I can't say that my bipolar has ever interrupted my cognitive abilities. I haven't had these issues. Only time I think it did affect me was when I was at work and the tediousness and stress of the job finally got to me.

I don't know what his issue really is, but the better sleep and eating habits will definitely help the bipolar. As for the lying aspect that's strictly him and it really has nothing to do with the bipolar.

Does he have a therapist? Sometimes the pills aren't the only answer. Talk therapy works wonders. You two should look into it if your budget allows.

Good luck.