Acute Schizophrenics Research Articles

The dimensional complexity of the EEG in untreated acute schizophrenics, in persons in remission after a first schizophrenic episode, and in controls

The dimensional complexity of the EEG in untreated acute schizophrenics, in persons in remission after a first schizophrenic episode, and in controls

Strange attractors, chaotic behavior and informational aspects of sleep EEG data.

In order to perform a nonlinear dimensional analysis of the sleep EEG, we applied an algorithm proposed to calculate the correlation dimension D2 of different sleep stages. D2 characterizes the dynamics of the sleep EEG, estimates the degrees of freedom, and describes the complexity of the signal under study. An attempt is made to correlate dimensionality analysis and informational aspects of the sleep EEG. Information processing by the brain during different sleep stages of healthy subjects under the influence of lorazepam and in unmedicated acute schizophrenics is estimated.

Contextual Effects on Choice Reaction Time and Accuracy in Acute and Chronic Schizophrenics Impairment in Selective Attention or in the Influence of Prior Learning?

Two hypotheses were tested concerning the nature of the cognitive dysfunction in schizophrenia: (a) that there is a broadening of selective attention; and (b) that there is an impairment in associational learning. RDC-diagnosed acute and chronic schizophrenics and normal controls carried out a choice reaction time (RT) task in which conflict between the correct response to a target (a letter in the centre of a computer screen) and that cued by simultaneously presented flankers (two letters either side of the target) increased RT. For 80 ('valid') trials, flankers and targets were consistent in the response cued (pressing a button with either left or right hand); on 8 ('invalid') trials they conflicted. On invalid trials there was a slowing of RT, and an increase of errors for left-hand responses. Chronic schizophrenics showed the same reactions to cue validity as normal controls, both groups differing significantly from acute schizophrenics. For the latter, the RT data supported hypothesis (b), but the error rates appeared to support hypothesis (a).

Doppelblindvergleich von 3 × 75 mg Zotepin und 3 × 4 mg Haloperidol bei akut schizophrenen Patienten

To assess the efficiency/risk ratio, fixed doses of zotepine and haloperidol were compared by means of a double-blind study in acute schizophrenics over a 4-week period. The assessment tools were BPRS, CGI, and the Simpson-Angus scale for the extrapyramidal disturbances, and a free report on side effects. No differences between the groups were found in respect of efficacy. According to the Simpson-Angus scale, the patients who had been treated with zotepine achieved better values, this being a general trend. There were significant differences according to the free report on side effects. Especially at onset of treatment, the patients treated with zotepine complained of tiredness. Partly marked extrapyramidal disturbances were seen in the patients who had been treated with haloperidol.

Computer-assisted attention training in schizophrenics

The evaluation of a computer-assisted attention training program is compared with a cognitive group training program. Both programs were devised to reduce cognitive deficits in schizophrenics. The training programs were given to 30 acute schizophrenics and 30 healthy subjects. Both were shown to be effective in reducing distraction of schizophrenics in reaction-time tasks. By means of training, schizophrenics may attain the same results in reaction time tasks as healthy individuals. The results are discussed under theoretical, methodical and practical aspects.

Zur Wirksamkeit der neuroelektrischen Therapie (NET) bei pharmakotherapeutisch resistenten endogenen Psychosen

A retrospective chart review of 50 pharmacotherapeutically resistant patients was performed after treatment with NET in 1986-1988. 28 patients suffered from schizophrenia and 22 from affective psychosis. In contrast to literature where NET as therapy of first choice has favourable results in depression in this study 60.7% of the treatment resistant acute schizophrenics responded well to NET. 3 months after discharge from hospital 9 schizophrenics (32.1%) but only 3 patients with affective psychosis (13.6%) presented a 'good' outcome (full remission). A longer duration of schizophrenia (more than 5 years since first manifestation) and a good response to neuroleptics in history was predictive for a good actual NET response (14 of 17 patients), whereas 7 of 11 patients suffering from schizophrenia less than 3 years without any period of full remission on neuroleptics were also non-responders to NET.

