Sleep disturbances are an evident factor in psychiatric disorders. Generally, these disorders include depression; generalized anxiety disorder; panic disorder; post-traumatic stress disorder; schizophrenia; and Alzheimer’s, which, despite being a neurodegenerative disease, can develop with depression or sleep disorders. Patients with psychiatric disorders often complain of difficulty initiating and maintaining sleep (in other words, initial and maintenance insomnia), and non-restful and interrupted sleep.