Sleeplessness and Circadian Rhythm Disorder

Circadian Rhythm Disorder Overview

A person's circadian rhythm is an internal biological clock that regulates a variety of biological processes according to an approximate 24-hour period. Most of a person's body systems demonstrate circadian variations. The body systems with the most prominent circadian variations are the sleep-wake cycle, the temperature regulation system, and the endocrine system.

The malfunctioning of a person's circadian system, or biological clock, causes circadian rhythm disorders. The circadian rhythm disorder related to the sleep-wake cycle can be categorized into the following 2 main groups:

• Transient disorders
  
  • Jet lag
    
    
  • Altered sleep schedule due to work hours or social responsibilities
    
    
  • Illness
    
• Chronic disorders
  
  
• Delayed sleep-phase syndrome (DSPS)
  
  
  • DSPS is characterized by a persistent (that is, lasting longer than 6 months) inability to fall asleep and awaken at socially acceptable times. Individuals with DSPS fall asleep late (for example, in the early morning hours) and wake up late (for example, in the late morning hours or in the early afternoon hours).
    
    
  • Once asleep, however, persons with DSPS are able to maintain their sleep and have normal total sleep times. In contrast, persons without DSPS who are unable to sleep because of difficulties initiating and maintaining sleep have a lower than normal total sleep time than persons with DSPS.
    
• Advanced sleep-phase syndrome (ASPS)
  
  
  • ASPS is characterized by a persistent early evening sleep onset time (between 6:00 pm and 9:00 pm) and an early morning wake-up time (between 3:00 am and 5:00 am).
    
    
  • ASPS occurs less frequently than DSPS and is most commonly seen in elderly individuals and in individuals who are depressed.
    
• Irregular sleep-wake cycle
  
  
• An irregular sleep-wake schedule features multiple sleep episodes without evidence of recognizable ultradian (a series of shorter biological rhythms occurring within a 24-hour period) or circadian features of sleep and wakefulness.
  
  
• As in persons with ASPS and DSPS, total sleep time is normal in persons with an irregular sleep-wake schedule.
  
  
• Daily sleep logs demonstrate irregularity not only of sleep but also of daytime activities, including eating.

Circadian Rhythm Disorder Causes

Most of the time, a person's biological clock, or circadian rhythm, is in synchronization with the 24-hour day-night environment. In some individuals, however, the biological circadian rhythm of sleep and wakefulness is out of phase with the conventional or desired sleep-wake schedule. Some reasons for this breakdown may include the following:

• Sensitivity to zeitgebers ("time givers," such as light and other environmental cues): This sensitivity may be altered or disrupted, which can be demonstrated under certain conditions. Altered or disrupted sensitivity to zeitgebers is probably the most common cause of the circadian rhythm disorder of the sleep-wake cycle.

• Disrupted pacemaker function: Adysfunction may be present in the internal coupling mechanisms of biological pacemakers, for example, the coupling of the sleep-wake cycle with the temperature cycle.

• Environment: Light, higher noise levels, and elevated room temperature are not conducive to good sleep and are important variables to consider in both shift workers and night workers.

• Travel: The severity of jet lag is related to the direction of travel and is more frequently seen in individuals traveling in an eastward direction. The number of time zones crossed also has an effect on the severity of jet lag, with most individuals experiencing jet lag if they cross 3 or more time zones. The rate of adjustment is 1.5 hours per day after a westward flight and 1 hour per day after an eastward flight.

• Neurological disease: Alzheimer disease is one of the more common examples of neurological disease associated with a circadian rhythm disturbance; however, irregular sleep-wake cycles can also be seen in other neurodegenerative diseases. Sundowning, which is a common phenomenon in persons with Alzheimer disease, is characterized by sleep disruptions with awakenings and confusion.

• Shift work: Rapid shift changes and shift changes in the counterclockwise direction are most likely to cause symptoms of a circadian rhythm disorder.

• Lifestyle and social pressure to stay up late can exacerbate a circadian rhythm disorder.

