It is unclear if ketamine — administered by IV, orally, or by intramuscular injection — is effective for treatment-resistant depression.
The studies we found on ketamine for treatment-resistant depression suggest that ketamine could lead to an immediate improvement in depressive symptoms. None of the studies, however, had a long enough follow-up period to determine if the effects last beyond a few weeks.
It is unclear if ketamine is an effective treatment for PTSD.
We found 2 studies on ketamine for PTSD. One study found that IV ketamine infusions were more effective than midazolam infusions at improving PTSD symptoms. The other study, which was on the military population, found that IV ketamine infusions were not effective compared with placebo.
For treatment-resistant depression or PTSD, ketamine appears to be safe and tolerable, with short-lived side effects — the most frequent being dissociative symptoms and cardiovascular changes (e.g., increased blood pressure and heart rate).
The Canadian guideline recommends that IV ketamine be used as a third-line treatment for adults with treatment-resistant depression, and the guideline from Denmark recommends against using IV ketamine for treatment-resistant depression.
No guidelines were found on the use of ketamine to treat PTSD.