Inclusion Criteria:

• Traumatic brain injury patients between 3 and 24 months post injury.

• Clear evidence/documentation of brain injury:

  i. documented/witnessed loss of consciousness, post traumatic amnesia ii. alteration in mental status (dazed/confused), and/or physical evidence of iii. trauma (MRI/CT hemorrhage/contusion)

• Traumatic brain injury with recovery to a Rancho los Amigos level 7 or 8 (alert and oriented).
• Meet criteria for DSM IV diagnosis Anxiety Disorder Due to a General Medical Condition.
• The symptoms of the anxiety disorder are not being controlled adequately with or without treatment at the time of referral.
• Military or Veteran beneficiary
• Men and non-pregnant/non-breastfeeding females
• Aged 18-65

Exclusion Criteria:

• Severe prior neurologic or psychiatric illness (based on DSM-IV criteria), such as stroke or psychosis. (Previous non-psychotic depression/anxiety is not an exclusion criterion)
• Current/prior unstable medical condition that could affect current brain function (ex. clear anoxic episode, cardiac arrest, current uncontrolled diabetes)
• Contraindication to the use of citalopram.
• Concomitant use of monoamine oxidase inhibitors (MAOIs), cimetidine, lithium, theophylline, digoxin, sumatriptan, warfarin, carbamazepine, triazolam, ketoconazole, CYP3A4 and 2C19 inhibitors, and metoprolol.
• Hypersensitivity to citalopram or any of the inactive ingredients in Celexa®
• Previous severe traumatic brain injury (defined as TBI with period of unconsciousness greater than 1 week. This exclusion refers only to TBIs prior to the current injury.
• Pregnancy (blood test required for females)
• Breastfeeding
• Current active suicidal ideation
• Inability to discontinue other psychotropic medications, such as tricyclic antidepressants or another SRI
• Current drug/alcohol abuse or dependence
• Previous unsuccessful trial of citalopram
• Participation in a concurrent drug or treatment trial