Due to prohibitively high drug cost, physicians were not prescribing the drug.

This is an observational study evaluating the safety and efficacy of dronabinol for the treatment of anxiety and/or depression in older adults. Participants who are prescribed dronabinol as part of a voluntary inpatient stay in McLean's Division of Geriatric Psychiatry will be interviewed about their mood and cognition on a weekly basis while on dronabinol.

Recently there has been renewed interest in potential alternative medical applications of cannabis/THC and medical marijuana is now legalized in 23 states and the District of Columbia. Acute effects of THC can include subjective feelings of euphoria, relaxation, and sedation, and clinicians noted that THC is well tolerated for its approved indications. Given these subjective effects and relatively benign safety profile, some physicians have used dronabinol (synthetic THC) "off-label" to treat depression and/or anxiety.

The investigators are doing this research to better understand how effective dronabinol treatment is when prescribed for depression and/or anxiety in older patients. The investigators also want to find out if dronabinol is safe to take without causing too many side effects. Dronabinol is is approved by the U.S. Food and Drug Administration (FDA) to treat loss of appetite in chemotherapy patients, but dronabinol is not approved by the FDA to treat depression and/or anxiety. Through research questionnaires on mood and cognition, the investigators can gather information that will help demonstrate how effective dronabinol treatment is at treating depression and/or anxiety.

Inclusion Criteria:

1. 50-89 years old (inclusive)
2. Inpatient on the Older Adult Unit in South Belknap 1 at McLean Hospital
3. Initiating dronabinol therapy for the treatment of any Diagnostic and Statistical Manual (DSM) 5 Major Depression or Anxiety Disorder Diagnosis
4. Ability to provide informed consent
5. Must be fluent in English

Exclusion Criteria:

1. Delirium as determined by the Confusion Assessment Method (CAM)
2. Serious or unstable medical illness, including cardiovascular, hepatic, renal, respiratory, endocrine, neurologic or hematologic disease, which might confound assessment of safety outcomes
3. Seizure disorder
4. Diagnosis of bipolar depression, Major depression with psychotic features, schizophrenia, schizoaffective disorder, dementia
5. Use of dronabinol or marijuana in the last year
6. Prescription of lithium or anticonvulsant medications (except gabapentin)
7. Patient currently admitted involuntarily to McLean Hospital

Subjects will be recruited from the Mood Disorder inpatient unit within the Division of Geriatric Psychiatry at McLean Hospital. These older patients will have a diagnosis of major depression and/or anxiety and have agreed to begin dronabinol treatment after recommendation by the attending physician.