to be rigorously explored, but the efficacy of cbt-i for major depressive disorder and bipolar disorder looks promising. application to post-traumatic stress disorder post-traumatic stress disorder (ptsd) is an anxiety disorder that may develop after a person experiences a traumatic event. many people with ptsd relive or re-experience a traumatic event; memories of the event can appear at any time and the person feels the same fear/horror as when the event occurred. these can be either in the form of nightmares and/or flashbacks. those with ptsd also experience hyperarousal (fight-or-flight) and can be too alert to go to sleep. due to this, many experience some form of insomnia. recent studies have shown that cbt-i offers some improvement for those with ptsd. for example, a study conducted in 2014 looked at whether cbt-i improved sleep in those with ptsd along with other ptsd related symptoms. the study showed improved sleep and improved psychosocial functioning. other studies even suggest that 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. application to other conditions individuals with cancer often experience insomnia due to psychological, behavioral or physical consequences of cancer diagnosis and treatment. cbt-i has been shown to be an effective treatment in such individuals. furthermore, it may also improve their mood, fatigue and overall quality of life. cbt-i can also be applied to patients with both chronic pain and insomnia. chronic pain can directly contribute to the difficulties in initiating and maintaining sleep via hyperarousal due to the experienced pain. cbt-i has been shown to improve sleep continuity and reduce impairment in daily functioning due to pain in such individuals. cbt-i has been shown to be effective in geriatric patients with insomnia as well. medication might be problematic in such patients and they might prefer psychotherapy over medication. therefore, it should be considered as a treatment option for them. efficacy patients who have undergone cbt-i spend more time in sleep stages three and four (also known as slow-wave sleep, delta sleep or deep sleep) and less time awake than those treated with zopiclone (also known as imovane or zimovane). they also had lasting benefits according to a review six months later, whereas zopiclone had no lasting results. when the common hypnotic drug zolpidem (more commonly known as ambien) was compared with cbt-i, the latter had a larger impact on sleep-onset insomnia. cbt-i by itself was no less effective than cbt-i paired with ambien. for a thorough review of cbt-i and its effectiveness, see the morin, bootzin, buysse et al. article referenced below. computer-based cbt-i was shown to be comparable in effectiveness to therapist-delivered cbt-i in a placebo-controlled clinical study. a meta-analysis showed that adherence and effectiveness are related in technology-mediated sleep treatment.