Enhancing plasticity to treat depression and other central nervous system diseases using event-driven pharmacology.

Summary

A new pharmacological model called event-driven pharmacology (EDP) is described, in which a plastogen—a drug that induces lasting neural plasticity—produces sustained effects after only transient binding, unlike traditional drugs that require continuous receptor occupancy. Plastogens such as ketamine and classical psychedelics can trigger metaplasticity, priming synapses to respond to later stimuli long after the drug has left the body. Dosing such drugs to maintain constant target occupancy may paradoxically reduce benefits and increase side effects. The EDP model calls for new drug development, dosing strategies, and biomarkers to harness the therapeutic potential of plastogens for depression and other synaptic disorders.

Study at a glance

Abstract

The occupancy-driven pharmacology model in psychopharmacology has guided drug discovery and development for decades, whereby the goal is stable receptor occupancy over an extended period with a direct relationship of drug exposure to pharmacodynamic and therapeutic response. Event-driven pharmacology (EDP) is a concept where the acute pharmacodynamic actions of a plastogen, a transient binding event, drive changes resulting in sustained pharmacodynamic effects that greatly outlast the time frame of drug exposure. Such plastogens may be neuroplastogens producing a measurable change in neuroplasticity without inducing subjective mental states or psychoplastogens exerting neuroplastic effects in addition to causing dissociation, hallucinations, or psychotomimetic symptoms. Within neuropsychiatry, plastogens have been shown to induce long-lasting neural plasticity and persistently activate synaptic machinery that primes synapses to respond to subsequent stimuli (metaplasticity), often following either a single dose or repeated administration of intermittent doses. Developing rapid-acting plastogens to adhere to a traditional target occupancy dose optimization model that achieves consistent drug target occupancy over an extended period of time may paradoxically exert few or no durable benefits while increasing side effect burden. We review evidence supporting the concept that plastogens, including the rapid-acting antidepressant ketamine and classical psychedelics, operate within the EDP model. With the emergence of EDP, new methods for drug development, clinical dosing, and biomarker adoption will need to be developed to account for distinctive pharmacological actions. Rapid-onset plastogens, rationally administered, have profound potential in the treatment of depression and many other neurological and psychiatric diseases characterized by synaptic dysfunction.

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