SAN FRANCISCO — The goal of antidepressant treatment should be remission, but most clinical trials use a 50% response in 50% of patients as the criterion for effectiveness. Only about 20%–30% of patients achieve complete remission, and this suggests that additional treatment will be necessary, Jeffrey M. Levine, M.D., said at the annual meeting of the American College of Physicians.
But before changing a patient's selective serotonin reuptake inhibitor (SSRI) prescription because of an incomplete response, physicians should consider a series of questions, said Dr. Levine of the Albert Einstein College of Medicine, New York.
First, determine whether the patient is taking the medication. Studies indicate that about 50% of SSRI prescriptions are filled only once. In addition, find out whether the patient is using alcohol or illicit drugs.
Next, use this as an opportunity to review relevant medical issues. Has the patient had recent thyroid function and HIV tests? Is he or she taking any other medications, such as glucocorticoids, β-blockers, or fluoroquinolones that could affect depression treatment? Has the patient been evaluated for sleep apnea?
It may be productive to employ the systematic approach suggested by the mnemonic CITTENNS for possible causes of altered mental status. CITTENNS stands for cardiorespiratory, infectious, toxic, traumatic, endocrine/metabolic, neurologic, neoplastic, and systemic/autoimmune.
Ask about domestic violence, ongoing safety issues, or threats to the patient. “If a patient is being abused or threatened by a partner, your antidepressants are not going to make [him or her] better,” Dr. Levine said.
Consider whether the patient may have something to gain from depression. “If a patient has a comp case or a disability case going at this moment, it may be irrelevant or it may be very relevant.” Dr. Levine said. “It may just not be the time they're going to get better.”
Consider the possibility that the patient has bipolar disorder. Although it may seem as if it would be difficult to confuse mania with depression, recent studies have shown that about a third of patients with bipolar disorder are depressed at the time they're manic. In this mixed state, the patient may complain about depression but have features of mania, such as agitation, pressured speech, racing thoughts, and an inability to sleep.
If the physician answers all of those questions to his or her satisfaction, and the patient still has an incomplete SSRI response, the patient should be given a trial at the maximal dose: 40–60 mg of fluoxetine, 150–200 mg of sertraline, 40–50 mg of paroxetine, or 20 mg of escitalopram, for example.
If that doesn't work, there's little point in trying a different SSRI. Instead, one should either switch to a combined serotonin norepinephrine reuptake inhibitor such as venlafaxine or duloxetine, or add bupropion or mirtazapine.
Bupropion is contraindicated in patients with eating disorders or a history of seizures, but may be especially useful in the patient who reports a lack of energy.
Mirtazapine can increase appetite and cause weight gain, which may or may not be desirable, and has a strong sleep-enhancing effect.
If the addition of a norepinephrine agent doesn't work, the next step would be a low dose of a second-generation antipsychotic such as 0.5–2 mg of risperidone or 5–15 mg of olanzapine. This step is problematic for patients who have type 2 diabetes or are at risk for this condition.
In patients with possible bipolar disorder, lithium or lamotrigine can be useful.
Finally, electroconvulsive therapy might be considered in patients with persistent psychosis, continued suicidality, profound psychomotor retardation, or profound anhedonia.
Dr. Levine disclosed serving on the speakers' bureau for Pfizer Inc.