In early attempts to define the syndrome, sleep disturbances were briefly considered a criterion for AD/HD, but were dropped from the symptoms list because evidence of them was thought to be too nonspecific. As research has expanded to include adults with AD/HD, the causes and effects of sleeping disturbances have become clearer. Many researchers expect them to return as a diagnostic criterion when the criteria for adult AD/HD appear in the DSM V in 2010. For now, sleep problems tend either to be overlooked or to be viewed as coexisting problems with an unclear relationship to AD/HD itself. Sleep disturbances have been incorrectly attributed to the stimulant-class medications that are often the first to be used to treat AD/HD.
THE 4 BIG SLEEP ISSUES
No scientific literature on insomnia lists AD/HD as a prominent cause of sleep disturbances. Most articles focus on sleep disturbance due to stimulant-class medications, rather than looking at AD/HD as the cause. Yet adults with AD/HD know that the connection between their condition and sleep problems is real. Sufferers often call it “perverse sleep”—when they want to be asleep, they are awake; when they want to be awake, they are asleep. The four most common sleep disturbances associated with AD/HD are:
1. Initiation Insomnia
About three-fourths of all adults with AD/HD report inability to “shut off my mind so I can fall asleep at night.” Many describe themselves as “night owls” who get a burst of energy when the sun goes down. Others report that they feel tired throughout the day, but as soon as the head hits the pillow, the mind clicks on. Their thoughts jump or bounce from one worry to another. Unfortunately, many of these adults describe their thoughts as “racing,” prompting a misdiagnosis of bipolar mood disorder, when this is nothing more than the mental restlessness of AD/HD.
Prior to puberty, 10 to 15 percent of children with AD/HD have trouble getting to sleep. This is twice the rate found in children and adolescents who do not have AD/HD. This number dramatically increases with age: 50 percent of children with AD/HD have difficulty falling asleep almost every night by age 12½; by age 30, more than 70 percent of adults with AD/HD report that they spend more than one hour trying to fall asleep at night.
2. Restless Sleep
When individuals with AD/HD finally fall asleep, their sleep is restless. They toss and turn. They awaken at any noise in the house. They are so fitful that bed partners often choose to sleep in another bed. They often awake to find the bed torn apart and covers kicked onto the floor. Sleep is not refreshing and they awaken as tired as when they went to bed.
3. Difficulty Waking
More than 80 percent of adults with AD/HD in my practice report multiple awakenings until about 4 a.m. Then they fall into “the sleep of the dead,” from which they have extreme difficulty rousing themselves. They sleep through two or three alarms, as well as the attempts of family members to get them out of bed. AD/HD sleepers are commonly irritable, even combative, when roused before they are ready. Many of them say they are not fully alert until noon.
4. Intrusive Sleep
Paul Wender, M.D., a 30-year veteran AD/HD researcher, relates AD/HD to interest-based performance. As long as persons with AD/HD were interested in or challenged by what they were doing, they did not demonstrate symptoms of the disorder. (This phenomenon is called “hyperfocus” by some, and is often considered to be an AD/HD pattern.) If, on the other hand, an individual with AD/HD loses interest in an activity, his nervous system disengages, in search of something more interesting. Sometimes this disengagement is so abrupt as to induce sudden extreme drowsiness, even to the point of falling asleep. Marian Sigurdson, Ph.D., an expert on electroencephalography (EEG) findings in AD/HD, reports that brain wave tracings at this time show a sudden intrusion of theta waves into the alpha and beta rhythms of alertness. We all have seen “theta wave intrusion,” in the student in the back of the classroom who suddenly crashes to the floor, having “fallen asleep.” This was probably someone with AD/HD who was losing consciousness due to boredom rather than falling asleep. This syndrome is life-threatening if it occurs while driving, and it is often induced by long-distance driving on straight, monotonous roads. Often this condition is misdiagnosed as “EEG negative narcolepsy.” The extent of incidence of intrusive “sleep” is not known, because it occurs only under certain conditions that are hard to reproduce in a laboratory.
The simplest explanation is that sleep disturbances are direct manifestations of AD/HD itself. True hyperactivity is extremely rare in women of any age. Most women experience the mental and physical restlessness of AD/HD only when they are trying to shut down the arousal state of day-to-day functioning in order to fall asleep. At least 75 percent of adults of both genders report that their minds restlessly move from one concern to another for several hours until they finally fall asleep. Even then, they toss and turn, awaken frequently, and sometimes barely sleep at all.
The fact that 80 percent of adults with AD/HD eventually fall into “the sleep of the dead” has led researchers to look for explanations. No single theory explains the severe impairment of the ability to rouse oneself into wakefulness. Some AD/HD patients report that they sleep well when they go camping or are out of doors for extended periods of time. Baltimore-based psychiatrist Myron Brenner, M.D., noted the high incidence of AD/HD individuals among the research subjects in his study of Delayed Sleep Phase Syndrome (DSPS). People with DSPS report that they can experience a normal sleep phase—For example, get into bed, fall asleep quickly, sleep undisturbed for eight hours, and awake refreshed—but that their brains and bodies want that cycle from 4 a.m. until noon. This is a pattern reported by more than half of adults with AD/HD. Brenner hypothesizes that DSPS and the sleep patterns of AD/HD have the same underlying disturbance of circadian rhythms. Specifically, he believes that the signal which sets the internal circadian clock (the gradual changes in light caused by the sun’s setting and rising) is weak in people with AD/HD. As a result, their circadian clock is never truly set, and sleep drifts into to the 4 a.m.-to-noon pattern or disappears entirely, until the sufferer is exhausted.
One hypothesis is that the lack of an accurate circadian clock may also account for the difficulty that many with AD/HD have in judging the passage of time. Their internal clocks are not “set.” Consequently, they experience only two times: “now” and “not now.” Many of my adult patients do not wear watches. They experience time as an abstract concept, important to other people, but one which they don’t understand. It will take many more studies to establish the links between circadian rhythms and AD/HD.