My partner, mother and sister take ssri's. This is my mental model for them and the depression it treats. 1) I see depression as the relevant neurological area

My partner, mother and sister take ssri's. This is my mental model for them and the depression it treats. 1) I see depression as the relevant neurological area of the brain learning to get too good at paying attention to negativity. (Overfitting to associating things with bad feelings, outcomes etc) 2) serotonin is a key chemical in the process of learning which I model as changing the way we associate emotions with situations, things etc. 3) by taking ssri's you provide the brain with an excess of serotonin which increases the capacity to learn new emotional associations provided you are exposed to those situations and positive feelings / outcomes. In this way, I believe (based only on my own reading and more as a thought aid than anything else) that treating the checmical aspect of depression is only viable if you treat the environmental aspect simultaneously. So just taking ssri's won't work. You need a good, safe, supportive environment to learn to be positive in again.