magog, I have mentioned before on the boards that I have trich. That was actually how I “discovered” that I have OCD and what caused me to first seek out a psychiatrist (trich is highly correlated to OCD).
Thankfully, I have extremely thick hair and you can’t tell that I “pull” (unless you are my hairdresser who has said something about all the “scars” on my scalp :eek: ), but I pull A LOT. I try to find the hairs that are thicker than the other ones or curlier and those are the ones I target. This is embarrassing, but recently I’ve even begun eating the roots off the end of the hair (if they pull out, too). In much more severe cases, people have been known to eat all of the hair and then they have to have the “hairball” surgically removed over time.
I don’t really know what you mean about a “bad habit”. Smoking is a bad habit, but it’s an addiction - one that temporarily relieves stress for some people. That’s how I look at the trich - I do it more when I’m nervous (you should have seen the floor next to my desk after MBA school tests!) or extremely tired. Believe it or not, the small amount of “pain” it causes me is extremely comforting.
I have done lots of behavioral therapy (putting all the hairs I pull during the day into a box and then counting them at the end of the day, wearing a rubber band around my wrist and “snapping” it every time I feel the urge to pull), but to no avail.
I am currently on 450mg. (yes, a high dose) of Effexor for the OCD/trich and take Xanax as needed for anxiety. The OCD has improved pretty dramatically, but the trich has not. I guess overall I’m not too worried about the trich now that I don’t go back five times to see if I’ve turned off the oven or have raging bulimia (also a compulsion) anymore. I see a psychologist every two weeks and a psychiatrist every 4 weeks, or so.
I’ve been under the care of a psychiatrist for almost five years now and have tried Prozac, Wellbutrin and now Effexor to combat it.
I hope I’ve answered some of your questions. I’m extremely open about it and will be happy to answer anything else for you. 
BTW, terms like pull, trich, and trichster (noun) are often used when talking about trichotillomania (literally, “hair madness”).