New Treatment for Bipolar Depression – Ketamine

Bipolar depression is notoriously hard to treat in some individuals with bipolar disorder—particularly in those with bipolar II. In fact, people with bipolar II spend 35 times more time depressed than hypomanic. This suggests that bipolar II is primarily a depressive disorder.

In spite of this, only two treatments are approved for the treatment of bipolar depression: quetiapine (Seroquel) and olanzapine/fluoxetine combination (Symbyax). Naturally, doctors use many other medications to treat bipolar depression, but still, many people are treatment resistant to all treatments, for some even including the most effective known treatment–electroconvulsive therapy (ECT).

Ketamine

Enter ketamine. Ketamine is a hydrochloride salt and is pharmacologically classified as an NMDA (N-methyl d-aspartate) receptor antagonist. Ketamine is an anaesthetic most commonly used in veterinary medicine although is used as in humans frequently as well. And yes, ketamine is a recreational drug (“K”) and can induce hallucinations in some doses.

Now, if you were to ask me if we should be trying out anaesthetics or horse tranquilizers as antidepressants, I would suggest that isn’t the best use of resources, but in this case, I would be wrong.

Ketamine for Bipolar Depression

Initially, ketamine showed promise in the treatment of unipolar depression but that was closely followed by testing in bipolar depression wherein it also shows promise. Only 163 patients with depression have been given ketamine thus far but its success rate ranges from 25-85 percent at 24-hours post-infusion. (The numbers vary significantly as researchers try to ascertain the best infusion dose to be given over what period of time.)

In other words, people feel better in less than a day after being given one dose of ketamine. (Actually, its antidepressant onset happens in as little as two hours.)

No one knows exactly why ketamine works as a fast-acting antidepressant but one of the reasons may be its action on the neurotransmitter glutamate. Glutamate has been a major new area of research in the search for antidepressants with a novel mechanism of action. (I, personally, feel that glutamate modulators are the wave of the antidepressant future, but that’s me.)

Limitations of Ketamine Research

Unfortunately, studies on ketamine are small because it requires hospitalization of the patient. It’s likely once we work out the kinks of the treatment, this won’t be needed, but right now for the safety of the study participants they are monitored in-hospital for side effects.

Likely, if ketamine treatments were to be up and running they would be like electroconvulsive therapy (ECT) sessions where people would go to a hospital/clinic for their treatment, be there for a few hours, and then could go home.

Keep in mind that ketamine is given through an intravenous infusion and this infusion is critical for the ketamine to work—taking street ketamine will not yield antidepressant effects.

Early Days in Ketamine Research

Admittedly, it’s early days in ketamine research, but I’m extremely hopeful about this development as it’s a treatment that may work for those whom nothing else has. Moreover, ketamine works in a unique way which offers patients greater options when trying out antidepressants. Additionally, because ketamine is already used in medicine, I think its approval process would likely be shortened, offering this treatment to the public more quickly (although I could be wrong about that).

Yes, it could be so expensive to be out of reach for many, but that is the nature of new drugs. Nevertheless, more choices means more successfully treated people and I’m excited about that.