Is there atypical handedness in schizophrenia?

Ninety-three schizophrenic patients and 105 normal controls were tested in a single session on an 8-item repeat-administration handedness test. The schizophrenic group, in contrast to the normal controls, showed a shift in the distribution away from right-handedness, which was due to an increase in the proportion of mixed-handers. Additional analyses revealed that the increase in mixed-handedness was largely due to an increase of within-item variability in the schizophrenic group, which we refer to as ambiguous handedness. Nearly 20% of the schizophrenic patients were inconsistent on 3 or more items compared with 3.8% of the normal controls. This increased incidence of atypical handedness is discussed within the context of disorders of attention and neurodevelopment.     

The contingent negative variation laterality and dynamics in antisaccade task in normal and unmedicated schizophrenic subjects

Contingent negative variation (CNV) topography, hemispheric asymmetry and time-course were investigated in healthy subjects and non-medicated paranoid schizophrenic patients in two antisaccade paradigms with the short (800-1000 ms) and long (1200-1400 ms) durations of the fixation period. EEG and electrooculogram (EOG) were recorded. Saccade characteristics and mean amplitudes of slow cortical potentials time-locked to peripheral target were analyzed in 23 healthy volunteers and 19 schizophrenic patients. Compared to healthy control subjects, schizophrenic patients had significantly slower antisaccades and committed significantly more erroneous saccades in the both antisaccade tasks. The prolongation of the fixation period resulted in noticeable decrease of error percent in patients group. The analysis of CNV time-course has revealed two distinct stages in both groups. The early CNV stage was represented by a negative wave with the maximal amplitude over midline fronto-central area, and the late stage was characterized by increased CNV amplitude at the midline and left parietal electrode sites. In healthy subjects the simultaneous activation of frontal and parietal areas was observed in the paradigm with the shorter fixation interval; the increase of the fixation period produced consecutive activation of these areas. Schizophrenic patients' CNV amplitude was generally smaller than that of healthy subjects. The most pronounced between-group differences of the negative shift amplitude were revealed at frontal electrode sites during the early CNV stage in both modifications of the antisaccade task. The deficit of frontal activation revealed in patients at the early stage of antisaccade preparatory set in both antisaccadic paradigms may be related to pathogenesis of paranoid schizophrenia.     

Sex differences in completed suicide by schizophrenic patients: a meta-analysis

A meta-analysis was conducted on all studies of suicide mortality in follow-up studies of schizophrenic patients that presented data for male and female patients separately. The percentage of deaths from suicide was significantly greater for the male schizophrenic patients than for the female schizophrenic patients in studies where both sexes were included. Regression equations devised to predict the percentage of deaths from suicide after all of the sample had died estimated that 0.50% of male schizophrenic patients would die from suicide as compared to 0.20% of female schizophrenic patients. Suggestions are made for future research.     

Suicidal tendencies in schizophrenic patients hospitalized for the first time

180 (15%) patients from 1208 first-hospitalized schizophrenic patients had suicidal tendencies. Our findings show that the suicidal tendencies of schizophrenic patients have their own features. These conclusions can be supported by the differences between the determinants of the suicidal tendencies of schizophrenic and non-schizophrenic population; such different determinants are: sex, age, family and suicidal method. Suicidal tendencies are more frequent among patients without formal thought disturbances. We explain this fact with an "incoherence of decision processes". The features of the suicidal tendencies of schizophrenic patients are based on the grounds of psychosis own dynamic.     

Functioning of the phonological loop in auditory hallucinations

Two experiments designed to assess the functioning of the phonological store and loop were carried out with schizophrenic patients experiencing auditory hallucinations, schizophrenic patients not experiencing hallucinations and normal subjects. In the first experiment, phonological encoding was assessed. Although both groups of psychiatric patients performed more poorly overall than the normal subjects, there were no significant differences between the performances of the hallucinating and nonhallucinating patients. In the second experiment, the unattended speech effect (a phenomenon thought to reflect the functioning of the phonological store in normal subjects) was assessed in hallucinating schizophrenic patients, non-hallucinating schizophrenic patients and normal controls. The psychiatric patients performed more poorly overall than the normal subjects, but there was no evidence of abnormal functioning of the phonological store or loop in either patient group. Overall, the findings indicate that phonological store and loop abnormalities are not implicated in the experience of auditory hallucinations.     

An event-related brain potential substrate of disturbed response monitoring in paranoid schizophrenic patients.

Response monitoring in schizophrenic patients and healthy controls was assessed by measuring performance and event-related brain potentials in the flanker priming task. Three visual-context conditions were construed: Flankers and targets pointed either into the same direction or into different directions. Stimuli without any response assignment were used as flankers in the neutral context condition. The schizophrenic patients were further subdivided into paranoid (n = 19) and nonparanoid (n = 10) patients and compared with healthy controls (n = 18). Performance scores revealed that the flankers induced a similar degree of distraction by visual context in all 3 groups. Although the schizophrenic patients showed normal error correction performance, the error negativity (NE) was significantly reduced in paranoid schizophrenic patients. The attenuation of the NE possibly reflects disturbed response monitoring in these patients.     

