Vol 7 No.4 - Sleep Disorders, Neuropsychiatry, and Psychotropics
Past issues Contributors How to publish Contributions and comments Home
 
I n   t h i s   i s s u e . . . In our competitive society, is sleep a waste of time? Do lazy people sleep more than hyperachievers? Is brain activ- ity greatly reduced when we sleep? Do we just slowly and peacefully go from wakefulness into sleep when we are tired, and then simply wake up the next morning fresh and rested? Do we translate into dreams what impressed us the day before? Although common sense would give affirmative answers to all of the above, the truth, as is often the case in the neurosciences, is much more complex. No, sleep is neither a waste of time, nor only for the lazy. On the contrary, the brain works very hard during sleep, and we struggle to make up for lost sleep with the same fervor with which we struggle for food or sex. No, we do not go slowly and peacefully from wakefulness into sleep; the transition is abrupt, and nightmares are more common than peaceful dreams. In fact, the transition is so abrupt that falling asleep is the reason for numerous accidents. And no, real- ity is not translated into dreams, but rather incompre- hensible and distorted fragments of reality appear in dreams in apparently chaotic sequences. As if normal sleep was not sufficiently complex, there exist about 100 sleep disorders grouped into hypersomnia, insomnia, parasomnia, and disturbances of circadian rhythm. Sleep-related complaints are second only to pain- related complaints as a reason for seeking medical atten- tion. In this issue of, Dialogues in Clinical Neuneuroscience we attempt to address the bidirectional relationship between normal and abnormal sleep/wakefulness, on the one hand, and psychiatric illnesses, on the other. The authors of the articles in this issue also examine how psychotrop- ic drugs mediate this relationship. In the State of the art article, Vivien C. Abad and Chris- tian Guilleminault (page 291) review the major mental ill- nesses and the sleep disorders that may be associated with each. They also examine the effects on sleep of var- ious psychotropic drugs. They conclude that sleep prob- lems and psychiatric disorders constitute closely linked conditions that exacerbate each other, impair quality of life, and cause disability. In the first Basic research  article, Olivier Le Bon (page 305) examines the relationship between sleep and depres- sion, with a focus on the role of sleep research in devel- opment of antidepressant drugs, particularly with respect to insomnia, which is currently considered to be a major health concern. Much remains unanswered in this field, because antidepressants do not act in a uniform way on sleep: some reduce slow-wave sleep, while others increase it; some prolong rapid-eye movement (REM) latency, while others shorten it. Analysis  of  sleep  microstructure,  ie,  the  electroen- cephalographic (EEG) features and phasic (20- to 30-s) phenomena occurring during well-defined sleep stages, can be used to evaluate both normal and pathological sleep processes. In his Basic research article, Alain Muzet (page 315) provides a detailed description of the use of changes in sleep microstructure to obtain valuable infor- mation for both diagnosis and prognosis of psychiatric disorders. In the Pharmacological aspects article, Luc Staner (page 323) describes the effects of psychotropic drugs and sub- stances on specific brain neurotransmitter systems and cir- cuits involved in the physiology of sleep. Because the cor- rective effects of psychotropic drugs on dysfunctional neurotransmission systems can be observed polysomno- graphically, Staner considers sleep as a kind of “window” on the neurobiology of psychiatric disorders. The first article in the Clinical research section, by José Haba-Rubio (page 335), focuses on the effect of sleep disorders on mood, drawing attention to the fact that, occasionally, “treatment refractory depression” is in fact an undiagnosed and untreated parasomnia or hyper- somnia. Complementing the first article, the second Clinical research article, by Yves Dauvilliers and Alain Buguet (page 347), deals with the more common hyper- somnia syndromes, which are complaints of excessive daytime sleep or sleepiness. Although lack of nighttime sleep is the first etiology to be suspected, hypersomnia syndromes may have a number of different causes, each with their corresponding treatment. The last Clinical research  article is by Yaron Dagan and Katy Borodkin (page 357), who focus on circadian rhythm disturbances and their implications on psychiatric morbidity. They believe that these disorders are relatively easy to diagnose and treat, yet many cases remain unrecognized or misdi- agnosed as psychiatric disorders or psychophysiological insomnia. Michael Davidson, MD