The neuropsychopharmacology of treatment discontinuation

Neuropsychopharmacology has spent decades building a detailed science of how a treatment takes hold: receptor occupancy, intracellular signaling, circuit adaptation, and symptom change. What the field has not built, with equivalent rigor, is a science of what happens when the treatment stops. Stopping antidepressants, antipsychotics, benzodiazepines, and other psychoactive drugs is still largely managed through consensus-based tapering and brief monitoring plans. This is pragmatic. It is also a scientific gap masquerading as a clinical solution. Treatment discontinuation is not simply a pharmacological absence. It is an active neuroadaptive state shaped by pharmacodynamic rebound, allostatic counterregulation, and gene-regulatory carryover that can persist well beyond drug clearance (Fig. 1 ) [ 1 ]. The field has a science of treatment effects. Now it needs a science of treatment discontinuation. Fig. 1: Treatment discontinuation as an active neuroadaptive state. Full size image During sustained pharmacotherapy (left), compensatory adaptations accumulate progressively beneath the apparent stability of treatment response. These include target adaptation, allostatic loading, gene-regulatory remodeling, and expectation conditioning. These adaptations are clinically silent during treatment but go unopposed upon drug removal. At discontinuation, the abrupt loss of pharmacological input unmasks all adaptive layers simultaneously, generating an active neuroadaptive state characterized by pharmacodynamic rebound, allostatic counterregulation, gene-regulatory carryover, and nocebo/expectation activation. The trajectory through this discontinuation window—either toward recovery or toward relapse and destabilization—is shaped by the magnitude and interaction of these mechanisms, and by individual differences in vulnerability that current clinical practice does not systematically assess.