I find that a pretty incomplete and insufficient definition. It implies that anti depressants are some magic pills and that if you don't respond to two of them you are treatment resistant. We all know they are not magic pills and many people don't respond to them but may respond to therapy.

Am I treatment resistant?
I have been on many anti depressants over the last 20 years most of which have been totally ineffective. That would make me treatment resistant. However a couple have worked. Effexor with a low dose of Celexa worked pretty good for a long time. Effexor has been the best one for me but long ago pooped out. So we tried Pristiq and it didn't do anything. The latest one is Fetzima and it has been more effective than anything ever by far. It seems to be pooping already though. I have had to raise the dose once already and feel like I need to again and it has only been six months. So am I treatment resistant or not? I have no doubt that my recurrent cyclical depression will return fetzima or no fetzima like it always does.

This is why I think in the big picture I am treatment resistant-
Most meds don't work and the ones that do poop out. (thats a small part)
I have gone to much therapy and group therapy over the years. Always been 100% honest in therapy and in group.
I learned CBT in therapy and practice it everyday.
Started therapy again with someone who incorporates all the forms, CBT, DBT, and so on.
I practice mindfulness everyday.
Have very consistently meditated over the last twenty years.
Self help books and work books.
Spiritual books and practices.
Long time member of AA and practice its twelve steps and principles. Very similar to therapy with the added spiritual dimension. It is very focused on personal growth, changing thinking and behaviour, and spiritual growth. Have done my fair share of searching and fearless moral inventories and shared it all with someone.
Alanon, ACOA
A good support network.
A good fulfilling career.
Tons of exercise at work.

I am in no way perfect in these things but I have worked very hard at it. They have helped me immensely in daily living and in personal relationships and so on. I am not depressed all the time and it is when I am not depressed that they help. I am totally all for all those practices and they have helped me in general a ton.........

BUT I still get regular recurrent cyclical depression like I always have. it has gotten worse in recent years despite all these things that you would think would help alleviate it. When I am in the middle of a severe depression none of those things work even if I am able to practice them. I can be in the middle of working, getting lots of exercise, and everything is great and the depression will hit me like a ton of bricks out of the blue. It usually has to run its course and it always does. The length of time varies and it always returns. When it hits it is very severe. Suicidal, can't get out of bed, don't shower for weeks, severe.

What am I to do?
Whether that is treatment resistant I do not know. To me it is. It leads me to believe that in my case it is very genetically and biologically ingrained in me. it follows seasonal cycles. Not SAD but three or four times a year that I can set the calender by. There is also a family history that would back this up.