Police Interactions, Perceived Respect, and Longitudinal Changes in Depression in African Americans

Introduction: We examined police exchanges' and feelings of discrimination's impact on changes in adolescent depression symptoms. Relative to other races, police speak more disrespectfully to African Americans and often exert unnecessary force. We investigated the impact of these exchanges on depression. Methods: Adolescent Health Study data were analyzed. Latent growth curve modeling with mediation illustrated relationships between police exchanges, perceived discrimination, and depression changes. Results: African American adolescents had significantly higher levels of initial depression than other racial/ethnic identity groups. For African Americans, police exchanges predicted depression changes. Perceived respect predicted levels and changes of depression for both groups, but mediated the relationship between police exchanges and depression changes only in the “other” racial/ethnic identity group. Discussion: Police stoppings impacted depression changes for African Americans independent of perceived respect. Findings highlight a potentially unique relationship between depression and police exchanges among African Americans. Future studies may investigate roles of individual differences.

Seismic sedimentary characteristics and filling structure of the Upper Triassic Yanchang Formation, Ordos Basin, China

Following the analysis of cores, outcrops, well log, and seismic sections, we have studied the seismic reflection configuration and depositional history of the hydrocarbon-rich Yanchang Formation in the Ordos Basin. We divided the seismic reflection configurations into five types: subparallel reflection, parallel reflection, tangential progradational reflection, shingled progradational reflection, and chaotic reflection. Based on our study results, we concluded that the slopes exhibit differences in the different regions of the Ordos Basin during the sedimentary period of the Yanchang Formation: The slope with the largest gradient of approximately 10°–20° occurred in the southwestern basin, followed by the northwestern basin (with a slope of approximately 1.6°–3.3°), but the slope was relatively gentle in the northeastern basin (approximately 0.8°–1.2°). We also found that the paleocurrent direction of the basin mainly includes two directions: The paleocurrent direction of the southwest region is 186°–259°, which indicates the provenance came from the southwestern region, whereas the paleocurrent direction of the northeast region is 10°–79°, which indicates that the provenance came from the northeastern region. In addition, the Ordos Basin was under isostatic subsidence as a whole during this period, and its sedimentary infilling evolution underwent five stages: the initial depression, intense depression, progradational filling, uplifting and denudation, as well as shrinking and extinction stages, just corresponding with the Chang 10-Chang 9, the Chang 8-Chang 7, the Chang 6-Chang 4+5, the Chang 3-Chang 2, and the Chang 1 depositional age, respectively.

Predicting responses to inhibitory synaptic input in substantia nigra pars reticulata neurons

The changes in firing probability produced by a synaptic input are usually visualized using the poststimulus time histogram (PSTH). It would be useful if postsynaptic firing patterns could be predicted from patterns of afferent synaptic activation, but attempts to predict the PSTH from synaptic potential waveforms using reasoning based on voltage trajectory and spike threshold have not been successful, especially for inhibitory inputs. We measured PSTHs for substantia nigra pars reticulata (SNr) neurons inhibited by optogenetic stimulation of striato-nigral inputs or by matching artificial inhibitory conductances applied by dynamic clamp. The PSTH was predicted by a model based on each SNr cell’s phase-resetting curve (PRC). Optogenetic activation of striato-nigral input or artificial synaptic inhibition produced a PSTH consisting of an initial depression of firing followed by oscillatory increases and decreases repeating at the SNr cell’s baseline firing rate. The phase resetting model produced PSTHs closely resembling the cell data, including the primary pause in firing and the oscillation. Key features of the PSTH, including the onset rate and duration of the initial inhibitory phase, and the subsequent increase in firing probability could be explained from the characteristic shape of the SNr cell’s PRC. The rate of damping of the late oscillation was explained by the influence of asynchronous phase perturbations producing firing rate jitter and wander. Our results demonstrate the utility of phase-resetting models as a general method for predicting firing in spontaneously active neurons and their value in interpretation of the striato-nigral PSTH. NEW & NOTEWORTHY The coupling of patterned presynaptic input to sequences of postsynaptic firing is a Gordian knot, complicated by the multidimensionality of neuronal state and the diversity of potential initial states. Even so, it is fundamental for even the simplest understanding of network dynamics. We show that a simple phase-resetting model constructed from experimental measurements can explain and predict the sequence of spike rate changes following synaptic inhibition of an oscillating basal ganglia output neuron.

Initial Severity and Antidepressant Benefits

This chapter provides a summary of a landmark study on major depressive disorder. What are the drug–placebo differences among antidepressants when both published and unpublished data are analyzed? Does antidepressant efficacy depend on the severity of initial depression scores? Starting with these questions, it describes the basics of the study, including funding, study location, who was studied, how many patients, study design, study intervention, follow-up, endpoints, results, and criticism and limitations. The main finding from this meta-analysis is that antidepressant-placebo differences are inconsequential for mildly-to-moderately depressed patients and minimal for severely depressed patients. The chapter briefly reviews other relevant studies and information, discusses implications, and concludes with a relevant clinical case.

