Byline: M. Reddy, Arindam. Chakrabarty
Rest is a basic biological need. Sleep is a vital, highly organized process regulated by complex systems of neuronal networks and neurotransmitters. Sleep has an important role in the regulation of CNS and body physiologic functions, regulating metabolism, catabolism, temperature, learning, and memory consolidation. [sup] Sleep architecture is easily susceptible to external and internal disruption.
Insomnia is a symptom that arises from multiple environmental, medical, and psychological and mental disorders. [sup] Insomnia can be transient, short-term, or chronic in its presentation. In a typical psychiatric practice, 50-80% of adult patients experience significant problems with falling or staying asleep during any year. [sup] While 30-48% individuals report some problem in sleeping in a year, when diagnostic criteria were used for insomnia syndrome, 6% of the respondents indicated a disorder of insomnia that impaired daytime function. [sup] The insomnia syndrome becomes chronic when it is present for a month or longer and is defined by whether it is primary or associated with comorbid disorders. It is estimated that 10-15% of patients who have chronic insomnia are of primary origin. Insomnia that is comorbid with psychiatric disorders, medical disorders, circadian rhythm disorders, or substances or medications accounts for nearly 85-90% of chronic insomnia. [sup]
The Sleep Disorders Workgroup of the Diagnostic and Statistical Manual Committee of the American Psychiatric Association defines diagnostic criteria as problems of sleep onset, maintenance, early awakening, or nonrestorative sleep on more than half of the days for at least 1 month that are associated with significant daytime dysfunction that impair the performance of activities at home or work. [sup] The DSM-IV-TR [sup] segments chronic insomnia into primary insomnia or insomnia related to other conditions. A state-of-the-science conference held at the National Institute of Health in 2005 described the circular rather than the linear association among insomnia, psychiatric disorders, and medical illness, suggesting the term "comorbid insomnia" to describe the association. [sup] Primary insomnia subsumes several insomnia diagnoses in the International Classification of Sleep Disorders [sup] including psychophysiologic insomnia, sleep-state misperception, idiopathic insomnia, and some cases of inadequate sleep hygiene.
In 2004, a workgroup of the American Academy of Sleep Medicine published criteria to be used in research trials for the insomnia syndrome. [sup] Research trials generally require a reported sleep-latency of 30 or more minutes to be eligible for enrollment. If the problem of sleep maintenance is to be studied, at least 30 minutes of wakefulness after sleep onset may be required, with many recent trials using 60 or more minutes of wakefulness. Sleep efficiency (time asleep while in bed) must be less than 85%. Although 1 month of sleep disturbance is required in the DSM-IV-TR for chronic sleep disturbance, many patients experience transient and short-term insomnia. [sup] Transient insomnia presents and then passes after a few days, typically developing during a brief adjustment reaction, rotating shifts, or international travel. Short-term insomnia is characterized by 4-28 days of poor sleep. The common precipitants for short-term insomnia include illness, job change, bereavement, dissolution of a relationship, or other significant life stressor. [sup]
Although the duration of the insomnia complaint is relevant to psychiatrists, the selection of therapeutic intervention may be better based upon the time of night that patients complain of sleep disturbance, [sup] namely, along a continuum of sleeponset, sleep maintenance and early awakening.
In the last decade, the view of the relationship between sleep and psychiatric disorders has undergone a radical change. …