Although "severely elevated mood" sounds somewhat desirable and enjoyable, the experience of mania is ultimately often quite unpleasant and sometimes disturbing, if not frightening, for the person involved and for those close to them, and it may lead to impulsive behaviour that may later be regretted. It can also often be complicated by the sufferer's lack of judgment and insight regarding periods of exacerbation of characteristic states. Manic patients are frequently grandiose, obsessive, impulsive, irritable, belligerent, and frequently deny anything is wrong with them. Because mania frequently encourages high energy and decreased perception of need or ability to sleep, within a few days of a manic cycle, sleep-deprived psychosis may appear, further complicating the ability to think clearly. Racing thoughts and misperceptions lead to frustration and decreased ability to communicate with others.