I think there's a spectrum when it comes to lying. If everyone who lies has a personality disorder, I'd better call my brother up and tell him to go get help, lol. My brother told lies when we were children, more frequently than I did likely, mostly in embellished stories and when he wanted a "Ferris Bueller" kind of day off from school, but he is certainly not bipolar, nor does he have a personality disorder...

I read somewhere that people with personality disorder lie without purpose. Just because they can pretty much or because they enjoy manipulating others, and people without, have a purpose for their lying.

In my brother's case, we egged him on with the tall tales because they were quite entertaining. He enjoyed telling them as much as I enjoyed hearing them, and wanting a day off from school is something I think most kids have wanted at some point. He was far from a pathological lier, though, and never lied to hurt anyone else.

I've told similar lies. Most are to protect myself in some way. I, too, pretended to be "sick" on occasion, which is half true, considering I was mentally ill during all those times. I also have lied by omission several times. I know it would greatly hurt my mother to know all the things I've done while in manic episodes, so I've chosen not to tell her everything. Some of the lying by omission was more that I was in denial to my condition. When doctors asked me about various symptoms, I downplayed them.