Cortico-striato-thalamo-cortical circuit — a neural feedback loop connecting the orbitofrontal cortex, caudate nucleus, thalamus, and anterior cingulate cortex. Chronically hyperactive and "locked" in OCD, generating intrusive thoughts and compulsive responses. Psilocybin's proposed mechanism in OCD is normalisation of fronto-striatal connectivity within this loop — distinct from its default mode network disruption mechanism in depression.
The CSTC (cortico-striato-thalamo-cortical) circuit is a neural feedback loop connecting the orbitofrontal cortex, caudate nucleus, thalamus, and anterior cingulate cortex. Chronically hyperactive and "locked" in OCD, it generates intrusive thoughts and compulsive responses. Psilocybin's proposed mechanism in OCD is normalisation of fronto-striatal connectivity within this loop — distinct from its default mode network disruption mechanism in depression.
See: OCD (/conditions/ocd).
The CSTC circuit explains why OCD may respond to psilocybin through a different pathway than depression — fronto-striatal normalisation rather than DMN disruption.