The relationship between negative symptoms and neuropsychological performance.
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Adolescent↗
Biomedical subjects
W G Iacono
Publications and source records attributed to W G Iacono.
Negative symptoms in the course of first-episode affective psychosis.
To determine whether the prognostic implications of negative symptoms apply to functional psychotic disorders other than schizophrenia, we investigated the significance of negative symptoms in the 18-month course of individuals experiencing a first episode of affective psychosis. Although negative symptoms were found to occur during the acute phase of a major depression or a bipolar disorder with psychotic features, they did not endure and had limited prognostic value. Further, the findings suggest that enduring negative symptoms may be specific to schizophrenia.
Adolescent↗
Development and validation of body rating scales for adolescent females.
OBJECTIVE: This present study was designed to develop and validate rating scales for body image assessment in adolescents. METHOD: The figures of the Figure Rating Scale (FRS; Stunkard, Sorenson, & Schlusinger, The genetics of neurological and psychiatric disorders, 1983, pp. 115-129) used in previous research seem more appropriate for research with adults. Accordingly, we developed two forms of a body rating scale (BRS) depicting adolescent females and administered these scales and the FRS to 315 female subjects. The subjects comprise three age groups, 11-year-olds, 17-year-olds, and their mothers, all participants in the epidemiologically based Minnesota Twin Family Study. Two independent observers also rated each subject. RESULTS: Intercorrelations among raters and scales and with body mass index were generally high and indicate comparability between the BRS measures and the FRS. DISCUSSION: The generally excellent psychometric properties of the new scales coupled with their face validity may make them a useful tool for body image research in children and adolescents.
Adolescent↗
Unequal rate of monozygotic and like-sex dizygotic twin birth: evidence from the Minnesota Twin Family Study.
It is generally believed that in Caucasian populations the rate of monozygotic (MZ) twinning is approximately equal to the rate of like-sex dizygotic (DZ) twinning so that representative samples of like-sex twins should contain approximately equal numbers of MZ and DZ twins. Recent evidence suggests, however, that the rate of DZ twinning in Caucasian populations has declined over the past 50 years so that there are now many more MZ than like-sex DZ twin births (Jeanneret and MacMahon, 1962; James, 1972; Mosteller et al., 1981; Doherty and Lancaster, 1986; Lykken et al., 1990). We report additional evidence of a higher rate of MZ than like-sex DZ twinning from Minnesota for the birth years 1971-1984. The convergence of evidence thus suggests that the observation of a greater number of MZ than DZ twins in a volunteer twin sample can no longer necessarily be taken as a sign of ascertainment bias.
Adolescent↗
An event-related potential investigation of posthypnotic recognition amnesia.
Forty-two individuals selected for high hypnotizability or for low hypnotizability were taught lists of words during hypnosis and assessed for recognition following hypnosis using event-related potential (ERP) procedures, both before and after the cue to reverse amnesia. A subgroup of low-hypnotizable participants were asked to simulate hypnotic behavior. All participants had larger late positive component (LPC) amplitudes to learned than to unlearned words, regardless of whether amnesia was reported. The highly hypnotizable participants who reported recognition amnesia, however, had significant changes in attention-related (P1 and N1) and recognition-related (N400 and LPC) ERP component amplitudes as a function of whether amnesia was reported. These data suggest that posthypnotic amnesia may involve alterations in the processes of attention, selection, and accessibility.
Amnesia↗
Internal consistency reliability of resting EEG power spectra in schizophrenic and normal subjects.
The reliability of resting electroencephalogram (EEG) power spectra was assessed for 49 normal and 44 schizophrenic subjects. We specifically examined internal consistency reliability to determine how much EEG data are necessary to ensure small measurement error. Twenty-one 8-s epochs of resting EEG were collected from each subject from site Cz. Epochs containing artifacts or blinks were eliminated. Power was computed in the bands delta (0.125-3 Hz), theta (3.125-8 Hz), alpha (8.125-13 Hz), beta1 (13.125-20 Hz) beta 2 (20.125-25 Hz) and beta 3 (25.125-30 Hz). Internal consistency was computed using coefficient alpha (Cronbach, 1951). Results for both groups indicated that eight artifact-free epochs of data were sufficient to give a coefficient alpha value of around .9. The schizophrenic and normal groups did not differ with respect to coefficient alpha. The proportion of artifacts in the data from the schizophrenics indicated that to obtain eight artifact-free epochs from members of each group, 40% more data would be required from the schizophrenics.
Adult↗
Effect of chronic alcohol use on smooth pursuit eye movements.
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Adult↗
Electrodermal activity and clinical status in chronic schizophrenia.
