Serotonin HELP please??

Low serotonin levels are not the cause of depression - that is well-known now, but the drug companies and public information campaigns oversimplify and like to make it sound like the cause of depression is understood. It's not. And there may be multiple causes. No one knows, yet. Some people feel better when they take a pill that raises serotonin levels, but I just read that a new psychiatric drug LOWERS serotonin levels and that helps some people with depression.