A sleep disorder can be described as a condition in which a patient is afflicted with disturbance in the amount, timing or quality of their sleep. This disturbance would be a persistent problem that affects the patient’s social or occupational functioning and would cause a significant amount of emotional distress. There are approximately seventy different sleep disorders, including: sleepwalking, narcolepsy, insomnia and snoring.

The cognitive approach to psychology is based on several assumptions about the human brain. these assumptions are that humans do not passively respond to their environment; cognitives processes actively organise and manipulate the information we receive; internal mental processes are important in understanding behaviour;