Antidepressants Don’t Work the Way Many People Think
The [current prevailing theory](https://www.biologicalpsychiatryjournal.com/article/S0006-3223(19)30037-X/fulltext), Dr. Hellerstein said, is that chronic stress can cause the loss of connections — called synapses — between cells in the hippocampus and other parts of the brain, potentially leading to depression. Antidepressants are now thought to work at least in part by helping the brain form new connections between cells. Researchers aren’t exactly sure how increasing serotonin with an S.S.R.I. causes these synapses to regrow. One possibility is that the medications also [increase levels of other brain chemicals](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4763983/), called growth factors, that help those connections form and spread.