How do you counter a liar friend?

People with destructive personality traits (such as a pattern of lying) need the help of a mental health professional and even mental health specialists may not be able to *help* someone who exibits this behaviour, UNLESS the person in question recognises that they have a problem and UNLESS they are seeking to change their behaviour. Otherwise, lead by your good example, do not allow yourself to be taken advantage of, perhaps try to convey to your friend how their conduct affects others and how it in turn is also ultimately damaging to him/her and encourage your friend to seek counselling. Having said that, beware of anyone who lies and otherwise craps on you and then asks for your "help" as this is a manipulative ploy designed to get them more mileage out of you and, more likely than not, they revert back to their destructive habits. Again, the "help" this person needs ought to be sought from a PROFESSIONAL and it is really up to the person with the problem to take steps to address THEIR OWN behaviour via whichever avenue they think best -- but this is NOT your problem, nor is it something YOU can do much about. More likely than not, by trying to "help" you'll get suckered again. OCD (obsessive-compulsive disorder) is a serious condition that defies logic and will not be helped with discussion. You can tell your friend that his/her condition isn't real, he/she shouldn't do whatever it is and that it's really harmful for him/her to do whatever it is that is dictated by the OCD, but it won't do any good. The only thing that will truly help is medication. It shouldn't be something that makes him/her feel ashamed, so try to talk about it as openly and "matter-of-fact" as you can. Don't be judgmental. Don't tell him/her that it's all in his/her head and he/she should just "get over it". All of that kind of talk is incredibly counterproductive and causes the sufferer to become even MORE stressed. Some of the medications available are really quite incredible and once the individual can recognize the chemical imbalance component of his/her OCD he/she will be able to feel less of an outcast. Unfortunately, many suffers of OCD recognize the irrational behavior as being counter-productive, but still are drawn to it. Get help for your friend because this is something that you can't solve yourself. Friends can get educated about the disorder; there are many things a person can do to not contribute to the disorder. Ask a mental health professional, and there are also some Excellent books on the subject in libraries and book stores.