In the neurobiology of major depressive disorder, the 'kindling hypothesis' proposes that:
- A Repeated episodes of depression progressively lower the threshold for future episodes, eventually becoming autonomous ✓
- B Serotonin deficiency is the sole cause of depression
- C BDNF excess causes hippocampal overdevelopment in depression
- D Episodes become less frequent over time due to neural compensation
Explanation
The kindling hypothesis, proposed by Robert Post, states that initial depressive episodes are triggered by environmental stressors, but with repeated episodes, the neurobiological changes (including reduced BDNF, hippocampal volume loss, HPA axis dysregulation) progressively lower the threshold for subsequent episodes. Eventually, episodes occur spontaneously without identifiable triggers, analogous to electrophysiological kindling. This has therapeutic implications: preventing early episodes with maintenance treatment is more effective than treating recurrent episodes, and explains why the number of prior episodes is the strongest predictor of recurrence.
Reference: Kaplan & Sadock's Synopsis of Psychiatry, 11th ed.
High-yield for: NEET PGINI-CETNExTFMGEUSMLEPLABMRCP
Written and medically reviewed by the StethoPrep medical team.