28 SLEEP PHASE DISORDER [Rev 10-21-2017]
This is one of the special conditions listed in Step B. It follows Section 38, as one dramatic outcome when daily life puts a person out-of-synch with their own circadian rhythms or the rhythms of other people or their social environment.
Here we consider people whose internal clock is different from the 24-hour phases that most of our lives are built around. These people’s circadian (about a day) rhythms may be about the same duration as most people, but they begin and end at different times from other people and the rest of their world.
28a Types
There are two basic types
- People with a delayed sleep phase, that begins and ends later than others.
- People with an advanced sleep phase, that begins and ends earlier than others.
In either case, a person’s daily cycle puts him/her in increasingly difficult time managing life smoothly with others and the rest of the world. Some people seem to like having time alone when others are asleep; but for most, it creates more problems than benefits. Often their sleep patterns lead them into conflicts with family and the requirements of work or school.
DELAYED SLEEP PHASE
We sometimes see this in adolescents, who stay up very late on the computer, or watching television, or hanging out with friends, then sleep late on subsequent days.
Commonly, people with this tendency are pulled back into standard sleep timing by a need to go to work or school. During weekends and vacations, the tendency can get more pronounced.
Although they have trouble going to sleep and waking at socially acceptable times, they may have no difficulty getting to sleep or staying asleep, if they are allowed to do it on their own schedules (Reite, Weissberg and Ruddy, p.102).
Some people stay up later and later, to the point that they are totally out of synch with the rest of the world, going to sleep at dawn and sleeping through the day.
For some people, this process of shifting sleep phase may be attributed (Glovinsky and Spielman, 157) to a person’s internal circadian pacemaker, which is set for a longer day than usual. (Does this happen more to males? If “men are from Mars,” and Mars has a period of rotation of 24 hours 37 minutes…) For others, it may be a consequence of the kinds of activities they engage in as bedtime approaches – eg.: watching old movies all night on television.
ADVANCED SLEEP PHASE
The opposite happens to some people, often as a part of ageing. The go to bed earlier and earlier over time. However, their actual sleep needs are not increasing in a corresponding way, so they also awaken earlier and earlier. They may complain of awakening too early without keeping track of the actual number of hours they sleep.
28b. Treatment
Patient motivation may be a more important consideration than with patients who have other types of sleep disorder. As Sack (p.184) points out, some people like their unusual life style and have difficulty understanding why others may object to it. If their life style is having a negative impact on others, the others may need to be involved in setting up the treatment.
Several approaches are possible for helping a person modify a person’s sleep-wake cycle. Many authors focus on light management to adjust the person’s circadian rhythm. At least, this approach should be considered, because if a person’s light habits remain intact, other approaches are less likely to be effective.
Light management is discussed in Section 27. In general, bright light tends to be alerting; and if the person is exposed to bright light in the morning, his/her sleep-wake cycle tends to move earlier. If the person is exposed to bright light in the evening, the cycle tends to move later. See Section 27 for more on this.
Reite, Weissberg and Ruddy (p.106) favor a combination of evening light reduction, timed morning light exposure, and melatonin (Section 22)
However, there are many other approaches to changing a person’s sleep cycle. For help falling asleep, the methods of Step D1 (Section 17 and following) can be used. When a person can fall asleep earlier, the cycle gets shifted in that direction, including waking earlier. For help with a cycle that is too early, the methods of Step D2 can be used to help shift the person’s cycle later.
If the person can take two weeks or more to change his/her sleep cycle, then Glovinsky and Spielman (pp: 158-161) and Reite, Weissberg and Ruddy (p.106) suggest “chronotherapy”, in which bedtime is systematically delayed to a later and later time. Eventually, the successive delays go around the clock, placing the person into a schedule that matches everyone else. If the person also has slightly less than usual amount of sleep each night, there will be a drive to remain on the new schedule.
28c. Special Treatment
Sleep specialists make a point of the relationship between body temperature and timing in a person’s sleep-wake cycle. Body temperature can be used as a gauge for the timing of bright light treatment (Hauri and Linde, pp 152-153). This may be difficult to do in outpatient treatment, and referral to a sleep lab may be indicated.