| Serotonin (5-HT) | Implicated in mood regulation, sleep, and appetite |
| Norepinephrine (NE) | Involved in arousal, attention, and stress response |
| Dopamine (DA) | Related to motivation, reward, and pleasure |
| Anterior Cingulate Cortex (ACC) | Altered activity |
| Amygdala | Hyperactivity and increased emotional reactivity |
| Thalamus | Altered connectivity |
| Huntington's Disease | High depression prevalence |
| FTD | Behavioral variant FTD often presents with depression |
| Multiple System Atrophy | Depression common |
| Databases | OMIMOrphanetClinicalTrialsPubMed |