ABSTRACT
Aggression and violence are common day to day problems in psychiatric settings. However, the optimal means of assessing that risk remains unclear. In the context of that uncertainty many tools have evolved, among which the HCR-20 is one of the most globally accepted, though many questions remain about its performance, how and when it should be deployed and how it can be most effectively used. In this 12 month follow up study of 210 forensic psychiatric inpatients with a diagnosis of a schizophrenia spectrum disorder we explored these issues. We found that the performance of the HCR-20v3, especially its Total score, performed well up to 6 months after it was rated but its performance deteriorated after that. Repeating the HCR-20v3 at 6 months stabilised the risk assessment and led to improved performance in the second months over and above the first rating. The HCR-20v3 was good at identifying those subjects at low risk of violence over 6 months of follow up in a forensic inpatient setting. The real-world implications of this study are that the HCR-20v3 is an effective means of identifying patient at low risk of violence, but it should be reassessed every 6 months.
ABSTRACT
BACKGROUND: The current study was designed to test the hypothesis that motivational deficits in schizophrenia (SZ) are tied to a reduced ability to differentially signal gains and instances of loss-avoidance in the brain, leading to reduced ability to form adaptive representations of expected value. METHODS: We administered a reinforcement learning paradigm to 27 medicated SZ patients and 27 control subjects in which participants learned three probabilistic discriminations. In regions of interest in reward networks identified a priori, we examined contrasts between trial types with different expected values (e.g., expected gain-nonmonetary) and between outcomes with the same prediction error valence but different experienced values (e.g., gain-loss-avoidance outcome, miss-loss outcome). RESULTS: Both whole-brain and region of interest analyses revealed that SZ patients showed reduced differentiation between gain and loss-avoidance outcomes in the dorsal anterior cingulate cortex and bilateral anterior insula. That is, SZ patients showed reduced contrasts between positive prediction errors of different objective values in these areas. In addition, we observed significant correlations between gain-loss-avoidance outcome contrasts in the ventral striatum and ratings for avolition/anhedonia and between expected gain-nonmonetary contrasts in the ventral striatum and ventromedial prefrontal cortex. CONCLUSIONS: These results provide further evidence for intact prediction error signaling in medicated SZ patients, especially with regard to loss-avoidance. By contrast, components of frontostriatal circuits appear to show reduced sensitivity to the absolute valence of expected and experienced outcomes, suggesting a mechanism by which motivational deficits may emerge.
