Excerpt from an interesting article about lying and bipolar disease.
http://www.bipolar-lives.com/bipolar-and-lying.html
In my opinion, bipolar and lying go together with bipolar grandiosity, diminished need for sleep, racing thoughts and overall impulsivity and impaired judgment. The person with bipolar disorder may be experiencing a powerful sense of superiority and entitlement, and/or an unshakable conviction they are above the rules and/or an aching feeling of being misunderstood and under-appreciated that is, the perfect storm!
During an episode, the normal self is temporarily replaced by someone who is convinced they are special and superior. He or she is now so wrapped up in themselves that they can only perceive other people and events
through their own self-engrossment. Nothing has significance except for how it relates to their wonderful, perfect self right here and right now. What are some examples of our societys special or superior people? Think about
royalty, celebrities, presidents, third-world dictators. Often, we see such people acting as if they can play by a different set of rules. They are above the law. Bipolar liars may have such an inflated sense of self-importance
that they feel suffocated and constrained by everyday life. Great Ones do not have to stick to drab and suffocating facts, especially if the truth stands in opposition to seemingly brilliant insights and moments of revelation (rather than the base and tawdry need for excitement that others may perceive).
Remember, in grandiosity the perception is not just of being special. It is a conviction of being superior. This means having more value than others and more importance than others. It is a hierarchical perception. The grandiose bipolar liar is not just the center of their own delusional universe they are ABOVE others. This may mean also being above the usual norms of behavior. It is a special sense of immunity and entitlement.
This is why it is so typical for bipolar liars to not only express no remorse but to act as if they are actually the injured party. In their delusional state, they experience any attempt to limit their behavior (for example with the truth) as a malicious and unjustified act of control and domination. Any effort to reason with them will be perceived as manipulative, and ironically may even be perceived as selfish or cruel. They are a bright and shining star and any attempt to curb their manic behavior is a petty, jealous attack by mere mortals who resent true greatness."