Have we underestimated the possibility of bupropion sustained-release addiction?

To the Editor

Bupropion is a Food and Drug Administration (FDA) approved medication that has been widely used for the treatment of depressive disorders. Although there are biological bases for bupropion addiction, few amphetamine-like characteristics have been shown in humans. As an increasing number of studies are focusing on inappropriate bupropion use, especially via nasal insufflation, in specific populations, such as individuals in a correctional setting (Reeves and Ladner, 2013), the risk of addiction has been gaining importance. However, bupropion addiction in usual clinical settings has been seldom mentioned. Here, we present a case to highlight the possibility of bupropion sustained-release (SR) addiction.

The patient was a 27-year-old man with a 7-year history of depression. He had an unsatisfactory response to antidepressants combined with long-term individual psychotherapy. He complained of escitalopram-related sexual dysfunction, and therefore, escitalopram was switched to bupropion SR (150 mg twice per day). Three days after switching to bupropion SR, he reported that his mood improved and that he could look at his stress and depression from a new perspective immediately after taking bupropion SR, which helped him cope well with his depression. He insisted that he never had such experiences on taking other antidepressants, including extended-release formulation of bupropion, called bupropion XL, which releases bupropion at a slower rate than bupropion SR. Should we feel happy for the patient and consider that bupropion SR successfully treated his depression or be cautious?

The exact mechanism of the antidepressant action of bupropion is not known. However, evidence has proved that an increase in norepinephrine and dopaminergic neurotransmission can stimulate the central nervous system. Therefore, the mechanism of the antidepressant action of bupropion might involve norepinephrine and dopaminergic neurotransmission. The present patient’s response to bupropion SR reminded us of the clinical features of patients addicted to methylphenidate immediate-release (MPH-IR), which is a well-known dopaminergic stimulant (Hildt et al., 2015). Therefore, the present patient might experience bupropion SR addiction.

In conclusion, numerous patients with depression benefit from the inclusion of bupropion SR in the treatment protocol. Additionally, although MPH-IR has not been approved by the FDA, it has been gradually included in the augmentation strategies for treatment-resistant depression (Shelton, 2015). In the present report, we emphasize that the early improvement in depressive symptoms after the administration of dopaminergic-related stimulants should be cautiously considered treatment success and that psychiatrists should be aware of the possibility of addiction when dopaminergic drugs are administered for depression.