Thank you for this provocative question. Surely, it is true that most people with DSPD and ASPS, although they realize their sleep is displaced relative to the norm, do not identify the situation as a “disorder” or attribute it to their circadian rhythms. Many of them accommodate it by making a circle of friends with similar sleep patterns (active phone calling after midnight, etc.) and finding jobs that do not require a 9-5 work schedule (bartending, acting, free-lance writing, etc.) Importantly, however, many also experience depression, and cannot maintain self-supporting employment or family life. Some, with partners who sleep normal hours, develop serious conflicts at home (even with the threat of divorce). When such problems develop, you will recognize that you have a serious problem, but still you are unlikely to attribute it to a circadian rhythm disturbance.
The Center for Environmental Therapeutics has a major goal of teaching people with ASPS and DSPD the nature of the problem and guiding them toward effective treatment and adjustment using the most potent method available–light therapy. Light therapy needs to be complemented with restricted lighting at other times of day in order to normalize the sleep pattern. In DSPD, for example, it is important to receive ample light exposure after sleep, but to minimize light exposure before sleep. The opposite holds for ASPS. People have achieved dramatic improvement using these simple techniques.