Uncontrollable worry is a core feature of generalized anxiety disorder and other mental health conditions. Mindfulness-based strategies can help reduce worry, but it is unclear which specific techniques work best and how they affect the brain. In a study of 40 participants with clinically significant worry, functional magnetic resonance imaging was used while they engaged in real-time worry and then tried to disengage using two mindfulness strategies (focused attention, acceptance) and one comparison strategy (suppression). All disengagement strategies reduced activity in the default mode network and increased activity in frontoparietal and salience networks, indicating shared mechanisms.
Ketamine rapidly improves symptoms of treatment-resistant depression (TRD), but because TRD varies widely among patients, markers are needed to personalize treatment. This study measured brain functional connectivity during positive mood processing in 152 adults with TRD before they received either ketamine or a saline placebo. Two connectivity-based subgroups emerged: Subgroup A (110 patients) and Subgroup B (42 patients). Ketamine improved depression uniformly across both subgroups. However, among patients given saline, those in Subgroup B were more likely to show a placebo response 24 hours later than those in Subgroup A. Thus, brain connectivity patterns predicted placebo response but not ketamine response.