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
Other studies even suggest CBT-I in combination with imagery rehearsal therapy helps improve sleep-related PTSD symptoms. Imagery rehearsal therapy (IRT) is a modified cognitive behavioral therapy technique used to treat recurring nightmares. This technique involves recalling the nightmare, writing it down, modifying parts of the dream to make it positive, and rehearsing the new dream to create a cognitive shift that counters the original dream. IRT can be used for anyone suffering from recurring nightmares.