Randomized Controlled Trial of the Effects of High-Dose Ondansetron on Clinical Symptoms and Brain Connectivity in Obsessive-Compulsive and Tic Disorders.

Objective: Sensory phenomena (SP) are aversive sensations driving repetitive behaviors in obsessive-compulsive disorder (OCD) and Tourette's disorder that are not well addressed by standard treatments. SP are related to the functioning of an interoceptive-sensorimotor circuit that may be modulated by the 5-HT receptor antagonist ondansetron. The present study employed an experimental medicine approach to test the effects of 4 weeks of high-dose ondansetron compared to placebo on SP severity and brain connectivity in a cohort of individuals with OCD and/or Tourette's disorder.

Intrinsic and extrinsic control impact motivation and outcome sensitivity: the role of anhedonia, stress, and anxiety.

Background: Motivated behaviors vary widely across individuals and are controlled by a range of environmental and intrinsic factors. However, due to a lack of objective measures, the role of intrinsic extrinsic control of motivation in psychiatric disorders remains poorly understood.

Methods: We developed a novel multi-factorial behavioral task that separates the distinct contributions of intrinsic extrinsic control, and determines their influence on motivation and outcome sensitivity in a range of contextual environments.

Effects of vagus nerve stimulation on daily function and quality of life in markedly treatment-resistant major depression: Findings from a one-year, randomized, sham-controlled trial.

Background: Depression treatments aim to minimize symptom burden and optimize quality of life (QoL) and psychosocial function.

Objective: Compare the effects of adjunctive versus sham vagus nerve stimulation (VNS) on QoL and function in markedly treatment-resistant depression (TRD).

Methods: In this multicenter, double-blind, sham-controlled trial, 493 adults with TRD and ≥4 adequate but unsuccessful antidepressant treatment trials (current episode) were randomized to active (n = 249) or sham (n = 244) VNS (plus treatment as usual) over a 12-month observation period.

The genetics of severe depression.

Genome-wide association studies (GWASs) of major depressive disorder (MDD) have recently achieved extremely large sample sizes and yielded substantial numbers of genome-wide significant loci. Because of the approach to ascertainment and assessment in many of these studies, some of these loci appear to be associated with dysphoria rather than with MDD, potentially decreasing the clinical relevance of the findings. An alternative approach to MDD GWAS is to focus on the most severe forms of MDD, with the hope that this will enrich for loci of larger effect, rendering their identification plausible, and providing potentially more clinically actionable findings.