Adding a second-generation antipsychotic to an antidepressant to treat depression carries an increased mortality risk for middle-aged adults, results of a large, observational study show.
“Our study suggests physicians should consider prescribing antipsychotics to adults with depression carefully, as the potential health risks are substantial and the benefits are quite modest and controversially debated,” lead investigator Tobias Gerhard, PhD, Center for Pharmacoepidemiology and Treatment Science, Rutgers University, New Brunswick, New Jersey, said in a news release.
The results, he added, “emphasize the importance of considering newer antipsychotics only after non-response to less risky, evidence-based treatment options has been established.”
The study was published online September 30 in PLOS ONE.
A Last Resort
Previous research has demonstrated an increased mortality risk for elderly patients with dementia who take an atypical antipsychotic, but it’s unclear whether this risk occurs among nonelderly adults who use newer antipsychotics as augmentation treatment for depression.
To investigate, Gerhard and colleagues analyzed national healthcare claims from the Medicaid program from 2001 to 2010 for 39,582 Medicaid beneficiaries (mean age, 44.5 years; 78.5% women) who had been diagnosed with depression. Patients with alternative indications for antipsychotic therapy, such as schizophrenia, psychotic depression, or bipolar disorder, were excluded.
After at least 3 months of treatment with a single antidepressant, for more than half of the patients (56.6%), treatment was augmented with an atypical antipsychotic (quetiapine, risperidone, aripiprazole or olanzapine). For the remainder (43.4%), a second antidepressant was added.
The average chlorpromazine equivalent starting dose for all atypical antipsychotics was 68 mg/d. The dose was increased to 100 mg/d during follow-up.
A total of 153 patients died during 13,328 person-years of follow-up, including 105 for whom treatment was augmented with an atypical antipsychotic and 48 for whom treatment was augmented with a second antidepressant.
Compared to those who received a second antidepressant, among those for whom an antipsychotic was added, there was a 45% increased risk of dying during follow-up (adjusted hazard ratio, 1.45; 95% CI, 1.02 – 2.06).
This equates to an absolute risk difference of 37.7 deaths per 10,000 person-years of treatment (0.38% per year) and a number needed to harm of roughly 265 per year. For higher-risk subgroups, the number needed to harm decreased substantially, the authors note. The results were robust across several sensitivity analyses.
“We don’t know the mechanisms of the increased mortality risk, but cardiac and infectious causes are leading candidates,” said Gerhard.
“Our study in nonelderly adults with depression did not identify a single predominant cause of death. However, this may be a result of both the relatively small number of deaths in our study as well as of the well-recognized concerns regarding the accuracy of cause-of-death attribution in death certificates,” Gerhard said.
“As with the potential causes of death, the pathophysiological pathways involved are not well understood but could, among others, involve adverse metabolic effects, including weight gain, diabetes, dyslipidemia, QT prolongation, sedation, and falls ― all of which have been associated with at least some of the newer antipsychotics,” he added.
The researchers state that atypical antipsychotics should only be considered “after non-response to evidence-based treatment options that are less risky.”
Another Red Flag
Commenting for Medscape Medical News, Timothy Sullivan, MD, chair of psychiatry and behavioral sciences at Northwell Health’s Staten Island University Hospital in New York City, said this is a “valid contribution” and represents the second large study that “raises the same concern.”
“We’ve been probably underestimating the risk in administering them, and that’s something people really need to know, because if you’re prescribing it for someone with mild to moderate depression, it may be helpful, but is it really worth the risk if you’re significantly increasing their risk of death?” said Sullivan, who wasn’t involved in the study.
Clearly, he said, this “raises a flag that we have to look at this a little more carefully and be a little clearer with patients about the risk. One could argue that we should not be so quick to add these drugs, even though they could be helpful, before we exhaust other less potentially risky options.”
Sullivan’s advice: “Do the three trials of antidepressants, look at antidepressant combinations, don’t be quick to jump to this particular option, because of the concerns. Certainly there are situations like psychotic depression where the risk of use is outweighed by the benefits, given the clinical syndrome, but for less severe forms, we probably should reformulate some of our algorithms.”
The study was supported by the National Institute of Mental Health (NIMH). Gerhard received grants from the NIMH and the National Institute on Aging during the conduct of the study; grants and personal fees from Bristol-Myers Squibb; and personal fees from Eisai, Merck, Pfizer, Lilly, and IntraCellular Therapies outside the submitted work. Sullivan has disclosed no relevant financial relationships.
PLoS One. Published online September 30, 2020. Full text