Flash electroretinography (fERG) has been used to identify anomalies in retinal cell function in schizophrenia. Several consistent findings have now emerged, but several potentially important parameters have not yet been investigated. In this study, we recorded light- (photopic) and dark-adapted (scotopic) fERG data from 25 schizophrenia patients and 25 healthy control subjects to (1) determine if past key findings on abnormal photoreceptor and bipolar cell signaling could be replicated; (2) for the first time, examine retinal ganglion cell functioning using the photopic negative response of the fERG; (3) also for the first time, determine responsiveness of schizophrenia patients to a flickering stimulus, as an additional method to isolate cone photoreceptor function; and (4) determine if schizophrenia-related changes in the fERG could be detected using a portable hand-held ERG device. In both photopic and scotopic conditions, schizophrenia patients demonstrated weakened photoreceptor and bipolar cell activations that were most pronounced in response to the most intense stimuli. A reduced cone response to a flicker stimulus and attenuation in ganglion cell activity were also observed in the schizophrenia group. In general, groups did not differ in implicit time of retinal cell responses. These findings (1) replicate and extend prior studies demonstrating reduced photoreceptor (both rod and cone) and bipolar cell functioning in schizophrenia; (2) indicate that retinal ganglion function abnormality can also be detected using fERG; and (3) indicate that these anomalies can be detected using a portable testing device, thereby opening up possibilities for more routine administration of ERG testing. (PsycINFO Database Record

Published findings on the relationship between schizophrenia and violence have been mixed, due to differences in study design and quality. In this review, we address the issue with an emphasis on characterizing who is most likely to be violent and when. We conclude that: (1) individuals with schizophrenia are at an increased risk for violence due to specific psychotic symptoms; (2) this risk is increased by brain abnormalities, psychiatric comorbidities, and demographic factors that are not specific to schizophrenia; (3) the majority of violent offenses committed by people with schizophrenia are indistinguishable from offenses committed by others; and (4) despite our knowledge of factors related to increased violence risk and the existence of effective treatments to mitigate this risk, valid risk assessment instruments for this population are lacking, and treatment strategies are rarely employed at any level of psychiatric care. In short, while most people with schizophrenia are not violent and violence committed by people with this condition accounts for only a small percentage of overall violent crime, there is nevertheless a significantly increased risk for violence among subgroups in this population. This has implications for people living with people with schizophrenia, mental health professionals, administrators of psychiatric care facilities, law enforcement personnel, the court system, and policymakers.

Schizophrenia patients with more positive symptoms are less susceptible to depth inversion illusions (DIIs) in which concave objects appear as convex. It remains unclear, however, the extent to which this perceptual advantage uniquely characterizes the schizophrenia phenotype. To address the foregoing, we compared 30 bipolar disorder patients to a previously published sample of healthy controls (N = 25) and schizophrenia patients (N = 30). The task in all cases was to judge the apparent convexity of physically concave faces and scenes. Half of the concave objects were painted with realistic texture to enhance the convexity illusion and the remaining objects were untextured to reduce the illusion. Subjects viewed objects stereoscopically or via monocular motion parallax depth cues. For each group, DIIs were stronger with texture than without, and weaker with stereoscopic information than without, indicating a uniformly normal response to stimulus alterations across groups. Bipolar patients experienced DIIs more frequently than schizophrenia patients but as commonly as controls, irrespective of the face/scene category, texture, or viewing condition (motion/stereo). More severe positive and disorganized symptoms predicted reduced DIIs for schizophrenia patients and across all patients. These results suggest that people with schizophrenia, but not bipolar disorder, more accurately perceive object depth structure. Psychotic symptoms—or their accompanying neural dysfunction—may primarily drive the effect presumably through eroding the visual system’s generalized tendency to construe unusual or ambiguous surfaces as convex. Because such symptoms are by definition more common in schizophrenia, DIIs are at once state-sensitive and diagnostically specific, offering a potential biomarker for the presence of acute psychosis.

Research has consistently demonstrated that people diagnosed with serious mental illness (SMI) are at increased risk for violent ideation and behavior (VIB) and that this is especially the case for SMI patients with comorbid substance use disorders (SUD). Despite this, what is still largely unknown is the relative prevalence of VIB across diagnostic categories, whether the rates of VIB in SMI groups exceed the rates observed in people with SUD only, and which demographic factors increase the likelihood of VIB under different circumstances for people with SMI. To address these questions, we analyzed the intake records of 63,572 patients diagnosed with SMIs (i.e., schizoaffective disorder, schizophrenia, bipolar disorder, and unipolar depression), substance use disorders, and non-SMI psychiatric disorders. Raw prevalence rates for a combined metric of VIB were established and compared for each group, and a series of logistic regression analyses were performed to estimate how various demographic factors influenced the likelihood of VIB endorsement in each study group. Our results revealed that (a) patients with SMI conditions had higher rates of VIB than both patients with non-SMI psychopathology and those with substance use disorders only; (b) patients with SMI and comorbid substance use pathology were responsible for the majority of VIB within each SMI condition; and (c) men with SMI conditions had higher prevalence rates of VIB than females. In addition, we found that for every SMI diagnosis, comorbid substance use disorders and younger age were related to greater risk for VIB, and where race and gender were found to significantly alter the likelihood of VIB endorsement, African American status and female gender were independently related to greater risk. The implications of these findings and directions for future research are discussed.

Contour integration is a fundamental visual process that recovers object structure by representing spatially separated edge elements as a continuous contour or shape boundary. Clinically stable persons with schizophrenia have repeatedly been shown to be impaired at contour integration but it is unclear whether this process varies with clinical state or whether it arises as early as the first episode of psychosis. To consider these issues, we administered a contour integration test to persons with chronic schizophrenia and to those with a first episode of psychosis. The test was administered twice—once at admission to short term psychiatric hospitalization and once again at discharge. A well-matched healthy control group was also tested across the same time points. We found that contour integration performance improved to the same degree in all groups over time, indicating that there were no recovery effects over and above normal practice effects. Moreover, the schizophrenia group demonstrated poorer contour integration than the control group and the first episode group exhibited intermediate performance that could not be distinguished from the other groups. These results suggest that contour integration ability does not vary as a function of short-term changes in clinical state, and that it may become further impaired with an increased number of psychotic episodes.