Sleep Soundly Every Night, Feel Fantastic Every Day (29 page)

I treated her with sertraline, which regulated her serotonin levels and helped her stay asleep throughout the night. She mentioned that her symptoms came and went, usually growing worse during more stressful periods. I recommended that Susan continue psychotherapy so that she could manage stress more effectively.

Susan's symptoms are associated with another sleep-related eating disorder called night eating syndrome (NES). In NES the biological clock for eating, the circadian eating cycle, is out of phase with the circadian sleep–wake cycle. The sleep–wake cycle remains relatively normal, but the timing of eating is out of sync and results in an average of over 30% of caloric intake occurring after dinner. This has been verified by studies showing the secretion of hormones that suppress appetite being released at atypical times with regards to the 24-hour day.

While it is similar to SRED, this disorder is associated with

  
Daytime eating disorders, such as anorexia nervosa and bulimia

  
Hormonal and chemical imbalances

  
Mood disorders, such as bipolar

Those with NES often report evening hyperphagia—or an insatiable need to consume large quantities of food, which results in a lack of appetite for breakfast (morning anorexia). Between 30% and 50% of their daily caloric intake occurs after dinner, and they experience at least two of these nocturnal eating sessions a week. However, unlike SRED, NES does not usually involve ingesting inedible or dangerous substances.

Criteria for diagnosing NES were not formalized until 2008, during the First International Night Eating Symposium. Caloric intake and two nocturnal eating sessions are
considered to be the first indicators of NES. For a definitive diagnosis the person must also have at least three of the following symptoms.

1.
 
Lack of desire to eat in the morning or breakfast is omitted at least four times per week.

2.
 
A strong urge to eat after dinner and before going to bed. This desire may appear when the person wakes during the night.

3.
 
Insomnia at least four nights a week (the person either has trouble falling asleep or staying asleep).

4.
 
Must eat in order to fall or go back to sleep.

5.
 
Experience frequent depression or a worsening of mood toward the latter part of the day.

6.
 
The symptoms last at least three months.

7.
 
The symptoms cause significant interference with the person's life.

A primary diagnosis of NES means that the symptoms are not secondary to substance abuse or dependence, medical disorders, medication, or other psychiatric disorders.

There is evidence that NES is genetic and is usually a chronic condition characterized by early adult onset. Over the years the symptoms may wane, then flare up again when the person is under stress.

In addition to eating disorders, NES has been associated with depression, substance abuse, and anxiety. It also makes it difficult for a person to maintain a healthy weight or lose weight. It is especially dangerous for those trying to manage diabetes. Given NES's co-morbidity with other problems, I often recommend that the patient undergo psychotherapy and phototherapy (light therapy) to improve mood.

NES can be treated in some cases with effective antidepressants, such as sertraline (Zoloft), which raise serotonin levels. Two other treatments include cognitive behavioral therapy and properly timed light therapy. In the latter, a light box emits light at various levels of intensity, measured in lux, which is the amount of light a patient gets when sitting at specified distances from the light box. You would use a light box every day for the duration and intensity the doctor suggests. For instance, if starting with 15 minutes each day for several days, the duration increases to the amount of time discussed with the sleep doctor. Cognitive behavioral therapy was first used to treat the thoughts associated with the need to eat because researchers learned the following thought distinguished NES from SRED:
If I don't eat, I won't be able to fall asleep.
A behavioral therapy approach to weight loss is effective, as is progressive relaxation.

While SRED and NES are outwardly similar, there are a few other important distinctions.

Another way to differentiate the two is to think of SRED as primarily a sleep disorder that involves eating and NES as primarily an eating disorder that involves sleeping. In fact, the lack of research in this area is largely due to two groups of researchers—those who specialize in sleep disorders and those whose focus on eating disorders. The International Classification of Sleep Disorders has recently been revised to do away with the distinction. This may result in more thorough data collection because researchers will have a common objective.

 

Q.
 
At least three times a week, my wife goes to the kitchen during the night and eats. She has no recollection of doing this. When I awaken I often find open packages of sugar and candy on the counter. This seems to have started at about the same time she started a medication called Zyprexa for bipolar disorder. Do you think there could be a relationship?

A.
 
Yes, Zyprexa (olanzapine) is one of several medications that have been associated with SRED. This is an abnormal behavior arising out of sleep, referred to as a parasomnia. It is very similar to sleepwalking in that the higher brain
centers of the cortex are in a state of sleep while the brain stem is active. That is why there is frequently a complete amnesia for the event. Other medications that have been associated with this include Ambien (zolpidem), Halcion (triazolam), and lithium, as well as several other prescriptions for sleep medications and antipsychotics. I would definitely bring this to the attention of you health care provider.

Q.
 
I have been having some problems with sleeping. Recently my doctor put me on a medication called zolpidem. It has done wonders for my sleep. However, about once a week I find that I have been eating in my sleep. I have no recollection of this. Could this be due to the medication?

A.
 
Yes, quite likely. Zolpidem is the generic form of Ambien. Although an excellent sleep aid, an unfortunate side effect is SRED. In this disorder, people eat while they are actually asleep. It is a form of sleepwalking. I would bring this to the attention of your health care provider immediately. You will probably need to stop the medication.

Q.
 
What can be done about eating during the night while half-asleep?

A.
 
The key is whether you are actually asleep and have little or no recollection of going to the kitchen and eating, or are you awake but groggy when you are eating? The former is called SRED and is similar to sleepwalking. This can be caused by medications such as Ambien (zolpidem), as well as primary sleep disorders such as sleep apnea and RLS. Eliminating the offending medications or treating the underlying sleep disorder can treat this.
If you are unsure, I urge you to see a sleep specialist to work this out.

Q.
 
I have read about a disorder where people eat in the middle of the night. They say its like sleepwalking. I do most of my eating after bedtime, but I am awake. Is that the same thing?

A.
 
No, what you are describing is called NES. In this disorder people consume over 25% of their daily calories after 6:00 p.m. However, unlike SRED, which is done while sleeping, they are wide awake and conscious of what they are doing. The two are not synonymous. In your case you are describing NES. There are several behavioral and pharmacological treatments for this condition. In fact, several of the antidepressants that increase serotonin levels such as sertraline (Zoloft) and citalopram (Celexa) have been found to be particularly effective.

Repeatedly eating and drinking during the main sleep period, plus one or more of the following:

  
Eating strange combinations of food or even inedible things

  
Complaints of nonrestorative sleep, daytime fatigue, or somnolence