5. The Neuroscience of Differential Diagnosis: RSD and Its Neighbors

A clinically responsible account of RSD must address its relationship to adjacent conditions — not to diminish the validity of the construct, but to preserve distinctions that matter for treatment.

vs. BPD

BPD is organized around chronic fear of abandonment within a broader identity disturbance and pervasive relational dysregulation.12 RSD is more episodic and does not require the full BPD clinical picture, though both share the dACC–insula pain network.

vs. SAD

Social Anxiety is prospective — hypervigilant avoidance of evaluative situations. RSD is reactive — acute, overwhelming flooding in response to a rejection that has already occurred.7

vs. MDD

RSD-related depressive states are more episodic, more clearly linked to specific interpersonal triggers, and typically resolve faster once the relational situation is processed.8