which chance and bias, including confounding, could be ruled out with reasonable confidence as an explanation for the observed association.

  • Penetrating TBI and decline in neurocognitive function associated with the region of the brain affected and the volume of brain tissue lost.

  • Penetrating TBI and long-term unemployment.

  • Severe TBI and neurocognitive deficits.

  • Moderate or severe TBI and dementia of the Alzheimer type.

  • Moderate or severe TBI and parkinsonism.

  • Moderate or severe TBI and endocrine dysfunction, particularly hypopituitarism.

  • Moderate or severe TBI and growth hormone insufficiency.

  • Moderate to severe TBI and long-term adverse social-function outcomes, particularly unemployment and diminished social relationships.

  • Moderate or severe TBI, in the subset of patients who are either admitted into or discharged from rehabilitation centers or receive disability support, and premature death.

  • TBI and depression.

  • TBI and aggressive behaviors.

  • TBI and postconcussion symptoms (such as memory problems, dizziness, and irritability).

  • Professional boxing and dementia pugilistica.

Limited/Suggestive Evidence of an Association

Evidence is suggestive of an association between TBI and a specific health outcome in human studies but is limited because chance, bias, and confounding could not be ruled out with reasonable confidence.

  • Moderate or severe TBI and diabetes insipidus.

  • Moderate or severe TBI and psychosis.

  • Moderate TBI and neurocognitive deficits.

  • Mild TBI resulting in loss of consciousness or amnesia and unprovoked seizures.

  • Mild TBI and ocular and visual motor deterioration.

  • Mild TBI with loss of consciousness and dementia of the Alzheimer type.

  • Mild TBI with loss of consciousness and parkinsonism.

  • Mild TBI and posttraumatic stress disorder in Gulf War military populations.

  • TBI and decreased alcohol and drug use in the 1–3 years after injury.

  • TBI and completed suicide.

Inadequate/Insufficient Evidence to Determine Whether an Association Exists

Evidence is of insufficient quantity, quality, consistency, or statistical power to permit a conclusion regarding the existence of an association between TBI and a specific health outcome in humans.

  • Moderate or severe TBI and brain tumor.

  • Mild, moderate, or severe TBI that is survived for 6 months or more and premature death.

  • Mild TBI and neurocognitive deficits.

  • Mild TBI (without loss of consciousness) and dementia of the Alzheimer type.

  • Mild TBI and posttraumatic stress disorder in civilian populations.



The National Academies | 500 Fifth St. N.W. | Washington, D.C. 20001
Copyright © National Academy of Sciences. All rights reserved.
Terms of Use and Privacy Statement