Search

Past studies have demonstrated that the Brief Negative Symptom Scale (BNSS) has excellent psychometric properties in patients with schizophrenia. In the current study, we extended this literature by examining psychometric properties of the BNSS in outpatients diagnosed with bipolar disorder (n=46), outpatients with schizophrenia (n=50), and healthy controls (n=27). Participants completed neuropsychological testing and a clinical interview designed to assess negative, positive, disorganized, mood, and general psychiatric symptoms. Results indicated differences among the 3 groups in the severity of all BNSS items, with SZ and BD scoring higher than CN; however, SZ and BD only differed on blunted affect and alogia items, not anhedonia, avolition, or asociality. BD patients with a history of psychosis did not differ from those without a history of psychosis on negative symptom severity. The BNSS had excellent internal consistency in SZ, BD, and CN groups. Good convergent and discriminant validity was apparent in SZ and BD groups, as indicated by relationships between the BNSS and other clinical rating scales. These findings support the validity of the BNSS in broadly defined serious mental illness populations.

The present study sought to test whether perceptual segregation of concurrently played sounds is impaired in schizophrenia (SZ), whether impairment in sound segregation predicts difficulties with a real-world speech-in-noise task, and whether auditory-specific or general cognitive processing accounts for sound segregation problems. Participants with SZ and healthy controls (HCs) performed a mistuned harmonic segregation task during recording of event-related potentials (ERPs). Participants also performed a brief speech-in-noise task. Participants with SZ showed deficits in the mistuned harmonic task and the speech-in-noise task, compared to HCs. No deficit in SZ was found in the ERP component related to mistuned harmonic segregation at around 150 ms (the object-related negativity or ORN), but instead showed a deficit in processing at around 400 ms (the P4 response). However, regression analyses showed that indexes of education level and general cognitive function were the best predictors of sound segregation difficulties, suggesting non-auditory specific causes of concurrent sound segregation problems in SZ.

Objectives Auditory perception deficits have been identified in schizophrenia (SZ) and linked to dysfunction in the auditory cortex. Given that psychotic symptoms, including auditory hallucinations, are also seen in bipolar disorder (BD), it may be that individuals with BD who also exhibit psychotic symptoms demonstrate a similar impairment in auditory perception. Methods Fifty individuals with SZ, 30 individuals with bipolar I disorder with a history of psychosis (BD+), 28 individuals with bipolar I disorder with no history of psychotic features (BD−), and 29 normal controls (NC) were administered a tone discrimination task and an emotion recognition task. Results Mixed-model analyses of covariance with planned comparisons indicated that individuals with BD+ performed at a level that was intermediate between those with BD− and those with SZ on the more difficult condition of the tone discrimination task and on the auditory condition of the emotion recognition task. There were no differences between the BD+ and BD− groups on the visual or auditory–visual affect recognition conditions. Regression analyses indicated that performance on the tone discrimination task predicted performance on all conditions of the emotion recognition task. Auditory hallucinations in BD+ were not related to performance on either task. Conclusions Our findings suggested that, although deficits in frequency discrimination and emotion recognition are more severe in SZ, these impairments extend to BD+. Although our results did not support the idea that auditory hallucinations may be related to these deficits, they indicated that basic auditory deficits may be a marker for psychosis, regardless of SZ or BD diagnosis.

Well-documented auditory processing deficits such as impaired frequency discrimination and reduced suppression of auditory brain responses in schizophrenia (SZ) may contribute to abnormal auditory functioning in everyday life. Lateral suppression of non-stimulated neurons by stimulated neurons has not been extensively assessed in SZ and likely plays an important role in precise encoding of sounds. Therefore, this study evaluated whether lateral suppression of activity in auditory cortex is impaired in SZ.SZ participants and control participants watched a silent movie with subtitles while listening to trials composed of a 0.5s control stimulus (CS), a 3s filtered masking noise (FN), and a 0.5s test stimulus (TS). The CS and TS were identical on each trial and had energy corresponding to the high energy (recurrent suppression) or low energy (lateral suppression) portions of the FN. Event-related potentials were recorded and suppression was measured as the amplitude change between CS and TS.Peak amplitudes of the auditory P2 component (160-260ms) showed reduced lateral but not recurrent suppression in SZ participants.Reduced lateral suppression in SZ participants may lead to overlap of neuronal populations representing different auditory stimuli. Such imprecise neural representations may contribute to the difficulties SZ participants have in discriminating complex stimuli in everyday life.

While it is well-established that patients with schizophrenia and bipolar disorder exhibit deficits in social cognition, few studies have separately examined bipolar disorder with and without psychotic features. The current study addressed this gap by comparing patients with bipolar disorder with (BD+) and without (BD-) psychotic features, patients with schizophrenia (SZ), and healthy controls (NC) across social cognitive measures. Principal factor analysis on five social cognition tasks extracted a two-factor structure comprised of social/emotional processing and theory of mind. Factor scores were compared among the four groups. Results identified differential patterns of impairment between the BD+ and BD- group on the social/emotional processing factor while all clinical groups performed poorer than controls on the theory of mind factor. This provides evidence that a history of psychosis should be taken into account while evaluating social cognition in patients with bipolar disorder and also raises hypotheses about the relationship between social cognition and psychosis.

Emotion perception deficits are a well-established feature of schizophrenia (SZ). Individuals with SZ have difficulty labeling emotional stimuli across auditory, visual, and audio-visual modalities and also misattribute threat towards neutral stimuli. The relationship between a history of psychosis and similar abnormalities in bipolar disorder (BD) is less clear. The current study set out to examine emotion perception across sensory modalities in a sample of 24 stabilized individuals meeting criteria for SZ, 24 remitted individuals meeting criteria for BD with psychotic features, 24 remitted individuals meeting criteria for BD without psychotic features, and 24 healthy controls. Results indicated that the bipolar with psychotic features group had intermediary performance between the SZ group and the other two groups for auditory, visual, and audio-visual items, with particularly poor performance in identifying angry stimuli. The SZ group misattributed neutral stimuli as negative when they were in visual format, but as positive when they were in auditory or audio-visual formats. The bipolar with psychotic features group had a trend towards misattributing more neutral visual stimuli as negative. These findings indicate that emotion perception deficits are present in BD with psychotic features and comparatively spared in BD without psychotic features, and that a similar bias of misattributing negative emotions to neutral visual stimuli may be present across diagnostic boundaries.