Ketamine May Alleviate Bipolar Depression, Too
Some months back, I wrote a blog post about researchers using the ketamine as a fast acting treatment for depression. Recently I was alerted to another study by the same core researchers from the National Institute of Mental Health (NIMH) using ketamine to treatment depression in people with bipolar disorder (Zarate et al., 2012). The study was a replication of a similar study published a few years ago (Diazgranados et al., 2010).
It’s still just ketamine for depression
In this study, ketamine wasn’t used to treat bipolar disorder as a whole. Rather, ketamine was used to treat depressive symptoms in people with bipolar disorder who were currently depressed. The people in the study were also maintained on mood stabilizers to help manage bipolar mania and hypomania.
Otherwise, the procedure and findings were similar to the other studies. People were randomly assigned to receive two infusions of either ketamine or a placebo (saline). The infusions took about 40 minutes, and the second infusion took place 2 weeks after the first.
Most people who received ketamine (79%) felt less depressed, but no one who received the placebo showed improvements. I should note, though, that it was probably pretty obvious to people who received the placebo that it was not ketamine, as ketamine is a powerful psychoactive with obvious psychological effects. In contrast, saline isn’t likely to cause a detectable physiological response.
The treatment is still very experimental
After my earlier post was published, I received calls from a few people looking for ketamine treatment in Oregon. I’m afraid ketamine is still very much an experimental treatment, and no one, to my knowledge, is using it outside of well-controlled research studies. The only studies I’ve come across were conducted by NIMH researchers in Bethesda, Maryland.
The caveats I discussed in my previous post about the feasibility of ketamine for treating depression remain the same. At this point, we’re still not sure what the long-term effects are of using ketamine for depression. Given that it’s so fast-acting and is already a club drug, there is some potential for abuse and addiction.
Ketamine might be a useful intervention for people who are acutely depressed and acutely suicidal. In this respect, I remain cautiously optimistic, as it could reduce costly inpatient stays.
I’m skeptical, though, that ketamine will prove to be a cure-all wonder drug. For example, a newer study found that people treated with ketamine relapse into depression in an average of 2 weeks (Ibrahim et al., 2012). Although ketamine is safely used as an anesthetic in surgical procedures, we don’t know the impact of frequent doses across an extended period of time.
The newer research I cite in this post doesn’t take any steps towards answering questions about ketamine’s effectiveness beyond a few weeks, but it does suggest that people with bipolar disorder who are in a state of deep depression might find quick, if not enduring, relief from depression.