Almost Half of Antidepressant Prescriptions Aren't Written for Depression

A whopping 45% of prescriptions for antidepressants are written for nondepressive reasons, recent research has revealed.

Jenna Wong, MSc, of McGill University, and her colleagues reviewed treatment indications for antidepressants and analyzed trends in antidepressant prescribing. They gathered data on prescriptions written for adults between January 2006 and September 2015 using an electronic health record and prescribing system used by primary care physicians in Quebec, Canada.

Of the total 101,759 prescriptions for antidepressants written by 158 physicians for 19,734 patients, only 55% were indicated for depression. The researchers found that the physicians also prescribed antidepressants to treat anxiety disorders (18.5%), insomnia (10%), pain (6%), and panic disorders (4%).

Although several classes of antidepressants, including selective serotonin reuptake inhibitors and tricyclic antidepressants, are also indicated to treat anxiety, the patients in the study who received an antidepressant for anxiety disorders didn’t have the depression indication noted on their medical record.

Notably, the physicians also prescribed antidepressants for several off-label indications, including migraines, vasomotor symptoms of menopause, attention-deficit/hyperactivity disorder, and digestive system disorders.

Several underlying factors could explain why off-label antidepressant prescribing is so pervasive.

“It isn’t clear how often physicians are completely aware of what they’re actually prescribing,” Wong explained to Pharmacy Times. “Many physicians incorrectly believe that all drugs within the same class have the exact same indication…but this is not the case.”

Therapeutic substitution is a controversial practice because of concerns relating to drug efficacy, adverse effects, drug interactions, and different indications for drugs despite being in the same class.

Wong also postulated that formulary restrictions could influence prescribing habits.

“The costs associated with prescribing a drug that doesn’t appear on a formulary may be prohibitive for some patients,” she explained. “Physicians might refrain from prescribing the most appropriate drug if it means savings for the patient, although it’s unclear how many times that decision is actually communicated to the patient.”

Although many health care providers acknowledge that off-label drug use can be appropriate in certain circumstances, it’s still important for pharmacists to let patients know that the risk for adverse events is higher when a medication is taken for an unapproved purpose.

In fact, one study found that patients prescribed drugs for indications that the FDA hasn’t approved face a 44% greater risk for adverse drug events.

Of note for pharmacists, the current study findings “indicate that the mere presence of an antidepressant prescription is a poor proxy for depression treatment,” the researchers concluded.

As medication experts, pharmacists should take the time to counsel patients about their condition and optimal treatment options.

The research letter appeared in the May 24/31, 2016, issue of JAMA.