Physiological responsivity to emotional pictures in schizophrenia

Schizophrenic patients are known to experience difficulties in emotional information processing, yet knowledge of their physiological responsivity to emotional stimuli is limited. The purpose of this study was to investigate the physiological reactions of schizophrenic patients to emotional stimuli. We presented pictures selected from the International Affective Picture System (IAPS) to patients and controls, while assessing their subjective evaluations in terms of valence and arousal scores and measuring their responses of heart rate (HR), breathing rate (BR), skin conductance level (SCL) and diastolic (DBP) and systolic blood pressure (SBP). For the analysis of the physiological data, three emotional picture categories were formed: positive (erotic content), negative (physical injuries) and neutral (landscapes). Patients and controls did not differ in their subjective evaluations of the pictures. Also, for both patients and controls, the SCL and DBP responses to positive emotional pictures were larger as compared to negative and neutral pictures. However, the patients did show significantly increased HR responses to the positive emotional pictures as compared to controls, possibly as a result of a decreased parasympathetic activity. Only for the BR response to the positive emotional pictures did we observe significant positive correlations with the PANSS scores. These first data suggest that altered physiological responsivity to emotional pictures in schizophrenia is limited to those with positive emotional content. Further studies will need to refine the dynamics of this stimulus category in relation to clinical state and medication effects.     

Subjective emotional over-arousal to neutral social scenes in paranoid schizophrenia

From the clinical practice and some experimental studies, it is apparent that paranoid schizophrenia patients tend to assign emotional salience to neutral social stimuli. This aberrant cognitive bias has been conceptualized to result from increased emotional arousal, but direct empirical data are scarce. The aim of the present study was to quantify the subjective emotional arousal (SEA) evoked by emotionally non-salient (neutral) compared to emotionally salient (negative) social stimuli in schizophrenia patients and healthy controls. Thirty male inpatients with paranoid schizophrenia psychosis and 30 demographically matched healthy controls rated their level of SEA in response to neutral and negative social scenes from the International Affective Picture System and the Munich Affective Picture System. Schizophrenia patients compared to healthy controls had an increased overall SEA level. This relatively higher SEA was evoked only by the neutral but not by the negative social scenes. To our knowledge, the present study is the first designed to directly demonstrate subjective emotional over-arousal to neutral social scenes in paranoid schizophrenia. This finding might explain previous clinical and experimental data and could be viewed as the missing link between the primary neurobiological and secondary psychological mechanisms of paranoid psychotic-symptom formation. Furthermore, despite being very short and easy to perform, the task we used appeared to be sensitive enough to reveal emotional dysregulation, in terms of emotional disinhibition/hyperactivation in paranoid schizophrenia patients. Thus, it could have further research and clinical applications, including as a neurobehavioral probe for imaging studies.     

The relationship of paranoid states to schizophrenia

The author interviewed relatives of 32 paranoid patients, 32 matched depressed patients, and 15 schizophrenic patients regarding family history. Two (1.3%) of the relatives of paranoid patients and one (0.6%) of the relatives of depressed patients had possible paranoid states. Significantly more relatives of schizophrenic patients than relatives of paranoid or depressed patients had schizophrenia, but the rates were similar among relatives of paranoid and depressed patients. The author concludes that there is little evidence of familial occurrence of paranoid states and no evidence that paranoid states are familially related to schizophrenia.     

Dimensions of psychopathology in paranoid schizophrenia

Recently, there has been a great deal of interest in understanding the latent organisation of the phenomenology of schizophrenia through examination of the fit of dimensional models to observed symptoms date. A group of 66 DSM-IV paranoid schizophrenic in-patients were assessed three times using the SAPS, SANS, BPRS and PAS. The interrelations between individual symptoms of each scale were examined by means of principal component analysis. The results of factor analysis of the findings from SANS and SAPS confirm the three-factor model, composed of a negative, disorganisation and psychotic factor. Extending the range of symptomatology using BPRS resulted in a five-factor model, composed of the following factors: paranoid, negative, affective, cognitive and disorganised behaviour. In view of the findings based on Strauss’ work (1974) the PAS has been added to the SANS, SAPS and BPRS, whose results were examined by factor analysis. The findings indicate that it is possible to consider a six-factor model, composed of the following dimensions: paranoid, negative, affective, cognitive, disorganised behaviour and premorbid social adjustment deficits. The number of factors that best reflect the structure of the symptomatology of paranoid schizophrenia depends on the range of the symptoms under study, i.e., on the type of scales. It follows from our study that six-factor model appears to be the most suitable and clear model in rendering the multidimensionality of paranoid schizophrenia phenomenology. Received: 19 March 1998 / Accepted: 9 September 1999     

The Capgras syndrome in paranoid schizophrenia.

Capgras syndrome is characterized by a delusion of impostors who are thought to be physically similar but psychologically distinct from the misidentified person. This syndrome is generally thought to be relatively rare. Most of our knowledge about Capgras syndrome derives from single case studies and small series of cases usually from diagnostically heterogeneous groups. In this article, a series of 31 patients suffering from both paranoid schizophrenia and Capgras syndrome is described. Issues pertaining to the phenomenology of Capgras syndrome, the possible relation between Capgras syndrome and other delusional misidentification syndromes, and a neurobiological hypothesis aimed at explaining Capgras syndrome are discussed.     

