It's hard to know what would help without knowing the specific cause, but there are some comparatively-likely things to check: diet, micronutrients, exercise, sleep, and amount of social interaction. If any of these have changed recently, try changing them back. There is at least one blood test I'm aware of that should have be done (thyroid). You also might go back and ask your doctor for a different antidepressant without or with different side effects.
The only major change in these lately has been exercise - I went from none to running for an hour about three times a week - but that's post-onset.
My girlfriend suffers serious depression. She has sleep disorder, anorexia, chronic pain, problems to concentrate, low selfesteem, daily low mood, listlessness and is very indecisive. On the other side she considers herself very happy apart from the "depression periods" and we have a great time together. We already consulted a psychotherapist, but there is waiting time about one month. I buyed her fishoil capsules, because she eats no fish and there is mild evidence that it helps treating depression (I don't think this will affect her depression greatly, but fishoil seems like an overall good idea). We often go on walks to catch some sunlight and get her some exercise.
She says she never want's to take antidepressants because she fears to get dependent from them. I think she might change her mind if there are very good arguments in favour of them. She is quite rational in spite of not knowing the LW-stuff. Does anybody of you know if there is any information of the succes rate of medicamentous (and psycho therapeutic) treatment available?
I highly appreciate any advice.
Furthermore i want to call attention to the topic of depression. A huge share of the population suffers at least once in their lifetime under depression (~20% in Germany). Sadly it's often not taken serious and a big taboo to speak about. Many people see it as self-inflicted. My girlfriend's mother doesn't believe in depression as a disease (see diseased thinking). It's a paradigm of irrationality that hurts people.