context: Depression is a mood disorder that is characterized by sadness or feeling blue along with a series of physical symptoms such as low energy, disrupted sleep, and appetite changes. Nearly everyone feels normal sadness or feels down from time to time. Sometimes, however, the sad feelings become intense, last for long periods of time, and involve other physical symptoms that prevent a person from leading a normal life. These feelings often lead to a medical diagnosis of clinical depression. An inability to sleep, insomnia, or excessive oversleeping called "hypersomnia" can be one of the signs of depression. Lack of sleep alone is not the same thing as depression, but it can be one of its important symptoms. Lack of sleep caused by another medical illness or by personal problems can also lead to daytime fatigue and make the diagnosed depression worse. An inability to sleep that lasts over a long period of time is also an important clue that someone may be depressed. Usually, once the depression has been successfully treated, symptoms of insomnia will improve. Treatment choices for depression depend on how serious the illness is. The most effective treatment for depression for most people is often a combination of psychotherapy (counseling or talk therapy) and medication. Medication tends to work more quickly to decrease symptoms while psychotherapy helps people learn coping strategies to prevent the onset of future depressive symptoms. Psychotherapy can also address coping skills to improve a person's ability to fall asleep. Doctors may sometimes treat depression and insomnia by prescribing an SSRI (selective serotonin reuptake inhibitor) or other antidepressant along with a sedating antidepressant or with a hypnotic medication (medication that helps people sleep). Antidepressants include: SSRIs like citalopram ( Celexa), fluoxetine ( Prozac), paroxetine ( Paxil), and sertraline ( Zoloft). These medications can perform double duty for patients by helping them sleep and elevating their mood, though some people taking these drugs may have trouble sleeping. For some people, however, SSRIs can cause insomnia and are therefore usually prescribed in the morning, sometimes with an additional medicine on a short-term basis to help people sleep at night. SNRIs (serotonin and norepinephrine reuptake inhibitors) like desvenlafaxine ( Pristiq, Khedezla), duloxetine ( Cymbalta), levomilnacipran ( Fetzima), and venlafaxine ( Effexor). These medicines affect two neurotransmitters (brain chemicals) thought to be involved in depression -- serotonin and norepinephrine -- and are sometimes favored when an SSRI is not effective or when depression occurs with other problems such as pain disorders or certain forms of anxiety. Tricyclic antidepressants such as amitriptyline ( Elavil) and nortriptyline ( Pamelor). Sedating antidepressants such as Trazodone, mirtazapine ( Remeron), and Silenor. Hypnotics include: Ambien/ Ambien CR (zolpidem) Sonata (zaleplon) Lunesta (eszopiclone) Restoril (temazepam) Serax ( Oxazepam) The over-the-counter hormone melatonin also is sometimes recommended for insomnia or sleep disrupted by depression. A prescription drug called Rozerem (ramelteon) binds to the same brain receptor as melatonin and is another medication strategy for treating insomnia. Another unique sleep drug is called Belsomra (suvorexant). It's the first approved drug in a class called orexin receptor antagonists. In addition to trying medications, here are some tips to improve sleep: Learn and practice relaxation and deep breathing techniques. Clear your head of concerns by writing a list of activities that need to be completed the next day and tell yourself you will think about it tomorrow. Avoid daytime naps, which may just rob you of your night time "sleep debt." Get regular exercise no later than a few hours before bedtime. Do not spend time looking at television or looking at computer screens before bedtime because the light emission from display screens can interfere with the release of the brain chemical melatonin, which is a signal to the sleep centers in the brain that it is time for bed. Don't use caffeine, alcohol, or nicotine in the evening. Don't lie in bed tossing and turning. When you can't sleep, go into another room and do something relaxing. When you start feeling like you may be able to sleep, get back in bed. Use the bed only for sleeping and sexual activity. Don't lie in bed to watch TV or read. This way, your bed becomes a cue for sleeping, not for lying awake.