Guanfacine as a Treatment for Posttraumatic Stress Disorder in an Adolescent Female

Alpha-2 Agonists in Children and Adolescents With Post-traumatic Stress Disorder: A Systematic Review

Exposure to traumatic stress is common among children. Post-traumatic stress disorder (PTSD) is a debilitating chronic mental disorder that can develop following exposure to a traumatic event. Psychopharmacological research in pediatric PTSD is limited. There is some evidence supporting the use of alpha-2 (α2) agonists for symptoms associated with PTSD. This systematic review identified published studies evaluating the effectiveness of α2 agonists in treating PTSD symptoms in children and adolescents. We conducted an extensive literature search on PubMed, MEDLINE, EMBASE, Cochrane Collaboration, and PsycINFO databases for published articles that evaluated the use of α2 agonists (clonidine and guanfacine) for treating symptoms of PTSD in children and adolescents. The study protocol was registered in Prospero (ID: CRD42021273692) and followed the PRISMA guidelines. A total of 10 published articles about clonidine or guanfacine use in PTSD in children and adolescents were identified. Studies found clonidine effective in reducing PTSD symptoms; however, the effects were variable. Clonidine and guanfacine showed effectiveness in treating nightmares, hyperarousal, aggression, and sleep disturbances and reducing re-experiencing, avoidant, and hyperarousal symptom clusters. No randomized, double-blind, placebo-controlled trials were found during the literature search. α2 agonists' effectiveness in treating symptoms associated with PTSD in children and adolescents is preliminary. Future placebo-controlled trials are needed to assess the efficacy and safety of α2 agonists.

An ensemble recruited by α2a-adrenergic receptors is engaged in a stressor-specific manner in mice

α2a-adrenergic receptor (α2a-AR) agonists are candidate substance use disorder therapeutics due to their ability to recruit noradrenergic autoreceptors to dampen stress system engagement. However, we recently found that postsynaptic α2a-ARs are required for stress-induced reinstatement of cocaine-conditioned behavior. Understanding the ensembles recruited by these postsynaptic receptors (heteroceptors) is necessary to understand noradrenergic circuit control. We utilized a variety of approaches in FosTRAP (Targeted Recombination in Active Populations) mice to define an ensemble of cells activated by the α2a-AR partial agonist guanfacine ("Guansembles") in the bed nucleus of the stria terminalis (BST/BNST), a region key to stress-induced reinstatement of drug seeking. We define BNST "Guansembles" and show they differ from restraint stress-activated cells. Guanfacine produced inhibition of cAMP-dependent signaling in Guansembles, while chronic restraint stress increased cAMP-dependent signaling. Guanfacine both excited and inhibited aspects of Guansemble neuronal activity. Further, while some stressors produced overall reductions in Guansemble activity, active coping events during restraint stress and exposure to unexpected shocks were both associated with Guansemble recruitment. Using viral tracing, we define a BNST Guansemble afferent network that includes regions involved in the interplay of stress and homeostatic functions. Finally, we show that activation of Guansembles produces alterations in behavior on the elevated plus maze consistent with task-specific anxiety-like behavior. Overall, we define a population of BNST neurons recruited by α2a-AR signaling that opposes the behavioral action of canonical autoreceptor α2a-AR populations and which are differentially recruited by distinct stressors. Moreover, we demonstrate stressor-specific physiological responses in a specific neuronal population.