Role of Dopamine D2 Receptors in Human Reinforcement Learning

Influential neurocomputational models emphasize dopamine (DA) as an electrophysiological and neurochemical correlate of reinforcement learning. However, evidence of a specific causal role of DA receptors in learning has been less forthcoming, especially in humans. Here we combine, in a between-subjects design, administration of a high dose of the selective DA D2/3-receptor antagonist sulpiride with genetic analysis of the DA D2 receptor in a behavioral study of reinforcement learning in a sample of 78 healthy male volunteers. In contrast to predictions of prevailing models emphasizing DA's pivotal role in learning via prediction errors, we found that sulpiride did not disrupt learning, but rather induced profound impairments in choice performance. The disruption was selective for stimuli indicating reward, while loss avoidance performance was unaffected. Effects were driven by volunteers with higher serum levels of the drug, and in those with genetically-determined lower density of striatal DA D2 receptors. This is the clearest demonstration to date for a causal modulatory role of the DA D2 receptor in choice performance that might be distinct from learning. Our findings challenge current reward prediction error models of reinforcement learning, and suggest that classical animal models emphasizing a role of postsynaptic DA D2 receptors in motivational aspects of reinforcement learning may apply to humans as well.Neuropsychopharmacology accepted article peview online, 09 April 2014; doi:10.1038/npp.2014.84

Evaluating care pathways for community psychiatry in England:a qualitative study

Objectives  In view of forthcoming ‘payment by results’ (PbR) for mental health, increasing number of National Health Service (NHS) Trusts are reorganizing their community services for working age adults to create care pathways. However, research base for the care pathways model in mental health is limited. Our NHS Foundation Trust was one of the first to introduce care pathways for community psychiatry in the UK. We have carried out a qualitative study to evaluate how this model works out in practice, including its impact on quality of patient care, mental health professionals and primary care. Methods  We interviewed doctors, multidisciplinary staff and Trusts managers (19 in total). Transcripts of recorded interviews were coded and analysed thematically using a grounded theory approach. Results  Overall, despite teething problems, working in pathways was generally seen as a positive change. It led to more focused interventions being offered, and practitioners being held to account over clear standards of care. It is more cost‐effective and allows for active case management and clear clinical leadership. It is recovery focused and encourages social inclusion. The arbitrary time frame, strict criteria and thresholds for different teams can create issues. Improved communication, flexible and patient‐centred approach, staff supervision, and increasing support to primary care were felt to be central to this model working efficiently and effectively. Conclusions  Introduction of care pathways is an important step towards effective implementation of PbR for mental health. Our study would inform future research into care pathways, facilitate organizational learning and help to improve effectiveness of services

Factors in Psychiatric Admissions: Before and During the Covid-19 Pandemic.

OBJECTIVE: The COVID-19 pandemic has impacted community mental health, but the effect on psychiatric admissions is unknown. We investigated factors contributing to acute psychiatric admissions, and whether this changed during the first UK lockdown. METHOD: A retrospective case-note review study with an exploratory mixed-methods design to examine factors for psychiatric admissions following the first UK 2020 lockdown compared to the same time periods in 2019 and 2018. RESULTS: Themes of psychopathology, risk, social stressors, community treatment issues, and physical health concerns were generated. The mean number of codes per case was 6.19 (s . d. = 2.43), with a mean number of categories per case of 3.73, (s. d. = 0.98). Changes in routines and isolation were common factors in the study year; accommodation and substance abuse were more prominent in the control year. Relationship stressors featured strongly in both groups. There were significantly more women (χ2(1, N = 98) = 20.80, p < 0.00001) and older adults (χ2(1, N = 98) = 8.61, p = 0.0033) in the study group than the control. Single people, compared to those in a relationship (χ2(1, N = 45) = 4.46, p = 0.035), and people with affective disorders compared to psychotic disorders ((χ2(1, N = 28) = 5.19, p = 0.023), were more likely to have a COVID-19 related admission factor. CONCLUSIONS: Early stages of the COVID-19 pandemic amplified pre-existing psychosocial vulnerabilities with a disproportionate psychiatric admissions impact on the mental health of women, older adults and those with affective disorders