Pharmacological treatment of psychiatric disorders remains challenging in clinical, pharmacological, and scientific practice. Even if
many different substances are established for treating different psychiatric conditions, subgroups of patients show only small or no
response to the treatment. The neuroinflammatory hypothesis of the genesis of psychiatric disorders might explain underlying
mechanisms in these non-responders. For that reason, recent research focus on neuroinflammatory processes and oxidative stress
as possible causes of psychiatric disorders. G-protein coupled receptors (GPCRs) form the biggest superfamily of membrane-bound
receptors and are already well known as pharmacological targets in various diseases. The G-protein coupled receptor 55 (GPR55), a
receptor considered part of the endocannabinoid system, reveals promising modulation of neuroinflammatory and oxidative
processes. Different agonists and antagonists reduce pro-inflammatory cytokine release, enhance the synthesis of anti-
inflammatory mediators, and protect cells from oxidative damage. For this reason, GPR55 ligands might be promising compounds
in treating subgroups of patients suffering from psychiatric disorders related to neuroinflammation or oxidative stress. New
approaches in drug design might lead to new compounds targeting different pathomechanisms of those disorders in just one
molecule
