I've suffered from depression off/on since at least middle school. I first took anti-depressants in elementary school, though I'm not sure why and I don't remember feeling "depressed". However, I would have bouts all through college and most recently just a couple months ago it was really bad. I fought it off for about a year - stayed engaged in school, engaged in work, maintained my relationships where I could - but after about 5 months of that I started to fall apart, and around 10 months of that I started missing work and getting weaker.
Around the 10 month mark (this past March) I could barely get out of bed. It hurt to eat, hurt to not eat. Hurt to move, hurt to not move. I just decompensated and crashed. My parents had to drive 14 hours over the weekend to come down to my house and feed me and get me to see a doctor. I had no strength. It took a lot of energy to literally hold my head up. I was gripping my shirt like runners do when their arms are tired.
I had taken Zoloft in the past when things got rough, so I knew that was a medicine which agreed with me. I started Zoloft at 50mg for 2 weeks then at 100mg. I could tell a noticeable difference. I have more control over my thoughts. I used to say, "I'll probably kill myself before 30." Then I made it to 30, and I would say "I'll probably kill myself before 40." But medicated with anti-depressants and anti-anxiety meds, I don't think so strongly that way. When I start thinking something negative, instead of getting stuck I can stop myself and think about an alternative. Instead of brooding I can take a break. I'm not as drained, and I swear this leg pain that's been nagging me for over a year has significantly improved (along with other meds for it which I took before the Zoloft).
There is some research that says SSRI's help with body pain/chronic pain, though less so than other classes of antidepressants, but I swear it helps with my leg pain in my case. I recently drove 14+ hours and barely complained about my leg hurting.
I'm fairly certain that I have a genetic predisposition to depression. Not only because my parents took me to psychologists early in life, but because both my parents and at least 1 brother takes antidepressants, and I know other extended family members have struggled with chronic depression.
I struggled off/on with addiction over the past 4 years, and I'm almost certain it was a natural instinct to self-medicate. I wasn't raised around drugs or alcohol, but I just loved certain illegal substances. I speculate that the alcoholism in my extended family (uncle and grandfather) was also born out of a natural instinct to self-medicate. I don't know much about them, but I do know that I feel less inclined to use substances when I'm steady on Zoloft. (I take other meds too at bedtime, but I didn't notice a remarkable difference in my thoughts until the anti-depressant.)
A final note about depression - it doesn't present in any one way, and it presents differently in the same person based on their circumstances and environment. In college (10 years ago), I would get daily tension headaches for 6 months straight before seeing a doctor. I would get persistently angry and then angrier. My mood would fluctuate significantly from morning to noon to night, highly dependent on environmental stressors and responsibilities at different parts of the day. Those symptoms didn't happen with this most recent bout of depression a couple months ago, but notice the similarities in being unable to control thoughts, to manage internal conflict, and to brood.
Since I'm pretty sure I have some genetic predisposition, I think I'll be taking antidepressants throughout adulthood. Perhaps not always, but at least off/on. At this point in my life and with the benefit of hindsight, I'm at least open to the idea.