Temporal information processing and psychopathology.

Prior studies showed impaired temporal discrimination by schizophrenic and neurologic patients reflected in decreased information transmission. This report describes a study of 8 more carefully diagnosed schizophrenic patients, separating those with neurologic signs. Using temporal discrimination tasks involving two psychophysical methods, 8 schizophrenic patients with no organic signs did not differ from 17 nonpsychotic, nonorganic patients; and organic group (n = 5) transmitted less information than the other patient samples. It is suggested that prior results were a product of casual diagnosis that ignored organic factors; reduced efficiency of temporal processing is associated predominantly with neurologic impairment.     

Communication deviance in families of schizophrenic and manic patients

Levels of communication deviance (CD) distinguish parents of schizophrenic patients from parents of nonpsychotic patients, but the prevalence of intrafamilial CD in other psychotic disorders has not been examined. Levels of CD were compared across biological parents of schizophrenic (n = 39) and bipolar manic (n = 16) patients and across patients themselves. CD ratings were based on Thematic Apperception Test protocols (parents only) and family interactions (parents and patients). Total levels of CD did not distinguish between groups of parents or patients. However, instances of odd word usage were more frequent among parents of manic patients than among parents of schizophrenic patients on both CD measures. Also, during the interaction task, odd word usage was more frequent among manic patients, whereas schizophrenic patients made more ambiguous references. Results suggest that high levels of intrafamilial CD are not unique to schizophrenia.     

Patientensuizid im psychiatrischen Fachkrankenhaus

Suicide prevention especially with psychiatric inpatients is traditionally a very important aspect of psychiatric treatment. During the 1970s and 1980s there was a noticeable increase in so-called hospital suicides in Germany, especially suicides of schizophrenic inpatients. The number of psychiatric inpatient suicides has currently decreased again and a shift to more depressive suicides has also been observed. Furthermore questions which are asked in court are presented and discussed.     

Self-focused attention in schizophrenic patients with and without auditory hallucinations and normal subjects: A comparative study

Self-focused attention has been implicated in a number of psychiatric disorders, but little research has examined this in schizophrenic subjects. In this study, a sample of schizophrenic patients experiencing auditory hallucinations, schizophrenic patients not experiencing auditory hallucinations and normal controls were asked to complete the private self-consciousness subscale of the Self Consciousness Scale. It was found that patients experiencing auditory hallucinations exhibited significantly higher levels of self-focus than those not experiencing hallucinations, although they did not differ from normal subjects. It was also shown that level of self-focus predicted whether or not subjects experienced hallucinations. These results, and their implications, are discussed with reference to the literature.     

Loss of Discriminative “Power” of the MMPI with Older Psychiatric Patients

MMPIs were obtained from four groups of 20 hospitalized male patients which differed in age (18–28 years vs 45–59 years) and psychiatric diagnosis (schizophrenic vs nonschizophrenic). The MMPI discriminated between young schizophrenic and nonschizophrenic patients but did not discriminate between older schizophrenic and nonschizophrenic patients. The apparent loss of discriminative “power” of the MMPI with older patients was interpreted as supporting the importance of the often overlooked nonpathological characteristics of the psychological test subject.     

A study of blocking and other response variables in psychotic, brain-damaged and personality-disturbed patients

An experiment was conducted on the hypothesis that the differences in personality and behaviour of various groups of psychiatric patients would be reflected in a serial visuo-motor task. The patients' errors, blocks and RT variability were ascertained and significant differences emerged between the groups. All of the experimental groups—chronic schizophrenic, brain-injured psychotics, brain-injured non-psychotics—differed from the disturbed, non-psychotic control group on all of the variables tested. A group of paranoid schizophrenic patients, however, differed from the controls in only two respects, i.e. variability and number of responses per minute. The paranoid schizophrenic group produced a strikingly different performance from that of the chronic schizophrenic group. The latter group exceeded all other groups in both the frequency and duration of blocks.     

Exaggerated leftward bias in the mental number line of patients with schizophrenia

Several visuo-motor tasks can be used to demonstrate biases towards left hemispace in schizophrenic patients, suggesting a minor right hemineglect. Recent studies in neglect patients used a new number bisection task to highlight a lateralized defect in their visuo-spatial representation of numbers. To test a possible lateralized representational deficit in schizophrenia, we used the number bisection task in 11 schizophrenic patients compared to 11 healthy controls. Participants were required to orally indicate the central number of an interval orally presented. Whereas healthy subjects showed no significant bias, schizophrenic patients presented a significant leftward bias. Therefore, these results suggest an impairment in higher order representations of the number space in patients with schizophrenia, an impairment that is qualitatively similar to the deficit described in neglect patients.     