Circadian Rhythm Disorder Symptoms

Symptoms commonly found in persons with a circadian rhythm disorder related to the sleep-wake cycle can include the following:

• Difficulty initiating sleep
  
  
• Difficulty maintaining sleep
  
  
• Nonrestorative sleep
  
  
• Daytime sleepiness
  
  
• Poor concentration
  
  
• Impaired performance, including a decrease in cognitive skills
  
  
• Poor psychomotor coordination
  
  
• Headaches
  
  
• Gastrointestinal distress

Circadian Rhythm Disorder Treatment

Self-Care at Home

As always, maintaining good sleep hygiene is important. Good sleep hygiene consists of measures to reinforce the body's natural tendency to sleep, including the following:

• Adhering to consistent sleep and wake times
  
  
• Avoiding napping
  
  
• Using the bed only for sleeping and intimacy
  
  
• Avoiding stress, fatigue, and sleep deprivation
  
  
• Avoiding vigorous exercise at least 4 hours prior to bedtime (Regular exercise is recommended.)
  
  
• Avoiding cigarettes, alcohol, and caffeine at least 4-6 hours prior to bedtime
  
  
• Avoiding large meals and excessive fluids before bedtime
  
  
• Controlling the environment, including light, noise, and room temperature (A controlled sleeping environment is especially important for shift workers and night workers.)

Medical Treatment

Common circadian rhythm disorder treatments can include the following behavioral and environmental therapies:

• Chronotherapy: This behavioral treatment consists of gradually shifting the sleep time in accordance with the person's desired schedule. Thus, in DSPS, a progressivedelay of 3 hours per day is prescribed, followed by strict maintenance of a regular bedtime hour once the desired schedule is achieved. In ASPS, chronotherapy focuses on advancing a regular bedtime hour by 2-3 hours per night for 1 week until a desired schedule is achieved.
  
  
• Bright light therapy: Persons with a circadian rhythm disorder respond well to light therapy, especially bright light therapy (greater than 600 lux). To modify the phase of the circadian rhythm, bright room light over time may also be sufficient; however, a higher intensity of light (greater than 6000 lux over 30-60 minutes) is often necessary to accomplish significant changes in sleep cycles. The timing of light therapy is also important because it affects the degree and the direction of the rhythm shift. For example, for persons with ASPS, light therapy applied in the early evening and nighttime hours delays the cycle, whereas, for persons with DSPS, light therapy applied in the early morning hours stimulates morning alertness and an earlier bedtime.
  
  
• Enhancing environmental cues: This part of the treatment of a circadian rhythm disorder is important. Persons are encouraged to keep a dark and quiet room during sleep and a well-lit room upon awakening. Avoiding bright light exposure in the evening and enforcing regular hours for eating and other activities also help.
  
  
• Lifestyle: Persons may respond to shifts in their active phases by exhibiting signs of sleep deprivation. For example, teenagers may have difficulty keeping late hours and getting up for an early morning class. Shift workers may have difficulty adjusting to new sleep cycles if their shifts are changed too rapidly before their bodies have had a chance to adjust.

Medications

Therapy for a circadian rhythm disorder is largely behavioral. Light therapy has been shown to be an effective modifier of circadian rhythms. The short-term use of hypnotics (medications that promote sleep) is a useful option in treating a circadian rhythm disorder and has improved the therapeutic response, especially in persons with Alzheimer disease.

Melatonin

Melatonin has been reported to be useful in the treatment of jet lag and sleep-onset insomnia in elderly persons with melatonin deficiency. Melatonin is used for enhancing the natural sleep process and for resetting the body's internal time clock when traveling through different time zones. Melatonin is believed to be effective when crossing 5 or more time zones but is less effective when traveling in a westward direction. Melatonin has also been used in the treatment of circadian rhythm sleep disorder in persons who are blind with no light perception.

Melatonin is available as an over-the-counter(OTC) preparation. Melatonin is still considered a diet supplement, and dosing guidelines have not been established. Because of the effect of melatonin on immune function, persons with immune disorders and those taking systemiccorticosteroids or immunosuppressive drugs should be cautioned against taking melatonin. Melatonin may interact with other medications. Persons should consult their doctor before using melatonin.

Melatonin stimulants

Ramelteon (Rozerem) is a prescription drug that stimulates melatonin receptors. Melatonin is a hormone produced by the pineal gland during the dark hours of the day-night cycle (circadian rhythm). Melatonin levels in the body are low during daylight hours. The pineal gland (located in the brain) responds to darkness by increasing melatonin levels in the body. This process is thought to be integral to maintaining circadian rhythm. Ramelteon promotes the onset of sleep and helps normalize circadian rhythm disorders. Ramelteon is approved by the Food and Drug Administration (FDA) for insomnia characterized by difficulty falling asleep.

Hypnotics

Short-term use of hypnotics may be beneficial in selected patients. Patients interested in the use of hypnotics for a circadian rhythm disorder should discuss them with their doctor.