Hemispheric functioning in paranoid and nonparanoid schizophrenia

Letter-naming and dot enumeration tasks, designed to elicit left and right hemisphere functioning, respectively, were presented tachistoscopically to paranoid and nonparanoid schizophrenics, nonschizophrenic psychiatry controls, and normal subjects. Types of information-processing used by paranoid and nonparanoid schizophrenics were also examined. All groups identified letters with greater accuracy with left hemisphere presentation. Group differences in the letter task disappeared once education was controlled. No hemisphere effect was found for dot enumeration but group differences emerged. As predicted, paranoids and controls processed the dots serially and hence decreased in accuracy over frame size. Nonparanoids processed in an automatic mode, revealing the same degree of accuracy over all dot sizes. The poorer performance of the nonparanoids in dot enumeration is discussed in terms of the task requiring bilateral processing and the nonparanoids' failure to integrate the processing of left and right hemispheres.     

Spinocerebellar ataxia-10 with paranoid schizophrenia

Spino-cerebellar ataxia type 10 (SCA10) is an autosomal dominant disorder that is characterized by cerebellar ataxia, seizures and nystagmus with a fragmented pursuit. Schizophrenia has been reported with SCAs 1 and 2 yet in SCA 10, psychiatric manifestations are uncommon. We report a Hispanic family involving a father and his four children with SCA10 genetic mutation. Two of his children, a 20-year-old female and a 23-year-old male, presented with gradually progressive spino-cerebellar ataxia and paranoid schizophrenia. Neurological examination revealed ocular dysmetria, dysdiadokinesia, impaired finger-to-nose exam, gait ataxia and hyperreflexia in both the cases. Additionally, they had a history of psychosis with destructive behavior, depression and paranoid delusions with auditory hallucinations. Serology and CSF studies were unremarkable and MRI brain revealed cerebellar volume loss. Ultimately, a test for ATAXIN-10 mutation was positive thus confirming the diagnosis of SCA10 in father and his four children. We now endeavor to investigate the association between schizophrenia and SCA10.     

Cannabis psychosis and paranoid schizophrenia.

The initial clinical symptoms of 25 consecutive cases of cannabis psychosis of the paranoid type and 25 consecutive cases of paranoid schizophrenia were studied and compared, in order to delineate features that would enable a differentiation of the two conditions. It was observed that the patients with cannabis psychosis substantially differed in terms of behavioral manifestations. Most of these patients were violent and panicky and demonstrated bizzare behavior, but they possessed some insight into the nature of their illness. Schizophrenic patients manifested these disturbances and characteristics less frequently. Subjects with cannabis psychosis showed rapid ideation and flight of ideas, whereas the characteristic schizophrenic thought-disorder was found mostly in schizophrenic patients.     

CSF phenylacetic acid and hostility in paranoid schizophrenia

Lumbar cerebrospinal fluid concentrations of phenylacetic acid were significantly elevated in paranoid vs. nonparanoid schizophrenics. Further, phenylacetic acid concentrations were correlated with hostility. These results are consistent with the hypothesis that phenylethylamine, the proposed precursor of phenylacetic acid, plays a role in schizophrenia.     

Psychopathological characteristics in alcohol hallucinosis and paranoid schizophrenia

In a retrospective study psychopathology, psychiatric family history and demographic data were studied in 53 patients with alcohol hallucinosis and an age- and sex-matched control group of 53 patients with paranoid schizophrenia who had been treated at the Psychiatric Hospital of the University of Munich between 1979 and 1986. The psychopathology was assessed by the AMDP system. The paranoid-hallucinatory symptoms in both conditions were very similar; verbal hallucinations and delusions of reference were most common in both groups. Disorders of ego were found in 87% of the schizophrenics, but only 30% of the alcoholic patients (P less than 0.001). Schizophrenics developed psychosis at a younger age than alcoholics and seemed to have poorer outcome. Patients with alcohol hallucinosis had more relatives with an alcohol history (P less than 0.001), and schizophrenics more relatives with schizophrenic psychosis (P less than 0.001).     

Apparent motion perception in patients with paranoid schizophrenia

Impaired perceptual inference has been suggested to be at the core of positive symptoms in schizophrenia. Apparent motion (AM) is a visual illusion in which perceptual inference gives rise to the experience of a single object moving back and forth when two spatially separated objects are flashed in alternation. Here, we investigated the strength of AM perception in patients with paranoid schizophrenia. Patients were less susceptible to the illusion as indicated by a lower probability of motion perception at the individual’s optimal presentation frequency for AM. In addition, the probability of AM perception was inversely related to delusional conviction in the patient group. These results suggest that schizophrenia may be associated with a reduced susceptibility to visual phenomena that commonly rely on perceptual inference.     

Functional disintegration in paranoid schizophrenia using resting-state fMRI

Functional disintegration has been observed in schizophrenia during task performance. We sought to investigate functional disintegration during rest because an intrinsic functional brain organization, including both "task-negative" (i.e., "default mode") and "task-positive" networks, has been suggested to play an important role in integrating ongoing information processing. Additionally, the brain regions that are involved in the intrinsic organization are believed to be abnormal in schizophrenia. Patients with paranoid schizophrenia (N=18) and healthy volunteers (N=18) underwent a resting-state fMRI scan. Functional connectivity analysis was used to identify the connectivity between each pair of brain regions within this intrinsic organization, and differences were examined in patients versus healthy volunteers. Compared to healthy volunteers, patients showed significant differences in connectivity within networks and between networks, most notably in the connectivities associated with the bilateral dorsal medial prefrontal cortex, the lateral parietal region, the inferior temporal gyrus of the "task-negative" network and with the right dorsolateral prefrontal cortex and the right dorsal premotor cortex of the "task-positive" network. These results suggested that the interregional functional connectivities in the intrinsic organization are altered in patients with paranoid schizophrenia. These abnormalities could be the source of abnormalities in the coordination of and competition between information processing activities in the resting brain of paranoid patients.