Table 2.
The enzymes of the tryptophan-kynurenine pathways and related disease.
| Major Depressive Disorder | Bipolar Disorder | Generalized Anxiety Disorder | Substance Use Disorder | Post-Traumatic Stress Disorder | Schizophrenia | Autism Spectrum Disorder | ||
|---|---|---|---|---|---|---|---|---|
| Symptoms | Positive | + | ++ | ++ | ++ | ++ | ++ | + |
| Negative | ++ | ++ | ++ | + | ++ | ++ | + | |
| Cognitive | + | + | ++ | ++ | ++ | - | + | |
| Anxiety | ++ | ++ | ++ | ++ | ++ | ++ | ++ | |
| Inflammatory factors | Proinflammatory | ↑ | ↑ | ↑ | ↑ | ↑ | ↑ | ↑ |
| Anti-inflammatory | ↑ | ↑ | ↓ | ↓ | ↓,? | ↑ | ↑ | |
| Kynurenines | Toxic | ↑ | ? | ↑ | ? | ? | ↑ | ↑ |
| Protective | ↓ | ? (serum), ↑ (CSF) | ? | ? | ? | ↑,? | ↓ | |
+: noticeable; ++: prominent; -: not typical;↑: increase; ↓: decrease; ?: questionable or unknown.