01/14/2014 10:28 am ET Updated Mar 16, 2014

Narcolepsy Drug Shows Promise in Depression Treatment

On the heels of recent news that insomnia treatment can increase the likelihood of remission and recovery from depression comes another discovery indicating that a form of sleep therapy may have a significant positive impact on treatment for depression. Researchers in Britain are reporting that the drug modafinil, used to treat sleep disorders -- most often narcolepsy and sometimes sleep apnea and shift work sleep disorder, can help alleviate the severity of depression and some of its symptoms when used in combination with anti-depressant medications.

A team of scientists from several universities in England investigated the effectiveness of modafinil as a supplemental therapy for depression in patients with two forms of depression: major depressive disorder and bipolar depression. Researchers examined the results of already completed studies that had included modafinil as a supplemental treatment for depression, used in conjunction with anti-depressant medication. They ultimately evaluated data from six clinical trials that included a total of 910 patients, including 568 with major depressive disorder and 342 with bipolar depression.

Their analysis revealed that patients who took modafinil in addition to anti-depressants were more likely to experience significant improvements to their depression, and more likely to enter remission. This was true for both major depressive disorder and for bipolar depression. In addition to lessening the severity of depression and increasing rates of remission, the use of modafinil also resulted in improvements to fatigue.

Fatigue and difficulties with sleep are common problems for people who suffer from depression. Sleep problems are no longer considered only a symptom or consequence of depression, but are now also recognized as a risk factor for the mood disorder. Research indicates that a significant majority of people with depression also suffers from disrupted and poor quality sleep. Insomnia is a frequent complaint among people with depression, with symptoms including difficulty falling asleep, difficulty staying asleep, waking extremely early and feeling tired and unrefreshed by sleep.

Hypersomnia -- a pattern of excessive daytime sleepiness, difficulty waking, and extended periods of sleep -- is another common sleep disorder for people with depression. Depressed patients with sleep problems are more likely to experience complications to their treatment. Their symptoms tend to be more disruptive, and they are more likely to suffer relapses than patients without sleep problems. People who are both depressed and struggling with sleep are also at significantly higher risk for suicide.

The drug modafinil is most often prescribed to treat narcolepsy, a sleep disorder that's characterized by excessive daytime sleepiness and episodes of urgent, uncontrollable need to sleep. Modafinil is a type of drug known as a wakefulness-promoting agent, and it works by altering neurotransmitter activity in the brain to decrease sleepiness and fatigue and to increase alertness.

Researchers in the current study believe that modafinil's effects on the brain's neurotransmitter system may be the reason the drug appears to alleviate the symptoms of depression and reduce the severity of the disease, when used in combination with other anti-depressant therapies.

There are several different neurotransmitters in the brain that control sleep and wakefulness. There also exists within the brain a significant neurological overlap between sleep and mood. Some of the same neurotransmitters that influence sleep -- including serotonin -- also are believed to play an influential role in the risks, course, and severity of depression.

This new research is the latest in a series of breakthroughs related to the effectiveness of treating depression with sleep therapies. In November 2013, we learned of results from a study sponsored by the National Institute of Mental Health (NIMH), which found treating insomnia symptoms among people with depression dramatically increases the likelihood of recovery. Researchers found that incorporating a form of treatment known as cognitive-behavioral therapy for insomnia, or CBT-I, nearly doubled rates of recovery from depression. CBT-I is a type of talk therapy that focuses on emotional and behavioral issues related to sleep. The NIMH study is the first in a group of four research projects investigating the role of sleep problems in the treatment of depression. We're awaiting results of the remaining three studies, which are expected in 2014.

Nearly 20 million adults in the United States suffer from depression, and more than 350 million people worldwide are coping with the condition. It's a medical condition that can often be disruptive to quality of life, to productivity and work, and also to overall health. The most common therapies for depression are psychotherapy and anti-depressant medications, frequently a class of drug known as selective serotonin reuptake inhibitors, or SSRIs. (This type of medication is also used to treat sleep problems such as insomnia.)

The use of talk therapy and medication, either individually or together, are considered the most effective course of treatment for patients with depression. But successful treatment is far from guaranteed. Research shows that most anti-depressant medication is not significantly more effective in treating depression than placebo. Even when medication is used in combination with psychotherapy, research indicates a third or more of patients do not experience meaningful improvement to their condition.

A shift toward including sleep therapy as part of standard treatment for depression stands poised to make a profound change in how we deal with depression, and with it a significant improvement for many the many patients who aren't finding sufficient remedy in current therapies.

We still have much to learn about how both sleep disorders and depression influence on another. But recent scientific discoveries may have brought us to a turning point, where attention to sleep and treatment for sleep problems will begin to be regarded as part of the core treatment for depressive disorders. That's an important step, one that could bring new levels of relief for millions of people.

Sweet Dreams,
Michael J. Breus, PhD
The Sleep Doctor®

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