Depression is one of mankind’s oldest brain disorders. Major depressive disorder (MDD) is the most common psychiatric disorder in the world, affecting approximately 17% of the population in developed areas at any given time. The World Health Organization ranks depression third among the leading causes of global disease burden.
In 2017, the National Institute of Mental Health estimated 17.3 million adults, or 7.1% of the U.S. population, suffered at least one episode of major depression. Of those affected, 11 million, or 4.5% of the population, suffered at least one major depressive episode with severe impairment, defined as episodes that interfere with or limit one’s ability to carry out major life activities. In other words, approximately 64% of U.S. adults with major depression suffer severe impairment in their ability to function yearly! Typically, persons who develop MDD do not seek help for weeks or months after developing symptoms, perhaps in part because of a widely held belief that typical treatments are minimally effective at best.
Traditionally, MDD treatment is limited to the use of medications that act on the monoamine neurotransmitter systems (dopamine, norepinephrine, and or serotonin). Unfortunately, these medications can take weeks to months to have an effect, and their efficacy is variable and often incomplete. It is estimated that only 33% of individuals have a response to their first medication, while 66% of patients suffer treatment-resistant depression (TDD), with variable response only after trials of several classes and combinations of antidepressants and adjunctive therapies. These patients frequently require inpatient hospital treatments and electroconvulsive therapy (ECT) for control of their symptoms. As a result, it may take many months for patients with TDD to obtain any relief.
In the interim, these patients can develop worsening depression, hopelessness, and despair complicated by withdrawal, substance abuse, and suicidality. Patients with bipolar depression (BD) may face an even more dismal reality. Lithium is the only drug specifically indicated for BD, and may only incompletely treat the condition. As a result, the majority of patients with BD are managed through polypharmacy with antidepressants, anticonvulsants, and antipsychotic medications with or without lithium, again with long periods of time to attain response, variable efficacy, and high incidences of untoward side effects. Many patients with BD are treatment resistant, and suffer from complications of substance abuse and suicide. Clearly, a more rapid and effective therapy for depressive disorders is necessary.
Ketamine infusion therapy has proven to be rapidly effective in providing remission of depressive symptoms of MDD, TDD, and BD, in some cases providing temporary relief within hours of the first infusion. It has been shown to be remarkably effective in aborting suicidal ideations with a single IV infusion. Ketamine has been shown to be 70% effective in TDD. Although, the response to a single infusion is short-lived (matter of days), repeat administration over a short period of time (typically two weeks) can extend the length of remission, with some patients enjoying improvement for as long as six months. Additional “booster” treatments can be given that continually extend the length of remission of symptoms. Ketamine infusions have been shown to be safe, rapid, and effective. Consequently, ketamine infusion therapy is revolutionizing the treatment of depressive disorders.