The present study investigated the association between electrodermal nonresponsiveness and clinical state in schizophrenia. Sixty-three patients with a DSM-III diagnosis of chronic schizophrenia served as subjects. Clinical status was assessed using multiple measures, including age of onset, symptom severity, illness duration, hospitalization history, global functioning, and occupational functioning. Electrodermal hypoactivity was found to be associated with poorer functioning and a more severe form of illness. In addition, hyporesponsive patients displayed more conceptual disorganization and alogia.
Adolescent↗
Comment on Levy et al. "Eye tracking dysfunction and schizophrenia".
We agree with Levy et al.'s conclusion (Schizophrenia Bulletin, Vol. 19, No. 3, 1993) that global quantitative measures of eye tracking dysfunction (ETD) have an important role in studies of ETD in schizophrenia. We clarify some misunderstandings of our own work contained in their review. In particular, an explanation is presented of how we computed a fit of our data to their Mendelian latent structure model, when testing for a fit to their hypothesis of essential genetic homogeneity. We also point out that our mixture analyses, as with our reported abnormality rates obtained by using cutting scores, are not in agreement with their reported rates of ETD in schizophrenia.
Attention↗
Resting EEG in first-episode and chronic schizophrenia.
We examined the frequency characteristics of the electroencephalogram (EEG) in 102 schizophrenic patients (44 first-episode and 58 chronic patients) and 102 normal comparison subjects. EEGs of schizophrenic patients had more delta (1-3 Hz) and theta (3.125-8 Hz) activity and less alpha (8.125-13 Hz) activity than normal comparison subjects. There were no significant differences in the EEG frequency composition of first-episode and chronic patients. Because first-episode and chronic patients were characterized by different disorder durations and treatment histories, the similarity of their EEGs suggests that EEG abnormalities are stable characteristics of schizophrenia and are not treatment-related epiphenomena. A principal components analysis of EEG power bands identified an augmented low frequency-diminished alpha component and a beta component. Schizophrenic patients had significantly higher scores on the augmented low frequency-diminished alpha component than did normal comparison subjects, and there was no significant group difference in scores on the beta component. The findings of this investigation suggest that EEG abnormalities in schizophrenia reflect aspects of brain dysfunction.
Acute Disease↗
Temporal stability of smooth-pursuit eye tracking in first-episode psychosis.
We evaluated the temporal stability of smooth-pursuit eye tracking in 38 schizophrenic, 42 nonschizophrenic psychotic (bipolar, depressive, paranoid psychotic, and schizophreniform), and 49 normal subjects. Pursuit performance was evaluated on two testing occasions separated by approximately 9.5 months. Retest reliability coefficients of root mean square (RMS) error scores for schizophrenic and normal subjects were .68 and .57, respectively. The reliability coefficients of RMS error scores for the nonschizophrenic psychotic patients ranged from .44 to .51. Level of psychological functioning was not significantly related to tracking performance, and most patients' pursuit performance remained stable despite changes in medication and clinical status. These results support the hypothesis that eye tracking dysfunction is a trait characteristic that can serve as a vulnerability indicator of schizophrenia.
Adult↗
Resting EEG in first-episode schizophrenia patients, bipolar psychosis patients, and their first-degree relatives.
We evaluated the resting electroencephalogram (EEG) of 50 first-episode schizophrenia patients and 55 of their relatives, 31 first-episode bipolar patients and 35 of their relatives, and 113 nonpsychiatric subjects and 42 of their relatives. The frequency characteristics of the EEG showed moderate stability for a subgroup of these subjects (n = 106) who were tested twice, approximately 9 months apart. Both the schizophrenia and bipolar patients showed a generalized pattern of increased delta and theta and decreased alpha activity. The bipolar patients demonstrated additional right hemisphere activity that was not present among the schizophrenia patients and nonpsychiatric subjects, a finding consistent with hypotheses concerning nondominant hemisphere involvement in the regulation of elated mood. The schizophrenia patients' female relatives and/or relatives with affective disorders and the bipolar patients had significantly reduced peak alpha frequencies. This finding may be related to reduced information processing capacity among these subjects.
Adolescent↗
Alcohol and the physiological detection of deception: arousal and memory influences.
Eighty male volunteers participated in an analogue study of the effects of alcohol intoxication at the time of a crime on the physiological detection of deception using control question and guilty knowledge techniques. Sixty-four of the subjects committed a mock crime and half of these were intoxicated during the crime. Sixteen subjects committed no crime and served as innocent controls. We found that intoxication at the time of the crime had no significant effect on polygraph test outcomes, although it did affect anticipatory arousal before the crime and subsequent memory for crime details. Manipulations designed to influence memory for crime details and arousal during the crime had differential effects for the two polygraph tests. On the guilty knowledge test, primed subjects who rehearsed specific details following the crime were more detectable than unprimed subjects. On the control question test, primed subjects were also more detectable, but only when arousal during the crime was high.
