Chronic depression is hugely common with autism spectrum disorders. I have a huge time with it, with my mood swinging like a pendulum between sort of okay to extremely down and depressed, at times when thoughts of suicide seem like the real easy option. What makes is worse (for me at least) is that the best coping strategy I was told was to throw myself as much as possible into my special interest, but the problem is that I don't want to do that when depressed, and that makes the depression even worse. Medication doesn't seem to help me much either. Seeking 'professional help' is difficult because counselors don't really understand Asperger depression and so look for a cause (are you unhappy in your job, your marriage or life generally). I'm not (my job is occasionally problematic but not enough to make me suicidal). There is often NO underlying cause and I'm pretty sure it's pure brain chemical or miswiring, because there isn't a single thing that can make me THAT unhappy. What stops me is the thought of the absolute misery I would cause to my family, and leaving my dogs behind. I suspect, deep down, I'm also afraid of doing it. I know exactly how, and how easy it would be, but I think I still fear it.

The only thing I've found to help has been talking to 'professionals' - and by that I mean autism professionals rather than the common therapist. Since diagnosis I've been lucky to have a good support structure with an autism specialist and specialist social worker who works within the autism field, both of whom have helped me after a recent hard meltdown which was followed by huge bout of depression. If that's possible for you to do, I recommend seeking out that help. In the UK the National Autistic Society is a good place to start unless you already have post-diagnostic support. If you are elsewhere then others here might be able to recommend a way forward.

Good luck - and know you're not alone. It's unfortunately common. :(