Benzodiazepines

Short-acting benzodiazepines are often chosen in the early treatment of a circadian rhythm disorder and are used in conjunction with behavioral therapy. Triazolam(Halcion) is a benzodiazepine frequently chosen for short-term use in addition to behavioral therapy. This short-acting agent is effective in helping persons fall asleep.

Triazolam is not effective in persons with sleep maintenance issues. For persons with sleep maintenance insomnia, a benzodiazepine with an intermediate half-life (for example, estazolam [ProSom]) or a long half-life (for example, quazepam[Doral]) may be considered.

Nonbenzodiazepine hypnotics

Nonbenzodiazepine hypnotics are gaining popularity because they do not have a significant effect on sleep architecture and are not associated with the reboundphenomenon seen with benzodiazepines. Zolpidem (Ambien) is a good short-term option for persons with DSPS who require pharmacologic support.

Treatment of sleep disorders associated with shift work

Modafinil (Provigil) is a stimulant indicated to treat workers with sleep disorders caused by their shift work. Modafinil has wake-promoting actions and is taken 1 hour before the start of the work shift.

Sleep Disorders in Women

Sleep Disorders in Women Overview

Women are twice as likely as men to have difficulties falling asleep or staying asleep. Younger women have sounder sleep with fewer disturbances. Some women, however, are prone to sleep problems throughout their reproductive years. Only recently has the medical community focused on women's sleep disorders.

A number of factors may affect women’s sleep. Changes in hormonal levels,stress, illness, lifestyle, and sleep environment may impact sleep. Pregnancy- and menstrual-related hormonal fluctuations may affect sleep patterns, mood, and reaction to stress. Many women have premenstrual sleep disturbances. Difficulty falling asleep, nighttime waking, difficulty waking up, and daytime sleepiness all are linked to premenstrual changes. Insomnia (sleeplessness) is one of the most common symptoms of premenstrual syndrome (PMS).

Psychosocial stress may threaten sleep more than hormonal changes. Many young women reduce sleep to cope with work and their roles as mothers and wives. They ignore fatigue and other effects of inadequate sleep. About 30% of employed women report sleep problems. Sleep problems are more common in women older than 40 years. Getting enough sleep improves job performance, concentration, social interaction, and general sense of well-being.

Pregnancy may also disturb sleep. During the first trimester, women need more sleep and feel sleepier during the day. During the second trimester, sleep improves. During the third trimester, women sleep less and are more awake. The most common reasons for sleep disturbances are frequent urination, heartburn, general discomfort, fetal movements, low back pain, leg cramps, and nightmares. Swelling in nasal passages may cause snoring and sleep apnea during pregnancy.

As women age, physical and hormonal changes make sleep lighter and less sound. Sleep disturbances become more common during menopause. Women wake up more often at night and are more tired during the day. Hot flashes andnight sweats linked to lower levels of estrogen may contribute to these problems. During the menopausal years, snoring becomes more frequent. After menopause, women get less deep sleep and are more likely to awaken at night than during menopause.

Pain, grief, worry, certain medical conditions, medications, and breathing disorders may disturb sleep in menopausal and postmenopausal women.

The most common sleep problem in women is insomnia. This includes trouble falling asleep, staying asleep, or early awakening, and inability to resume sleep. Other common sleep disorders are sleep-disordered breathing, restless legssyndrome, periodic limb movement disorder, and narcolepsy.

• Sleep-disordered breathing occurs with loud snoring, interrupted breathing during sleep, disrupted sleep, and daytime sleepiness. Sleep apnea increases in women older than 50 years.


• Restless legs syndrome (RLS) and periodic limb movement disorder (PLMD) can disturb sleep profoundly. The causes of these conditions are unknown. RLS occurs before sleep starts and causes calf discomfort and restlessness in the legs that is relieved by movement. PLMD causes periodic leg movements that may awaken the person from sleep. RLS may cause insomnia. PLMD may cause excessive sleepiness. Both conditions are more common in older people.


• Narcolepsy causes excessive daytime sleepiness. The major features of narcolepsy are sleep attacks and cataplexy. Sleep attacks are an irresistible urge to sleep. Cataplexy is a sudden loss of muscle tone typically preceded by emotional states. Other narcolepsy symptoms are sleep paralysis andhypnagogic hallucinations. Patients with narcolepsy often have disrupted sleep.

