Circadian Rhythm Sleep Disorders

Patients with Alzheimer's disease may suffer the same age- and disease-related changes to sleep as their age-matched peers. However, as the dementia progresses, even more severe disturbances develop, with impairments in both nighttime sleep continuity and daytime alertness. This article focuses on long-term, holistic approaches to treatment, including environmental and behavioral interventions to augment sleep medications.

There is growing epidemiologic and clinical data that confirm progressive hypothalamic-pituitary-gonadal hypofunctioning in aging men. What role does the HPG axis play in the complex psychobiology of male sexual and affective disorders? The treatment rationale, clinical indications and risks in using exogenous testosterone for late-life depression are explored.

Seasonal affective disorder affects 1% to 3% of the North American population. Evidence exists for the efficacy of high-intensity bright, fluorescent light. Pharmacological management with SSRIs has shown equivalent efficacy to light therapy. How can these two therapies be combined? What other therapies are available?

Sildenafil (Viagra, Pfizer) may help patients recover from stroke by aiding regeneration of brain cells. After successfully proving that the drug stimulates cortical neurogenesis in experimental models of stroke, researchers from the Henry Ford Hospital in Detroit have now embarked on a clinical trial of sildenafil and plan to recruit 84 patients who have suffered a moderate stroke within 72 hours of entering the study.

Although light therapy is an old treatment, new therapeutic uses are being researched. What is the optimal time and strength of light treatment to best help patients with depressive disorders?

After reading this article, you will be familiar with:The function of the hypothalamic-pituitary-adrenalaxis and the significance of cortisolin the etiology of depression.

In modern practice, psychiatrists will invariably have patients who come from different ethnic or cultural backgrounds. Practitioners will need to consider socioeconomic status, diet, use of herbal medications and immigration status, as well as patients' own self-perception of ethnicity, in assessing patients and planning treatment.

Many patients, particularly those living in colder climates, can suffer from seasonal affective disorder (SAD). What causes SAD and what are the treatment options for these patients?

While progress in identifying the specific genetic variations that help determine an individual's vulnerability to addiction has been slow, a great deal has been uncovered about delineating the role that numerous genes and their protein products play in mediating the development of addiction.

The author examines how temperature and length of day can affect mood and behavior, both in a general population and a group of inpatients. In both groups, there were two peaks of violent behavior, one in May-June and one in October-November, which correspond with the equinoxes. Is it possible to track violent behavior in various geographical areas depending upon weather and length of day?

As chief of the division of sleep and chronobiology in the department of psychiatry at the University of Pennsylvania School of Medicine, David F. Dinges, Ph.D., focuses on ways sleep and the endogenous circadian pacemaker interact to control wakefulness and waking neurobehavioral functions such as physiological alertness, attention, cognitive performance, fatigue, mood, neuroendocrine profiles, immune responses and health. In an interview with Psychiatric Times, Dinges discussed neurobehavioral consequences of sleep loss, factors that impair sleeping, the pervasiveness of sleepiness and new ways to manage sleepiness.

Daniel F. Kripke, M.D. has studied the relationship between biological rhythms and depression since the early 1970s. He states that seasonal responses in many mammals are controlled by the photoperiod. Therefore, it seemed that depression might be analogous to winter responses and that light might be an effective treatment.

In recent years, melatonin has been touted in the media as a "hot sleeping pill, natural and cheap" and as the drug that "may help ease insomnia, combat jet lag...and extend life." Trials are finally being conducted. Across the United States, some 30 medical centers are studying melatonin as a potential treatment for sleep disturbances.

Today, average young adults report sleeping about seven to seven and one-half hours each night. Compare this to sleep patterns in 1910, before the electric lightbulb, the average person slept nine hours each night. This means that today's population sleeps one to two hours less than people did early in the century.

Since 1980, criteria for diagnosing bipolar disorder in adults have also been used to diagnose mania in children, with some modifications to adjust for age.

At this time, both patients and professionals seem to have an unprecedented interest in circadian rhythms. We now know that the body's clock is located in the suprachiasmatic nucleus (SCN) of the hypothalamus, and that the SCN regulates the pineal gland's secretion of the hormone melatonin.

Insomnia, the subjective sense of having inadequate quantity orquality of sleep, may result from a variety of causes. In itschronic form, such etiologies may include psychiatric disorderssuch as depression or anxiety, medical illnesses, medications,substance abuse, circadian dysrhythmias and pathophysiologiesintrinsic to sleep such as sleep apnea or periodic movement disorder.When these conditions have been ruled out, however, there remaintwo very interesting groups that at this time are best understoodin psychophysiological terms.