Insomnia
While insomnia is a common symptom of depression, antidepressants are effective for treating sleep problems whether or not they are associated with depression. While all antidepressants help regulate sleep, some antidepressants such as amitriptyline, doxepin, mirtazapine, and trazodone can have an immediate sedative effect, and are prescribed to treat insomnia. Amitriptyline and doxepin both have antihistaminergic, anticholinergic, and antiadrenergic properties, which contribute to both their therapeutic effects and side effect profiles, while mirtazapine's side effects are primarily antihistaminergic, and trazodone's side-effects are primarily antiadrenergic. Mirtazapine is known to decrease sleep latency (i.e., the time it takes to fall asleep), promoting sleep efficiency and increasing the total amount of sleeping time in people with both depression and insomnia.
Cognitive behavioral therapy for insomnia
Sleep restriction is probably the most controversial step of CBT-I, since it initially involves the restriction of sleep. Insomniacs typically spend a long time in bed not sleeping, which CBT-I sees as creating a mental association between the bed and insomnia. The bed therefore becomes a site of nightly frustration where it is difficult to relax. Although it is counterintuitive, sleep restriction is a significant and effective component of CBT-I. It involves controlling time in bed (TIB) based upon the person's sleep efficiency in order to restore the homeostatic drive to sleep and thereby re-enforce the "bed-sleep connection". Sleep Efficiency (SE) is the measure of reported Total Sleep Time (TST), the actual amount of time the patient is usually able to sleep, compared with his or her TIB.