Discriminating Schizophrenics from Borderline Patients: Study with the Holtzman Inkblot Technique

The present study tried to discriminate acute (n = 25) and chronic schizophrenics (n = 25) from borderline patients (BLP; n = 30) on the basis of deviant verbalizations as assessed by the Holtzman Inkblot Technique (HIT). A 30-card version of the HIT was used. It was possible to separate BLPs and schizophrenics with quite good results: 77% of the BLPs, 80% of the acute schizophrenics and 92% of the chronic schizophrenics could be classified correctly based on the less severe deviant verbalizations (DVs) which were more frequent in the BLPs and based on the most severe forms of DVs, i.e. Incoherence, neologism and Perseveration (which were more frequent in the schizophrenic patients). Furthermore, it could be demonstrated that BLPs can be separated from neurotics using the 30-card version of the HIT, the resulting scores being nearly as high as those on the basis of the 45-card version. In another comparison, neurotics (n = 30) were discriminated from normals (n = 35) using the less severe DVs, which were more frequent in the neurotics: here, 74% of the normals and 73% of the neurotics could be classified correctly.

Elevated Plasma Dopamine Concentrations in Unmedicated Acute Schizophrenics

The authors studied the concentrations of plasma catecholamines in 23 acute schizophrenics, 28 healthy controls, 20 chronic schizophrenics, and 26 otherwise diagnosed psychiatric cases. Blood samples were taken from the consecutively admitted acute schizophrenics before the administration of antipsychotic drugs and catecholamines were assayed with a high performance liquid chromatography and electrochemical detector. Plasma adrenaline in the acute schizophrenics and the other psychiatric patients was significantly elevated in comparison with the healthy controls. There were no significant differences in the noradrenaline concentrations among the four groups. The plasma dopamine concentrations in the acute schizophrenics were also higher than those in the healthy controls. It is unlikely that physical exercise caused the elevation of dopamine in the acute schizophrenics. There was no significant correlation between plasma catecholamines and BPRS scores in the acute schizophrenics.

Eye movements in acute, chronic, and remitted schizophrenics

Eye movements in 10 acute schizophrenics, 50 chronic schizophrenics, 20 remitted schizophrenics, 25 methamphetamine psychotics, 21 temporal lobe epileptics with left-sided spike focus (l-focus), 12 temporal lobe epileptics with right-sided spike focus (r-focus), and 50 normal controls were examined with an eye mark recorder while they viewed geometric figures. The eye movements while viewing an original “S”-shaped figure for 15 sec were analyzed. Each schizophrenic group and methamphetamine psychotics had significantly less eye fixations than the normal controls and temporal lobe epileptics (r-focus and l-focus). The chronic schizophrenics had significantly shorter mean eye scanning length (MESL) than the other six groups. Each subject was then shown two other figures slightly different from the original and was requested to compare them with the original. After comparing them, the subjects were asked the question, “Are there any other differences?” The 5-sec eye movements during the response to this question were scored using the Responsive Search Score (RSS). The schizophrenic groups had a significantly lower RSS than the nonschizophrenic patient groups and the normal controls. In the chronic schizophrenics, there was a significant negative correlation between the RSS and negative symptoms. These results suggest that the MESL can be an indicator of a chronic process of schizophrenia, and that lowering of the RSS may be nosologically specific indicator for schizophrenia.

Linguistic Performance in Schizophrenia: a Comparison of Acute and Chronic Patients

A computer-assisted analysis of samples of free speech from acute schizophrenics (n = 50), chronic schizophrenics (n = 27) and normal subjects (n = 50) enabled a comparison of the linguistic profiles of the three groups. The chronic group consistently emerged as the most impaired, on measures of complexity, integrity (error) and fluency of speech, with the acute patients performing less well than normal speakers but better than chronic patients. Demographic differences could account for only a small number of the linguistic differences. A comparison of chronic schizophrenics from the community and those from long-stay wards suggested that their poor linguistic performance was in some way related to the illness process and not to institutionalisation. Three possible explanations for these results were considered, particularly the possibility that low complexity of speech, negative symptoms and poor outcome are in some way related.