Mechanisms of synaptic depression at the hair cell ribbon synapse that support auditory nerve function

Inner hair cells (IHCs) in the cochlea are the mammalian phono-receptors, transducing sound energy into graded changes in membrane potentials, the so called “receptor potentials.” Ribbon synapses between IHCs and auditory nerve neurons are responsible for converting receptor potentials into spike rates. The characteristics of auditory nerve responses to sound have been described extensively. For instance, persistent acoustic stimulation produces sensory adaptation, which is revealed as a reduction in neuronal spike rate with time constants in the range of milliseconds to seconds. Since the amplitude of IHC receptor potentials is invariant during this period, the classic hypothesis pointed to vesicle depletion at the IHC as responsible for auditory adaptation. In this study, we observed that fast synaptic depression occurred in responses to stimuli of varying intensities. Nevertheless, release continued after this initial depression, via synaptic vesicles with slower exocytotic kinetics. Heterogeneity in kinetic elements, therefore, favored synaptic responses with an early peak and a sustained phase. The application of cyclothiazide (CTZ) revealed that desensitization of postsynaptic receptors contributed to synaptic depression, which was more pronounced during stronger stimulation. Thus, desensitization had a twofold effect: It abbreviated signaling between IHC and the auditory nerve and also balanced differences in decay kinetics between responses to different stimulation strengths. We therefore propose that both pre- and postsynaptic mechanisms at the IHC ribbon synapse contribute to synaptic depression at the IHC ribbon synapse and spike rate adaptation in the auditory nerve.

Effectiveness of Group Behavioural Activation for Depression: A Pilot Study

Background: The evidence base for behavioural activation (BA) is mainly grounded in the individual delivery method, with much less known about the impact of group delivery. Aims: To conduct a pilot study of behavioural activation in groups (BAG) for depression delivered in a routine service setting, in order to explore acceptability, effectiveness and predictors of outcome. Methods: The manualized group treatment format was delivered in a Primary Care mental health setting, at step three of an Improving Access to Psychological Therapies (IAPT) service. BAG was facilitated by cognitive behavioural psychotherapists, and outcome measures (depression, anxiety and functional impairment) were taken at each session. Seventy-three participants were referred and treated within nine groups. Results: BAG was an acceptable treatment generating a low drop-out rate (7%). Significant pre–post differences were found across all measures. There was a moderate to large depression effect size (d+ = 0.74), and 20% met the criteria for a reliable recovery in depression. Greater severity of initial depression and attendance of at least four BAG sessions predicted better outcomes. Conclusions: BAG appears to be an effective depression treatment option that shows some clinical promise. Further larger and more controlled studies are nevertheless required.

Initial depression severity and response to antidepressants v. placebo: patient-level data analysis from 34 randomised controlled trials

SummarySeveral often-cited meta-analyses have reported that the efficacy of antidepressant medications depends on the severity of depression. They found that drug–placebo differences increased as a function of initial severity, which was attributed to decreased responsiveness to placebo among patients with severe depression rather than to increased responsiveness to medication. We retested this using patient-level data and also undertaking a meta-analysis of trial-level data from 34 randomised placebo controlled trials (n = 10 737) from the NEWMEDS registry. Although our trial-level data support prevous findings, patient-level data did not show any significant effect of initial depression severity on drug v. placebo difference.

Minimal clinically important difference on the Beck Depression Inventory - II according to the patient's perspective

BackgroundThe Beck Depression Inventory, 2nd edition (BDI-II) is widely used in research on depression. However, the minimal clinically important difference (MCID) is unknown. MCID can be estimated in several ways. Here we take a patient-centred approach, anchoring the change on the BDI-II to the patient's global report of improvement.MethodWe used data collected (n = 1039) from three randomized controlled trials for the management of depression. Improvement on a ‘global rating of change’ question was compared with changes in BDI-II scores using general linear modelling to explore baseline dependency, assessing whether MCID is best measured in absolute terms (i.e. difference) or as percent reduction in scores from baseline (i.e. ratio), and receiver operator characteristics (ROC) to estimate MCID according to the optimal threshold above which individuals report feeling ‘better’.ResultsImprovement in BDI-II scores associated with reporting feeling ‘better’ depended on initial depression severity, and statistical modelling indicated that MCID is best measured on a ratio scale as a percentage reduction of score. We estimated a MCID of a 17.5% reduction in scores from baseline from ROC analyses. The corresponding estimate for individuals with longer duration depression who had not responded to antidepressants was higher at 32%.ConclusionsMCID on the BDI-II is dependent on baseline severity, is best measured on a ratio scale, and the MCID for treatment-resistant depression is larger than that for more typical depression. This has important implications for clinical trials and practice.