• Sleep Disorders in Women Causes

  • The changing hormonal levels during themenstrual cycle can disturb sleep and cause daytime sleepiness. Hormonal effects can be direct, by changing sleep patterns, or indirect, by affecting mood and emotional state. As many as 80% of women report premenstrual symptoms.
  
  
  • Decreasing menopausal estrogen levels may cause hot flashes that disturb sleep. About two thirds of menopausal women have sleep problems. Lower menopausal estrogen levels are linked with increased snoring risk and sleep-disordered breathing.
  
  
  • In today's society, many women cope with the roles of wife, mother, caregiver for parents, and worker. With less time for themselves, they often reduce sleep. The sleep deprivation and stress are linked with long-term insomnia.
  
  
  • Work and lifestyle can also contribute to primary sleep disorders. Women who work in rotating and night shifts are likely to experience sleep problems. Inactivity and lack of exercise can lead to trouble falling asleep. Women with erratic schedules or altered weekend sleep patterns are more likely to have trouble resetting their body clock to normal.
  
  
  • Caffeine, nicotine, or other stimulating drugs near bedtime may prevent a woman from falling asleep. Alcohol may cause sleep fragmentation and nightmares.
  
  
  • Depression and anxiety are more prevalent in women than in men and can contribute to sleep disorders. In some women, these are related to themenstrual cycle. Anxiety may impair falling asleep, and depression may cause early morning awakening.
  
  
  • Sleep-disordered breathing is common in postmenopausal women. Multiple breathing cessations during sleep occur with sleep apnea. The resulting breathing difficulty disturbs sleep and may cause daytime fatigue. Sleep apnea is linked to high blood pressure and cardiovascular disease.
  
  
  • Snoring often indicates partial airway obstruction. Snoring is linked with high blood pressure and increased risk for sleep apnea. Snoring increases during pregnancy, particularly during the last trimester. It is linked to pregnancy-related high blood pressure, pre-eclampsia, and low infant birth weight. Pregnant women do not have a higher risk of sleep-disordered breathing.
  
  
  • Sleep disorders are more common in older women.
  
  
  • Being overweight or obese increases a woman's risk of having a sleep disorder.
  
  

  Sleep Disorders in Women Symptoms

  There are 3 common sleep disorder symptoms. Overlap is common.

  • Difficulty falling asleep: This problem is more common in younger women. It is often linked to anxiety disorders and a stressful lifestyle.
  
  
  • Difficulties maintaining sleep: Multiple awakenings during sleep are more common in older women. This symptom may indicate periodic limb movement disorder (PLMD). Arthritis, pain, medications, and the last trimester of pregnancy may cause multiple awakenings during sleep.
  
  
  • Excessive daytime sleepiness: In older postmenopausal women, PLMD and sleep-disordered breathing may cause excessive daytime sleepiness. Sleep deprivation and narcolepsy are more likely to cause severe sleepiness in younger women.

  
  

  Sleep study

  • Polysomnography: Overnight sleep studies or polysomnograms may be done in a sleep disorders center, at home, or in a hospital. The machine records EEG (sleep patterns) breathing patterns, ECG, eye movements, and changes in muscle tone.
    
    
  • Multiple sleep latency test (MSLT): MSLT measures the level of daytime sleepiness. It is performed during the day following a supervised overnight polysomnogram.
    
    
  • Sleep log: A sleep log is a diary of your sleep-wake cycles. You will be asked to keep a 2-week diary of sleep and daytime sleepiness. This diary can be helpful in diagnosing circadian rhythm disorders as well as irregular sleep patterns

  
  

  Self-Care at Home

  Guidelines for better sleep hygiene

  Sleep hygiene refers to habits and lifestyle that promote healthy sleep. Your health care provider will often recommend improved sleep hygiene.

  • Try to wake up at the same time every day, regardless of the time you went to bed.

  • Try to stay away from long daytime naps, but a brief regular daily nap may be helpful.
  
  
  • Exercise daily but not in the hours before bedtime.
  
  
  • Use the bed only for sleeping or sex.
  
  
  • Do not read or watch television in bed.
  
  
  • Do not use bedtime as worry time.
  
  
  • Eat a balanced diet with regular mealtimes.
  
  
  • Avoid heavy or spicy meals at bedtime.
  
  
  • Avoid alcohol, caffeine, and nicotine before bedtime.
  
  
  • Spend time right before bed relaxing and engaging is soothing activities.
  
  
  • Develop a routine for getting ready for bed.
  
  
  • Control the nighttime environment with comfortable temperature, noise, and light levels.
  
  
  • Wear comfortable, loose-fitting clothes to bed.
  