The Kamin blocking effect, incidental learning and psychoticism

The Kamin blocking effect consists in impaired learning of an association between a conditioned stimulus (CS2) and an unconditioned stimulus (UCS) if CS2 is presented simultaneously with a different CS (CS1) already associated with the UCS. It is well established with animal but not human subjects. In the two experiments presented here, the effect was clearly demonstrated with UCS = a computer-presented yellow square, CS1 = a blue square and CS2 = a noise (Expt 1) or two smaller white squares (Expt 2). The Kamin effect has, by some theorists, been attributed to switching of attention away from CS2, which conveys only redundant information. If so, the size of the effect should co-vary with indices of selective attention commonly used with human subjects. As predicted, the blocking effect was found to be smaller in subjects who displayed a high degree of incidental learning in either of two tasks in which intentional vs. incidental learning corresponded to (1) words vs. word position, or (2) a target initial word letter vs. non-target initial letters. We report elsewhere that the blocking effect is absent in acute schizophrenics. In the present experiments, however, there was no systematic relation between any of four measures of psychoticism, or intelligence, and either the blocking effect or incidental learning.

Selective dopamine D2 antagonist and prolactin response in acute schizophrenia — Results from remoxipride studies

1. 1. In a double-blind dose finding study prolactin was assessed at baseline and end of treatment in three groups of acute schizophrenics receiving low, intermediate and high doses of remoxipride as compared to a controlled group that received haloperidol. 2. 2. Remoxipride only in high doses (300–600 mg daily) has produced a modest increase in prolactin levels at endpoint as compared to the much higher increase in prolactin secretion that accompanied haloperidol treatment. 3. 3. The weak effects on prolactin as well as the previously reported low incidence of extrapyramidal side effects confirm the profile of remoxipride as a selective dopamine D2 antagonist with preferential effects on the mesolimbic and mesocortical tracts. 4. 4. Male responders to either remoxipride or haloperidol treatment had significantly higher baseline prolactin levels regardless of dose and drug used. In females, there was no difference in baseline prolactin between responders and nonresponders.

Depression, Affect and Negative Symptoms in Schizophrenia

The relationship of depression with affect deficit in schizophrenic patients continues to challenge both the clinician and the researcher. Often there is considerable difficulty in differentiating these two affect states in a reliable and valid fashion. On the observational level, depressed affect often appears somewhat restricted, having lost the full range of the euthymic state. On a subjective level, schizophrenic patients often complain of anhedonia, a defect in pleasure capacity which is shared by patients who are depressed. On the prognostic level, there is a large body of literature that links depressive features in acute schizophrenics to favourable subsequent course (Astrup & Noreik, 1966; Vaillant, 1964). We were, therefore, interested in investigating the relationship of depression with impaired affect and with positive/negative symptoms in young acute schizophrenic patients. We used a systematic multidimensional study of affect impairment among 37 young acute schizophrenic patients in a prospective, longitudinal approach over a 2-year span. In addition to a detailed assessment of the affect profile, including depression, both at baseline and on follow-up, we rated patients clinically for a positive and negative syndrome as well as general psychopathology, and we conducted premorbid and outcome measurements.

Serum dopamine-beta-hydroxylase activity in clinical subtypes of depression.

Serum dopamine-beta-hydroxylase (DBH) activity was determined in male adult psychiatric patients (n = 280) and age-matched male healthy controls (n = 100). Patients included in the study had no history of previous or current exposure to psychoactive drugs and were diagnosed according to Research Diagnostic Criteria. A significant decrease in serum DBH activity was noted in patients with psychotic major depressive disorder (n = 50) as compared with controls. In acute schizophrenics (n = 100), nonpsychotic major depressives (n = 45) and patients with manic disorder (n = 85), mean DBH activity did not differ significantly from the control values.

Multivariate EEG power spectral analysis in acute schizophrenics

The electroencephalogram (EEG) during information processing is influenced by specific changes in brain electrical activity. Based on the theory of disturbed information processing in schizophrenics, we analysed auditory stimulus induced EEG changes by Fast Fourier Transformation. The most important of the significant stimulation-dependent EEG power changes were measured in the 0.5–3.5 Hz and 10–13.5 Hz frequency bands in the left frontoparietal lead. In a multivariate analysis the separation of the subjects examined into acute schizophrenics and normals was incorrect in only 21% of the cases (resubstitution rate); using π-method an error of 31% was estimated.

