Using Drift Diffusion and RL Models to Disentangle Effects of Depression On Decision-Making vs. Learning in the Probabilistic Reward Task.

The Probabilistic Reward Task (PRT) is widely used to investigate the impact of Major Depressive Disorder (MDD) on reinforcement learning (RL), and recent studies have used it to provide insight into decision-making mechanisms affected by MDD. The current project used PRT data from unmedicated, treatment-seeking adults with MDD to extend these efforts by: (1) providing a more detailed analysis of standard PRT metrics-response bias and discriminability-to better understand how the task is performed; (2) analyzing the data with two computational models and providing psychometric analyses of both; and (3) determining whether response bias, discriminability, or model parameters predicted responses to treatment with placebo or the atypical antidepressant bupropion. Analysis of standard metrics replicated recent work by demonstrating a dependency between response bias and response time (RT), and by showing that reward totals in the PRT are governed by discriminability. Behavior was well-captured by the Hierarchical Drift Diffusion Model (HDDM), which models decision-making processes; the HDDM showed excellent internal consistency and acceptable retest reliability. A separate "belief" model reproduced the evolution of response bias over time better than the HDDM, but its psychometric properties were weaker. Finally, the predictive utility of the PRT was limited by small samples; nevertheless, depressed adults who responded to bupropion showed larger pre-treatment starting point biases in the HDDM than non-responders, indicating greater sensitivity to the PRT's asymmetric reinforcement contingencies. Together, these findings enhance our understanding of reward and decision-making mechanisms that are implicated in MDD and probed by the PRT.

Mapping the scientific literature on obstetrical and perinatal health among sexual and gender minoritised (SGM) childbearing people and their infants: a scoping review protocol.

INTRODUCTION: Sexual and gender minoritised (SGM) populations are disproportionately impacted by multilevel risk factors for obstetrical and perinatal outcomes, including structural (eg, stigma, discrimination, access to care) and individual risk factors (eg, partner violence, poor mental health, substance use). Emerging evidence shows SGM childbearing people have worse obstetrical outcomes and their infants have worse perinatal outcomes, when compared with their cisgender and heterosexual counterparts; this emerging evidence necessitates a comprehensive examination of existing literature on obstetrical and perinatal health among SGM people. The goal of this scoping review is to comprehensively map the extent, range and nature of scientific literature on obstetrical and perinatal physical health outcomes among SGM populations and their infants. We aim to summarise findings from existing literature, potentially informing clinical guidelines on perinatal care, as well as highlighting knowledge gaps and providing directions for future research. METHODS AND ANALYSIS: We will follow the Joanna Briggs Institute (JBI) scoping review framework and report findings according to the PRISMA Extension for Scoping Reviews (PRISMA-ScR) guidelines. We will conduct a broad systematic search in Medline/PubMed, Embase, CINAHL and Web of Science Core Collection. Eligible studies will include peer-reviewed, empirical, English-language publications pertaining to obstetrical and perinatal physical health outcomes of SGM people or their infants. No temporal or geographical limitations will be applied to the search. Studies conducted in all settings will be considered. Records will be managed, screened and extracted by two independent reviewers. Study characteristics, key findings and research gaps will be presented in tables and summarised narratively. ETHICS AND DISSEMINATION: Ethical approval is not required as primary data will not be collected. The findings of this scoping review will be disseminated through a peer-reviewed journal and conference presentations. PROTOCOL REGISTRATION: Open Science Framework https://osf.io/6fg4a/.

Neurobiological Mechanisms Of Depression Following Traumatic Brain Injury.

OBJECTIVE: Depression is among the most pervasive and debilitating neuropsychiatric sequelae experienced by patients following a traumatic brain injury (TBI). While the individual mechanisms underlying depression and TBI have been widely studied, the neurobiological bases of depression after TBI remain largely unknown. This article highlights the potential mechanisms of action implicated in depression after TBI. RESULTS: We review putative mechanisms of action including neuroinflammation, neuroendocrine dysregulation, metabolic abnormalities, and neurotransmitter and circuitry dysfunction. We also identify the current limitations in the field and propose directions for future research. CONCLUSION: An improved understanding of the underlying mechanisms will aid the development of precision-guided and personalized treatments for patients suffering from depression after TBI.