Reported childhood trauma and suicide attempts in schizophrenic patients

Childhood traumas are associated with suicidal behavior but this aspect has not been examined in relation to schizophrenia. In this study, 50 chronic schizophrenic patients who had attempted suicide were compared with 50 chronic schizophrenic patients who had never attempted suicide for their scores on the 34-item Childhood Trauma Questionnaire (CTQ). It was found that schizophrenics who had attempted suicide reported significantly higher CTQ scores for emotional abuse, physical abuse, sexual abuse, emotional neglect, and physical neglect than schizophrenics who had never attempted suicide. Therefore, childhood trauma may be a risk factor predisposing schizophrenic patients to attempt suicide.     

Self-structure in schizophrenia

This study used a set-theoretical model to construct self-perception structures and person-perception structures for 10 recently hospitalized schizophrenic patients, 10 nonschizophrenic patients recently hospitalized for depression, and 10 nonpsychiatric subjects. Overall self-perception structures were significantly less elaborated in the schizophrenic patients when compared with either the psychiatric or the nonpsychiatric comparison group. No comparable differences were found for measures taken from the person-perception structures. The degree of elaboration of self in the particular context of self as psychiatric patient was found to be correlated (r = .74, p less than .01) with Global Assessment Scale ratings of current functional level in the schizophrenic group.     

Depression and suicide in schizophrenic patients

This study supports the idea that schizophrenic patients represent a distinctive subgroup of patients who can suffer from a major depressive illness and also can commit suicide. The study showed that 22.4% of the schizophrenic population in a medium-sized psychiatric facility showed severe depressive symptoms that met the criteria for the diagnosis of a major depressive episode according to the DSM-III classification. Seven patients committed suicide during the acute phase of the illness--five during hospitalization, and two within a year of discharge. Nine patients attempted suicide during the hospitalization period, and 10 attempted suicide within a year of discharge. Nearly one-third (215) of the patients were readmitted during that year because of a recurrence of acute schizophrenic symptoms; of these, 84 were having severe depressive symptoms. The study also provides indications of the causes of suicide in these patients.     

Schizophrenia--a high-risk factor for suicide: clues to risk reduction.

Suicide is the chief cause of premature death among schizophrenic persons. The lifetime incidence of suicide for patients with schizophrenia is 10% to 13% compared to a general population estimate of about 1%, and is quite close to that observed among those with major affective disorder. The magnitude of increased risk for suicide among schizophrenics peaks before middle age and declines thereafter, although schizophrenic persons tend to be at increased risk throughout the life span. Among psychiatric patients, schizophrenics are overrepresented among suicides, and often schizophrenics constitute the majority of inpatient suicides. It is important in evaluating suicide risk among schizophrenic persons to assess depression and suicidal ideation especially during index admission and during acute phases of the illness. It is noteworthy that schizophrenic persons often commit suicide as the overall level of psychopathology decreases during a nonpsychotic phase. Research has yielded salient risk factors for suicide in schizophrenic persons and "types" of especially vulnerable patients, even though statistical prediction of individual suicides has not proven effective.     

Identifying schizophrenia by means of scale 8 Sc of the MMPI

A sample of 38 schizophrenic inpatients was found to achieve significantly higher mean scores on Scale 8 of the MMPI relative to 38 schizophrenia-spectrum and 38 control patients regardless of whether K- or non-K-corrected scores were used. However, when patients were individually classified by means of a cutting score (greater than or equal to 70), only K-corrected scores accurately discriminated between schizophrenic and control patients at a statistically significant level.     

Effects of increasing cognitive load on sustained attention tasks in schizophrenic disorders and schizotypy

In this study we analyze the attentional performance using different cognitive load attentional tasks: low-load cognition (0-CPT) and high-load cognition (DS-CPT). Participants were a group of schizophrenic patients and two groups of normal population psychometrically classified as low schizotypy and high schizotypy according to the SPQ. Our results show that schizophrenic patients were more sensitive to increments on cognitive load, being their attentional performace worse than the rest of the groups. The lack of significant findings in vigilance on the schizotypal traits group is discussed in terms of conceptual and methodological issues about the utility of psychometric strategies to identify vulnerable populations within the spectrum of the schizophrenic disorders.     

Tryptophan-loading in schizophrenia and endogenous depression

In 95 schizophrenic patients, 20 endogenous depressed patients and 39 control subjects the level of plasma tryptophan was determined after oral load of L-tryptophan (50 mg/kg) in range of 3 hours. Among the groups quantitative and specially qualitative differences were observed in course of tryptophan. In the group of schizophrenic patients it is possible to exactly differentiate a subgroup with similar psycho-pathological symptomatic by means the course of tryptophan.