Delayed sleep phase disorder (DSPD) is a circadian rhythm sleep disorder that is characterized by a sleep-wake cycle that is later than what is considered to be normal. The aim of management is to allow affected individuals to get the quantity and quality of sleep required by their body, such that they are not inhibited by symptoms of the condition.
Assessing Need for Treatment
Firstly, it is important to establish that not all individuals with DSPD require treatment. In fact, most people with the disorder will not experience any negative symptoms at all if they are allowed to sleep according to the natural rhythm of the body.
However, for most people strict schedules and work or study commitments in the morning restrict their sleep time. They are unable to fall asleep earlier but are required to wake up earlier, resulting in restriction of sleep and possible symptoms of sleep deprivation. These may include daytime sleepiness and decreased performance in studies or at work.
In general, if a patient reports unfavorable symptoms that they would like to improve, appropriate management techniques are indicated. First-line recommendations typically involve simple lifestyle changes to alter sleep habits, followed by more technical methods to alter the circadian rhythm and pharmacotherapy, which is the last line approach.
Improving Sleep Habits
The initial step in the management of DSPD is to improve the sleep habits with non-invasive techniques and align the sleep-wake cycle more closely with what is considered to be normal.
Good sleep habits include going to bed and waking up at approximately the same time each night. Certain substances, such as nicotine, caffeine and alcohol, can also keep individuals awake and delay the sleep cycle if consumed shortly before bedtime. Additionally, the sleep environment is important and excessive temperatures, light or sound that may disrupt sleep should be eliminated, if possible.
The blue light from electrical devices, such as the television, mobile phone or computer, is also associated with stimulation of the brain and may keep individuals awake if used at nighttime. Patients suffering from DSPD should be advised to avoid using these devices in the hours preceding bed.
If possible, the bedtime of the individual can gradually be shifted earlier to normalize the sleep cycle. This simply involves going to bed slightly earlier each successive night so that the body can slowly adjust to the new time and begins to feel tired earlier.
Light and Dark Therapy
Advancing the sleep-wake cycle can be assisted by light or dark therapy. This works on the principle that the circadian rhythm relies on light cues to determine the appropriate time to sleep and adjusts accordingly.
Individuals should avoid exposure to bright sunlight or blue light from electronic screens in the late evening and before bed. Conversely, in the morning specific exposure to bright light sends cues to the brain to awaken the body and, eventually, the body clock adjusts accordingly.
Chronotherapy is a technique used to reset the clock by delaying the sleep-wake cycle significantly, such that becomes aligned with the normal sleep time. This is based on the theory that it is easier to delay than to advance the sleep cycle, although is more drastic and requires more time for the individual to adjust to the changes.
When an appropriate sleep schedule has been reached, it is important for the individual to maintain the new habit, as the delayed phase can remit and cause them to fall back into the original pattern.
Finally, there are some pharmacological options that may help to aid sleep in patients with severe symptoms.
Melatonin is naturally present in higher concentrations in the body at approximately bedtime when feelings of tiredness peak. For this reason, it can be used to aid sleep when taken shortly before bedtime. Short-term side effects of melatonin may include disturbance while sleeping, sleepiness during the day and depression, and the long-term side effects have not been examined.
Modafinil is a stimulant that can be used to improve performance during the day for individuals affected by DSPD-related sleep deprivation. This should only be used in the morning, however, as it may delay the sleep phase further if taken in the afternoon or later.