Researchers from Emory University in Atlanta, Georgia, found that treatment guidelines recommending either evidence-based psychotherapy or antidepressant medication for nonpsychotic major depression can be effective in treatment-naive patients, regardless of treatment preferences. The findings were published in The American Journal of Psychiatry.1
The researchers studied 344 participants aged 18 to 65 years as part of the PReDICT study (Predictors of Remission in Depression to Individual and Combined Treatments; ClinicalTrials.gov ID: NCT00360399), which aimed to identify clinical and biological factors that would be predictive of treatment outcomes in patients with major depressive disorder who had not yet been treated.
Following identification of preferred treatments, the participants were randomly assigned to either 12 weeks of escitalopram (10 to 20 mg/d), duloxetine (30 to 60 mg/d), or cognitive behavioral therapy (CBT) (sixteen 50-minute sessions). The researchers then examined the change in participants’ scores on the 17-item Hamilton Depression Rating Scale (HAM-D), which was administered by raters who were blinded to treatment.
The average baseline HAM-D score was 19.8 (standard deviation [SD] 3.8). The average estimated overall decreases in HAM-D score were not significantly different between treatments (CBT: 10.2, escitalopram: 11.1, duloxetine: 11.2). Last observed remission rates also did not significantly differ between treatments (CBT: 41.9%, escitalopram: 46.7%, duloxetine: 54.7%).
“Patients matched to their preferred treatment were more likely to complete the trial but not more likely to achieve remission,” the researchers wrote.
“However, retention itself is an important outcome of relevance, particularly for patients with chronic forms of depression. We found a clinically meaningful number needed to treat for increasing completion (6.94 for matched compared with mismatched patients). Thus, until better predictors of remission probability are identified (as reported in our companion study to the present article) there may be value in using patient preferences to select initial treatments, particularly for those with moderate or strong preferences,” they concluded.2
Additional implications of this research include the fact that because more than half of the study’s population consisted of ethnic minorities, these treatment guidelines can be confidently extended to those populations.
The researchers also found that the neuroimaging data from their companion study has predictive value. Resting-state functional connectivity as determined by functional magnetic resonance imaging predicted remission and nonresponse rates with approximately 80% accuracy.2
- Dosages of duloxetine >60 mg/d are often used in clinical practice, suggesting that the full efficacy of this treatment may not have been detected
- Patients with mild depressive symptoms, concomitant substance use disorders, or very strong treatment preferences that made them unwilling to be randomly assigned to treatment were excluded from the study, which may limit generalizability
- Many participants expressed no preference; therefore, the study’s examination of preference on outcome was underpowered
- Without a “patient’s choice” treatment arm, the researchers could not assess whether this would have led to improved outcomes compared with randomization
- Assessing patients before treatment about their ambivalence in continuing treatment may have affected the analysis of treatment discontinuation
1. Dunlop BW, Kelley ME, Aponte-Rivera V, et al. Effects of patient preferences on outcomes in the Predictors of Remission in Depression to Individual and Combined Treatments (PReDICT) study [published online March 24, 2017]. Am J Psychiatry. doi:10.1176/appi.ajp.2016.16050517
2. Dunlop BW, Rajendra JK, Craighead WE, et al. Functional connectivity of the subcallosal cingulate cortex and differential outcomes to treatment with cognitive-behavioral therapy or antidepressant medication for major depressive disorder [published online March 24, 2017]. Am J Psychiatry. doi:10.1176/appi.ajp.2016.16050518