Individuals who have difficulty initiating or maintaining sleep can be classified as having either primary or comorbid insomnia. Primary insomnia is sleeplessness that is not associated with another medical or psychological condition. This could arise as a result of prolonged periods of stress, from abnormalities in the neurological control of the sleep-wake cycle involving areas of the brain responsible for wakefulness and sleep, or due to the individual complaining of insomnia without any objective evidence of any sleep disturbance. For comorbid insomnia, the individual’s sleep problems are associated with other health conditions (depression, cancer, arthritis), chronic pain, medication or substance abuse e.g. alcohol.
Primary insomnia may not necessarily require drug treatment and could be managed by patient focused therapy involving careful assessment and cognitive behavioural therapy for insomnia (CBTi). Comorbid insomnia may require treatment of the associated condition, e.g. pain or depression, but there is good evidence that it will also respond to psychological therapy. Treatment of comorbid insomnia therefore involves treating the health condition that is associated with the insomnia but also using CBTi to treat the insomnia itself.