I believe everyone has dark thoughts, I have them constantly. Although I try my best to do things to keep my mind off of topics that usually trigger a depressive state. I do the usual, listen to music, write, read, draw, sing—Anything to keep my mind off of anything that can lead me to feel bad. Sometimes, none of those help, because at times it is best to talk things over with a trusted person. I'm very bad at expressing myself and usually bottle everything inside. So sometimes that is not an option for me...
I don't mean to be cheesy but getting into the MLP fandom has been a blessing in disguise. At my age, everyone looks at me and wonders why I'm still watching cartoons. I'm an "adult" and should be doing "adult" things. It is poppycock I say, watching a cartoon doesn't define whether your behavior is adultlike or not. Sorry, got a little off topic there. But really, these ponies have been a life saver.
Tarot has been a wonderful empowerment tool for me as well, assisting me in my writing, art, as well as life. As long as one wants to take their mind off of whatever is bothering them, causing them pain, they will be able to do so. At least, that's my opinion. It's most certainly difficult, we all have our inner demons, it is not easy to ignore them. All we can do is try though.