Demystifying Depression/Speculation on the Physiology of Depression
Speculation on the Physiology of Depression
Some interesting speculations about depression:
- Neuron death in the hippocampus has been implicated in depression 
- Neurogenesis (the birth of new neurons) may be necessary for recovery 
- Neurogenesis happens continuously in the healthy adult brain
- Most antidepressants require about 2-3 weeks to have an effect
- Stress may diminish neurogenesis
- People under stress may sleep less than usual
- In some cases those recovering from depression sleep more than normal all though the opposite is true in some cases
- Aging mimics several aspects of depression
- As people age, they sleep less, spend less time in deep sleep, and wake up more often 
- Neuron death and birth happens continuously in the adult brain
At least certain parts of the brain continuously renew themselves. Sleep seems to be fundamental for this renewal process---perhaps neurogenesis happens during sleep.
- Stress affects sleep, and by consequence, neurogenesis
There is plenty of speculation concerning the exact mechanism by which stress causes neuron death. Our own conjecture is based on the fact that when under stress, people sleep less than normal. Therefore, rather than directly killing neurons, stress might simply cause the brain to fall behind on its normal regenerative process.
- Increase in activity fundamental during recovery
Some studies show how stimulating environments help with neurogenesis . The reason might be similar to recovery from an injured limb: one has to gradually push the brain into continuing its recovery.