  
  • If unable to sleep within 30 minutes, get out of bed and perform a soothing activity, such as listening to soft music or reading. Avoid bright light exposure during these times.
  
  
  • Get adequate exposure to bright light during the day.

  Weight loss may help overweight, habitual, loud snorers. Alcohol and sedatives before bed may aggravate snoring. Also, avoid sleeping on your back. Taping a tennis ball to the back of your bedclothes may prevent you from sleeping on your back.

  
  

  Medical Treatment

  Why doesn't your health care provider prescribe a sleeping pill for you? One reason is that sleeping pills may cause dependency and abuse. Also, sleeping pills may cause side effects and complications, such as confusion,dizziness, imbalance, falls, and a daytime "hangover." These medications are only a short-term solution.
  
  Your health care provider may treat medical or psychological sleep disorders or refer you to a specialist. Your health care provider may also change or discontinue medications to improve sleep.
  
  The treatment for sleep-disordered breathing iscontinuous positive airway pressure (CPAP. A mask is worn over the nose or mouth while you sleep, and gentle steady air pressure from the mask keeps your airway open. CPAP often provides immediate relief. Patients feel more rested at night and are more alert during the day.

  Medications

  Health care providers use short-term and long-term drug treatment to treat sleep disorders.
  
  Sleep medications are a short-term drug treatment for insomnia. Other names for sleeping medications are hypnotics or sedatives. The goal is to reduce insomnia without sacrificing daytime alertness. Short-term treatment lasts 2-4 weeks. The health care provider treats the underlying cause of the sleep disorder during this period.
  
  The most widely used sleep medications are the benzodiazepine and nonbenzodiazepine drugs. These medications are safe because they are difficult to overdose. Tolerance develops quickly, and over time, a higher dose is required to get the same effect as the initial dose. The risk of becoming dependent on these medications is high. These medications may cause withdrawal symptoms. These are the reasons for using sleep medications on a short-term basis. Examples are the benzodiazepines lorazepam (Ativan), triazolam(Halcion), and temazepam (Restoril) and the nonbenzodiazepines zolpidem (Ambien) and zaleplon (Sonata).
  
  Ramelteon (Rozerem) is a prescription drugthat stimulates melatonin receptors. Melatonin is a hormone produced by the pineal gland during the dark hours of the day-night cycle (circadian rhythm). Melatonin levels in the body are low during daylight hours. The pineal gland (located in the brain) responds to darkness by increasing melatonin levels in the body. This process is thought to be integral to maintaining circadian rhythm. Ramelteon promotes the onset of sleep and helps normalize circadian rhythm disorders. Ramelteon is approved by the Food and Drug Administration (FDA) for insomnia characterized by difficulty falling asleep.
  
  
  Long-term treatment consists of treating medical and psychological conditions that underlie sleep disorders. In some cases, the sleep disorder is treated directly.
  
  Hormone replacement therapy (HRT) improves sleep in menopausal women. HRT reduces hot flashes that disturb sleep. HRT may also improve sleep-related breathing disorders. HRT may be estrogen alone, or estrogen with progesterone. HRT is not for every woman, but it can markedly improve menopause symptoms. Long-term use of HRT involves risks. Make sure you understand the risks and benefits before you start HRT.
  
  Antidepressant drugs are sometimes used for women with chronic (long-term) insomnia. These drugs usually work, even in people who have no other depression. They also help some premenstrual sleep problems, postpartum depression, anxiety-related sleep disorders, and clinical depression. They alter brain chemicals called neurotransmitters, such as serotonin and norepinephrine. These drugs do not cause dependency. Examples are sertraline (Zoloft), fluoxetine(Sarafem or Prozac), and mirtazapine (Remeron).
  
  Stimulants are sometimes used to treat narcolepsy. These drugs promote wakefulness. An example is modafinil (Provigil).
  
  Dopamine agonists are drugs that promote release of the neurotransmitterdopamine in the brain. These drugs may improve restless legs syndrome. An example is pramipexole (Mirapex).

Seasonal Depression (SAD)

Seasonal Depression Overview

Seasonal affective disorder (SAD) is a type of depression that is tied to seasons of the year. Most people with SAD are depressed only during the late fall and winter (sometimes called the "winter blues") and not during the spring or summer. A small number, however, are depressed only during the late spring and summer.

SAD is most common in young adult women, although it can affect men or women of any age. In North America, SAD may affect as many as 6 of every 100 people, more in the Northern portions of the country than in the South. Another 10-20% of people may have a milder form of seasonal mood change.

