Fatigue, Sleep Disorders and Endocrine Abnormalities in TBI Patients

Inclusion Criteria: * Having moderate to severe TBI at least 3 months prior to enrollment. This can be demonstrated by a history of loss of consciousness, amnesia or another neurologic deficit after brain injury * Be between the ages of 18 and 70 years Exclusion Criteria: * History of prior TBI, stroke, seizures, severe psychiatric disturbances (i.e., those known to influence memory performance, such as schizophrenia, bipolar disorder), or drug abuse will be excluded. * Pregnant, nursing, or planning pregnancy during the study period. * Dementia * Other neurological conditions which are associated with aging and known to cause fatigue (e.g. Parkinson's Disease)