[Beardedsockeater (OP)]

Do antidepressants really make your dreams more vivid or is it because you're more likely to remember them? And if so, why? Is it the increased Serotonin in the brain? How is it doing this? Does this happen for everyone?  []

[chris]

I think there could be two aspects to the answer to this question:

Firstly, it could be that the antidepressants are making you feel better and hence you sleep better and for long enough to have memorable dreams. Over the course of a night the length of REM-phase sleep (when we dream) increases and with it the complexity of the dreams we experience.

Since depression frequently disturbs a person's sleep (a frequent symptom is early-morning waking, or failing to fall asleep in the first place) then it will also impact on REM sleep and the duration of REM sleep and hence dreaming. But treating someone will translate into better quality sleep and hence a return of normal dreaming. But because the depressed person has been used to poor sleep and little dreaming, suddenly it appears that they are dreaming a lot more.

Secondly, antidepressants also target a family of brain transmitter chemicals which include serotonin, dopamine and noradrenaline. Noradrenaline is produced from a brain region called the locus coeruleus, so-named because it is a blue colour owing to the presence of neuromelanin, a by-product of noradrenaline synthesis. Activity in the locus coeruleus is strongly linked to REM-phase sleep and dreaming, and since some of the newer antidepressants like roboxetine and venlafaxine (the SNRIs) target this transmitter system it's possible they could also impact on dreaming.

Chris