Like all types of depression, SAD can have a devastating effect on a person’s life. Fortunately, almost all people with SAD can be helped with available therapies.

Seasonal Depression Causes

The exact causes of seasonal affective disorder (SAD) are unknown.

• Chemical changes in the brain caused by changes in the amount of sunlight are probably involved. People who live in geographical locations that are dark or cloudy during the winter are most likely to have SAD.

• A tendency to have SAD may run in some families.

Seasonal Depression Symptoms

Seasonal affective disorder (SAD) may have some of the same symptoms as other types of depression.

• Most people have only some of these symptoms, not all.
  
  
  • Depressed mood
  
  
  • Loss of interest in usually enjoyable activities
  
  
  • Fatigue or loss of energy
  
  
  • Feelings of worthlessness or hopelessness
  
  
  • Poor concentration, indecisiveness
  
  
  • Recurrent thoughts of death or suicide
    
• The symptoms of SAD come back every year, and for any specific person, they tend to come and go at about the same time each year.


• Winter SAD
  
  
  • Sleeping more than usual
  
  
  • Craving for sugar, starchy foods, or alcohol
  
  
  • Weight gain
  
  
  • Irritability
  
  
  • Conflicts with other people
  
  
  
  • Heaviness of arms and legs
  
  
  • Behavior disturbances (in children)
    
• People with winter SAD may seek out light places or sunlight, or like to have lots of artificial lights on.


• Summer SAD
  
• Insomnia


• Poor appetite


• Weight loss


• Agitation


• Anxiety

When to Seek Medical Care

Seek medical care if you think you have seasonal affective disorder or another type of depression, or if any of the following occur:

• Feelings of extreme sadness, hopelessness, or emptiness


• Inability to get out of bed or carry on normal activities


• Persistent loss of energy or increased need for sleep


• Unexplained change in appetite for food


• Changes in behavior that cause problems with family, friends, or work


• Feelings of wanting to die, wanting to commit suicide, or hurting yourself

Seasonal Depression Treatment

Self-Care at Home

The following activities or lifestyle changes may help prevent seasonal affective disorder or improve the symptoms:

• Spend at least 30 minutes outside every day.


• Set a timer on a light to go on early in the morning in the bedroom.


• Use a dawn simulator for a more naturalistic artificial dawn.


• Take daily walks outside.


• Increase indoor lighting with regular lamps and fixtures.

Medical Treatment

Bright-light therapy: This is exposure to bright artificial light, brighter than usual home or office lighting. Bright-light therapy relieves symptoms for about two thirds of people with seasonal affective disorder.

• Bright-light therapy products are available for sale and range in cost from $200-500. They range from 2,500-10,000 lux. Many experts recommend that 10,000 lux be used. Only devices that filter out harmful ultraviolet waves should be used. Types of devices include light panels or boxes, blankets, and visors.


• The bright-light source should be placed at eye level. Although staring at the light source is not recommended, the light must enter the eyes if it is to work. (Simple skin exposure does not work.) An approved bright-light therapy device should not harm the eyes if used as recommended.


• About 30 minutes of exposure to 10,000 lux each day is enough to relieve symptoms in most people. Others require greater exposure, as long as 45 minutes twice a day. You may need some trial and error to find the right amount. Your health care provider will guide you.


• Properly used, bright-light therapy has few side effects. A few people have reported eyestrain, headache, fatigue, irritability, sensitivity to light, or inability to sleep (only if therapy is used late in the day).


• Certain medications make you more sensitive to light. If you are taking any of these, you cannot use light therapy. Be sure to inform your health care provider of all the medications you are taking, including nonprescription medications and dietary supplements.


• Tanning beds should not be used for bright-light therapy as they do not filter out harmful ultraviolet waves.


• You may notice improvement in symptoms within a few days, or it may take as long as 3-4 weeks after starting therapy.

Medications

Antidepressant medications are useful for people who need further treatment because their symptoms improve only slightly or not at all with bright-light therapy. Most of these people are treated with antidepressant medication. To read more about antidepressants, see Understanding Antidepressant Medications

• The medications used most frequently are the selective serotonin reuptake inhibitors, or SSRIs (for example, Prozac and Zoloft).


• These agents may take 2-4 weeks to improve symptoms.


• Unwanted side effects depend on which medication is used. Your health care provider can tell you about side effects.


• Do not stop your medication abruptly. Stop or change dose only after consulting your health care provider.