In the primary repression phase, 'it is highly probable that the immediate precipitating causes of primal repressions are quantitative factors such as...the earliest outbreaks of anxiety, which are of a very intense kind'.
1 A psychiatrist treats mood disorders, such as anxiety and depression, which can contribute to sleep problems. Psychiatrists may conduct therapy and prescribe medication to relieve symptoms.  A psychologist provides psychotherapy to treat mood disorders that can interfere with sleep.
A neurology doctor might work with an athlete to determine if they received any brain damage from a sports injury. A neurology doctor specializes in the diagnosis and treatment of disorders affecting the brain, spinal cord, and nerves. A general practitioner often refers the patient to a specific neurology or practice. A neurology doctor may perform reflex tests on patients.