Adult↗
Biological and psychosocial predictors of job performance following a first episode of psychosis.
OBJECTIVE: The purposes of this study were 1) to evaluate occupational functioning 18 months after a first episode of psychosis and 2) to determine predictors of differential outcome. METHOD: Using a variety of sociodemographic, clinical, and psychophysiological measures, the project team assessed adults experiencing a first episode of schizophrenia (N = 33) or affective psychosis (N = 31). Identical measures were obtained from a comparison group (N = 46) who had no history of psychiatric disorder. Work performance was rated at entry into the study and 18 months later. RESULTS: At entry into the study, the schizophrenic subjects displayed the worst job performance, the asymptomatic individuals the best. The subjects with affective psychosis fell in between. Each of the two diagnostic groups evidenced postmorbid occupational decline. Three factors predicted good outcome in the schizophrenic group--good premorbid job performance, female gender, and scores on putative markers of biological vulnerability for the illness. For the affective disorder group, positive labeling by a significant other proved the only predictor of good outcome. CONCLUSIONS: These findings suggest that post-morbid occupational decline is common to both schizophrenia and affective psychosis. Past accomplishment and biological vulnerability predicted short-term course for these schizophrenic patients; psychosocial factors played a more prominent role in affective psychosis.
Adolescent↗
Handedness in first-episode psychotic patients and their first-degree biological relatives.
We evaluated the handedness of 58 schizophrenia patients and 54 of their relatives, 23 patients with major depression with psychosis and 24 of their relatives, 36 patients with bipolar psychosis and 33 of their relatives, and 119 nonpsychiatric subjects and 42 of their relatives. Computerized tomography measures were also available for a subset of the psychotic patients. The schizophrenia patients were significantly more left-handed than any of the other groups, and increased sinistrality was also associated with larger lateral ventricle to brain area ratios. The relatives of the schizophrenia patients did not significantly differ on handedness from either the relatives of the affective psychosis patients or the nonpsychiatric subjects. Our findings do not support the notion that left-handedness in schizophrenia is genetically influenced. More research with larger family member data sets is warranted to further explore this possibility.
Adolescent↗
The association between lithium carbonate and smooth pursuit eye tracking among first-episode patients with psychotic affective disorders.
The association between treatment with lithium carbonate and smooth pursuit eye tracking performance was investigated in first-episode patients with psychotic affective disorders. The horizontal pursuit performance of patients with major depression and bipolar disorder who were receiving lithium carbonate was contrasted with that of patients not receiving lithium carbonate. In addition, the accuracy and quality of pursuit eye tracking was examined in bipolar patients whose lithium status changed from the time of initial testing to the time of retest 10 months later. For the combined group of depressed and bipolar patients, treatment with lithium carbonate was not associated with worse pursuit performance. Bipolar disordered patients on lithium did not differ in tracking proficiency from those not on lithium; bipolar patients whose lithium status changed from intake to retest also did not display a significant change in pursuit performance.
Adult↗
Establishing the onset of psychotic illness.
OBJECTIVE: To date, the literature has provided no standardized, replicable method for establishing illness onset. The authors describe a method for dating the first appearance of prodromal signs of psychotic illness, the emergence of an acute episode, and the initiation of treatment seeking. METHOD: Using reports by family and friends about a sample of 141 subjects with first-episode psychosis, the investigators derived a checklist of behaviors describing the evolution of various phases of illness. Supplied with the checklist, clinician pairs independently rated the critical phases in the evolution of illness: first appearance of noticeable symptoms, first appearance of prominent psychotic symptoms, and initiation of treatment seeking. RESULTS: The judges achieved good reliability in assigning age at the first appearance of psychotic symptoms and at initiation of treatment seeking. Judging the beginning of the prodrome proved more difficult. Insidious onset proved as characteristic of affective psychosis as of schizophrenia, while treatment lag--the interval between emergence of acute psychotic symptoms and initiation of treatment seeking--was longer for schizophrenia than for affective psychosis. Onset of schizophrenia occurred earlier in women than in men. Depression with psychotic features appeared earlier in men than women. CONCLUSIONS: Although dating the onset of illness phases is probably feasible, efforts to improve reliability must continue. The study results challenge beliefs about gender differences in age at onset.
Adolescent↗
A strategy for elucidating genetic influences on complex psychopathological syndromes (with special reference to ocular motor functioning and schizophrenia).
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Alleles↗