Normal P300 in acute schizophrenics during a continuous performance test

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Repeated acoustic stimulation of acute schizophrenic patients and the habituation of EEG power changes

Habituation in psychiatric patients to repeated stimuli has typically been described in connection with the measurement of the skin conductance orienting response. Here EEG power spectra of acute schizophrenic patients and normals to 4 trials of an acoustic stimulation were examined for evidence of habituation. In response to stimulation the α EEG reactivity was less distinct in schizophrenics than in normals. This is in agreement with the theory of hypovariability or hyperstability of the EEG in schizophrenics. Signs of habituation in acute schizophrenics were clearer in fast β frequencies of the parietal leads.

Schizophrenic inability to judge facial emotion: A controlled study

The ability of schizophrenics to judge facial emotion was examined using a new test derived to remedy methodological inadequacies in previous studies. The derivation procedure of the test is described. Five groups of 20 subjects each took part: acute schizophrenics, chronic schizophrenics, schizophrenics in remission, in-patients with depressive illness and normal subjects. They were asked to make a dichotomous emotion judgement ('happy' or 'sad') about a set of photographed faces: and then to make a dichotomous non-emotion judgement ('old' or 'young') on a set of photographs chosen from the same original pool to form a task of equal difficulty and discriminating ability. It was predicted, from previous studies, that acute schizophrenics would be specifically impaired on judging emotional expression in faces. Instead, they were found to be impaired on both an emotion and a non-emotion task on photographs of faces when these tasks were matched for difficulty and discriminating ability. They were significantly worse than remitted schizophrenics and normal subjects for both tasks, and for emotion, significantly worse then depressed subjects as well. The findings are considered in the light of current theories of visual processing in schizophrenia and of the neuropsychology of face processing.

Spatiotemporal memory and rate of forgetting in acute schizophrenics.

Some schizophrenics show anomalies in the frontal and temporal lobes. It is uncertain whether the cognitive deficits shown by Type I schizophrenics are caused directly by such anomalies, or by a deficit in the exertion of attentional effort. In this study, 16 acute schizophrenics, who broadly fitted the Type I characterization and their controls were given a battery of cognitive tests. The patients were impaired on effort-demanding tasks such as the Wisconsin Card Sorting Test, a verbal fluency test and the WAIS, which are susceptible in varying degrees to frontal, temporal and parietal lobe lesions. Patients were not disproportionately impaired, however, on a test of temporal memory and another of spatial memory, an impairment pattern that selectively reflects frontal and medial temporal lobe lesions respectively, nor were they impaired on a rate of forgetting task sensitive to medial temporal lobe lesions. These tasks were chosen not only because performance on them is selectively sensitive to frontotemporal lobe lesions, but also because it seems to depend on exerting minimum amounts of attentional effort. It is tentatively concluded that the cognitive deficits shown by Type I schizophrenics are caused by a problem in exerting attentional effort of unknown origin.

Schizophrenia — an emotional hypersensitivity of the right cerebral hemisphere

While modern neuropsychological and electrophysiological studies claim a functional disturbance of the left hemisphere (LH) in schizophrenia, historical clinical and anatomical work rather points to the right hemisphere (RH) as the main site of psychosis. In the light of an interhemispheric functional balance of inhibition and release, LH-dysfunction in schizophrenia could be interpreted as a consequence of an overactive and inhibiting RH. Since the RH is especially activated by emotional stimuli, and exaggerated distractability and sensitivity to emotional stimuli are hallmarks of schizophrenia, we compared the emotional irritability of the RH and LH in 35 acute schizophrenics and 22 matched controls. Using tachistoscopic half-field presentation we found in acute schizophrenics a selective impairment of RH-function with simultaneous improvement of LH-performance induced by emotional distractors. We therefore suggest that a right hemispheric dysfunction and hypersensitivity to emotional material plays an essential catalytic role in acute schizophrenia.