Furthermore, there is an indication from the fMRI data that prefrontal activity may be increased in normal, but not in schizophrenia, subjects during antisaccade tasks. These data suggest that a research program relying on multiple functional imaging technologies may be helpful for furthering our understanding of schizophrenia's essential neuropathology.

Brain Mapping↗