A multi-pronged investigation of option generation using depression, PET and modafinil.

Option generation is a critical process in decision making, but previous studies have largely focused on choices between options given by a researcher. Consequently, how we self-generate options for behaviour remain poorly understood. Here, we investigated option generation in major depressive disorder and how dopamine might modulate this process, as well as the effects of modafinil (a putative cognitive enhancer) on option generation in healthy individuals. We first compared differences in self-generated options between healthy non-depressed adults [n = 44, age = 26.3 years (SD 5.9)] and patients with major depressive disorder [n = 54, age = 24.8 years (SD 7.4)]. In the second study, a subset of depressed individuals [n = 22, age = 25.6 years (SD 7.8)] underwent PET scans with 11C-raclopride to examine the relationships between dopamine D2/D3 receptor availability and individual differences in option generation. Finally, a randomized, double-blind, placebo-controlled, three-way crossover study of modafinil (100 mg and 200 mg), was conducted in an independent sample of healthy people [n = 19, age = 23.2 years (SD 4.8)] to compare option generation under different doses of this drug. The first study revealed that patients with major depressive disorder produced significantly fewer options [t(96) = 2.68, P = 0.009, Cohen's d = 0.54], albeit with greater uniqueness [t(96) = -2.54, P = 0.01, Cohen's d = 0.52], on the option generation task compared to healthy controls. In the second study, we found that 11C-raclopride binding potential in the putamen was negatively correlated with fluency (r = -0.69, P = 0.001) but positively associated with uniqueness (r = 0.59, P = 0.007). Hence, depressed individuals with higher densities of unoccupied putamen D2/D3 receptors in the putamen generated fewer but more unique options, whereas patients with lower D2/D3 receptor availability were likely to produce a larger number of similar options. Finally, healthy participants were less unique [F(2,36) = 3.32, P = 0.048, partial η2 = 0.16] and diverse [F(2,36) = 4.31, P = 0.021, partial η2 = 0.19] after taking 200 mg versus 100 mg and 0 mg of modafinil, while fluency increased linearly with dosage at a trend level [F(1,18) = 4.11, P = 0.058, partial η2 = 0.19]. Our results show, for the first time, that option generation is affected in clinical depression and that dopaminergic activity in the putamen of patients with major depressive disorder may play a key role in the self-generation of options. Modafinil was also found to influence option generation in healthy people by reducing the creativity of options produced.

Moving from Cultural Competence to Cultural Humility in Psychiatric Education.

Given the significant, persistent health care inequities encountered by minority populations, health care organizations and training programs have sought to incorporate cultural competency training initiatives. However, the variety of pedagogical models demonstrate the current lack of a uniform standardized curriculum. Limitations of knowledge-based cultural competence initiatives have resulted in a shift toward attitude- and behavior-based "cultural humility." Cultural humility, the ability to maintain an interpersonal stance that is open in relation to aspects of cultural identity that are most important to the patient, expands on cultural competence, which is essential to improving patient care in mental health care settings.

Don't Ditch the Laptop Just Yet: A Direct Replication of Mueller and Oppenheimer's (2014) Study 1 Plus Mini Meta-Analyses Across Similar Studies.

In this direct replication of Mueller and Oppenheimer's (2014) Study 1, participants watched a lecture while taking notes with a laptop (n = 74) or longhand (n = 68). After a brief distraction and without the opportunity to study, they took a quiz. As in the original study, laptop participants took notes containing more words spoken verbatim by the lecturer and more words overall than did longhand participants. However, laptop participants did not perform better than longhand participants on the quiz. Exploratory meta-analyses of eight similar studies echoed this pattern. In addition, in both the original study and our replication, higher word count was associated with better quiz performance, and higher verbatim overlap was associated with worse quiz performance, but the latter finding was not robust in our replication. Overall, results do not support the idea that longhand note taking improves immediate learning via better encoding of information.