Stress and inflammation in depressive episode subtypes and pain
| Features | Melancholic episode | Atypical episode | Pain |
|---|---|---|---|
| Mood | Flat, anhedonia | Reactive | - |
| Worsening of mood | Morning | Evening | - |
| Insomnia | Early awakening | Hypersomnia | Insomnia |
| Eating behavior | Hyporexia | Craving for carbohydrates | - |
| Activity | Slowdown | Leaden paralysis | Fatigue |
| Innate immunity | ↑ | ↑ | ↑ |
| Adaptive immunity | ↑ | ↑ | ↑ |
| TNF-α | ↑ | ↑ | ↑ |
| IL-1 | ↑ | ↑ | ↑ |
| IL-6 | ↑ | - | ↑ |
| CRP | ↑ | - | ↑ |
| BBB | Decreased | - | - |
| DexST | Suppressed | Normal | Normal |
| SNS | ↑ | - | ↑ |
| CRF | ↑ | ↓ | - |
| ACTH | ↑ | ↓ | Normal stress stimulus response |
| Cortisol | ↑ at basal level | Reduced production | Blunted stress stimulus response |
| KYN | ↑ | - | ↑ |
| 5HT | ↓ | ↓ | ↓ |
| GABA | ↓ | - | ↓ |
| BDNF | ↓ | ↓ | ↓ |
↑: hyperactivity or increased level; ↓: hypoactivity or decreased level; -: no date. TNF-α: tumor necrosis factor-α; IL-1: interleukin-1; CRP: C-reactive protein; BBB: blood-brain barrier; DexST: dexamethasone suppression test; SNS: sympathetic nervous system; CRF: corticotropin-releasing factor; ACTH: adrenocorticotropic hormone; KYN: kynurenine; 5HT: serotonin; GABA: gamma-aminobutyric acid; BDNF: brain-derived neurotrophic factor