'Sleep Drunkenness' Disorder Highly Prevalent

Megan Brooks

August 27, 2014

Confusional arousals affect roughly 1 in 7 adults and are often associated with sleep or mental disorders independent of medication use, a new study finds.

"These episodes of waking up confused have received considerably less attention than sleepwalking even though the consequences can be just as serious," study author Maurice M. Ohayon, MD, DSc, PhD, director of the Stanford Sleep Epidemiology Research Centre (SSERC) in Palo Alto, California, said in a statement.

"The patient might not always be aware of these episodes or at least, of what she/he did during an episode," Dr. Ohayon told Medscape Medical News. "Many people think these episodes are mundane and without consequences. It is true most of the time. However, it takes only 1 episode to have disastrous consequences because judgment and spatio-temporal orientation are impaired during an episode," he explained.

The new study is published in the August 26 issue of Neurology.

Dr. Maurice M. Ohayon

Ties to Mental Illness, Sleep Disorders

Confusional arousals (CAs), also known as sleep drunkenness or severe sleep inertia, involve mental confusion or inappropriate behavior during or following arousals from sleep, typically from slow-wave sleep in the first part of the night, but also upon awakening in the morning. An episode can be triggered by a forced awakening and may even cause violent behavior during sleep or amnesia of the episode.

In this report, the authors note that CA is not considered a disorder in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders), "probably because it has received little attention from the scientific community. However, including CA as a sleep disorder in the major classifications would increase awareness among physicians and patients and contribute to its identification, research, and treatment," they write.

In a cross-sectional study of 19,136 people age 18 years and older from the general US population, 2421 (15.2%) reported CAs in the prior year. More than half (53.8%) reported having at least 1 episode per week, while 24.7% had 2 to 5 episodes per month. CAs occurred as often in men as women.

The episodes were typically of short duration, the authors say, lasting 15 minutes or less in 69.9% of cases; 36.4% of those with CAs reported sleep-related hallucinations and 14.8% also reported episodes of nocturnal wanderings. Seven percent of CAs were accompanied by nocturnal wanderings and violent behavior during sleep. CAs may be followed by complete or partial amnesia of the episode.

Overall, 84% of CAs were associated with a sleep disorder (70.8%) (most often dyssomnia and parasomnia) or a mental health disorder (37.4%), including depression, bipolar disorder, alcoholism, panic or post-traumatic stress disorder, and anxiety.

Most adults reporting CAs were not receiving medication, but among those who were, antidepressants were most common. Hypnotics and anxiolytics were not related to CA episodes; however, people with sleep apnea also were more likely to report CAs.

"Confusional arousals impaired cognitive abilities of the individuals to have adapted responses to the environment. In the most serious situations, individuals may harm themselves or someone else," Dr. Ohayon told Medscape Medical News.

"Their frequent association with sleep and mental disorders is underlining the need for the people to talk about it with their physician, especially if they happen several times per month. The physician will explore with the patient what are the factors most likely to trigger confusional arousal episodes and offer some solutions to minimize or stop their occurrence," Dr. Ohayon said.

An "Important" Study

M. Safwan Badr, MD, immediate past president of the American Academy of Sleep Medicine, told Medscape Medical News that this is "an important cross-sectional study that enhances our understanding of confusional arousals, a parasomnia that is common but frequently unrecognized by physicians. 

"The most important finding of this study is that confusional arousals rarely occur in isolation — about 1% of the time in this study sample," added Dr. Badr, chief of the Division of Pulmonary, Critical Care and Sleep Medicine at Wayne State University School of Medicine in Detroit, Michigan.

"We have known for some time that obstructive sleep apnea is a common precipitant of confusional arousals, which this study supports. However, the new epidemiologic data also provide surprisingly strong evidence that numerous other sleep disorders may be triggering factors for confusional arousals — including circadian rhythm sleep-wake disorders, hypersomnias, insomnia, and restless legs syndrome," Dr. Badr said.

He added, "Although we have believed that confusional arousals rarely are associated with psychological pathology, this study provides intriguing new evidence suggesting that risk factors for confusional arousals may include mental disorders such as bipolar disorder, panic disorder, major depressive disorder, generalized anxiety disorder and posttraumatic stress disorder. This finding is noteworthy and deserving of further study."

The finding that both antidepressant use and alcohol dependence are associated with confusional arousals also is of "clinical relevance," although "less surprising," Dr. Badr said.

"Based on the common occurrence of a multitude of complex risk factors for confusional arousals, patients should be referred to a board-certified sleep medicine physician for a comprehensive sleep evaluation when they present with complaints — often from a bed partner — of frequent or disturbing episodes of confusional arousals, or when these episodes are accompanied by abnormal aggression or sexual behaviors," Dr. Badr advised.

The study was supported by the Arrillaga Foundation. The authors have disclosed no relevant financial relationships.

Neurology. 2014;83:834-841. Abstract