Neuroimaging may help in determining the best first-line treatment for patients with major depressive disorder (MDD), a new study suggests.
Results showed that pretreatment brain activity in the right anterior insula on positron emission tomography (PET) predicted whether depressed patients would best achieve remission with an antidepressant or cognitive-behavioral therapy (CBT).
"Our goal is to develop reliable biomarkers that match an individual patient to the treatment option most likely to be successful, while also avoiding those that will be ineffective," Helen Mayberg, MD, of Emory University in Atlanta, Georgia, who worked on the study, said in a statement.
The study, funded by the National Institutes of Health, was published online June 12 in JAMA Psychiatry.
"For the treatment of mental disorders, brain imaging remains primarily a research tool, yet these results demonstrate how it may be on the cusp of aiding in clinical decision-making," Thomas R. Insel, MD, director of the National Institute of Mental Health, who was not involved in the study, said in a statement.
Beyond Trial and Error
Currently, determining whether a particular patient with MDD will respond best to psychotherapy or medication is based largely on trial and error, the authors note in their article. It is estimated that fewer than 40% of patients achieve remission following initial treatment.
In this report, Dr. Mayberg and colleagues suggest that they have identified a potential biomarker to help predict which type of treatment (medication or psychotherapy) will work best.
They used fluorine-18 fluorodeoxyglucose (FDG) PET to measure brain glucose metabolism at rest in a group of patients with MDD prior to random assignment to escitalopram (10 - 20 mg/day) or 16 sessions of CBT for 12 weeks.
The primary analysis was based on 38 patients with clear outcomes and usable PET scans: 12 remitters to CBT, 11 remitters to escitalopram, 9 nonresponders to CBT, and 6 nonresponders to escitalopram.
"We analyzed the baseline PET scans as a function of outcome to identify whether or not there was a discriminator between CBT remitters, drug remitters, and the nonresponders in both groups," Dr. Mayberg explained in a JAMA Psychiatry podcast.
They identified 6 limbic and cortical regions that could differentiate these 4 groups; they report that the right anterior insula showed the most robust discriminant properties across groups (effect size = 1.43).
In particular, insula hypometabolism was associated with remission to CBT and poor response to escitalopram, whereas insula hypermetabolism was associated with remission to escitalopram and poor response to CBT.
"These data suggest that insula metabolism alone (relative to each person's whole-brain mean metabolism) may serve as a pretreatment biomarker to guide initial treatment selection (medication vs CBT) for a patient presenting with a major depressive episode," the researchers say.
"If these findings are confirmed in follow-up replication studies, scans of anterior insula activity could become clinically useful to guide more effective initial treatment decisions, offering a first step towards personalized medicine measures in the treatment of major depression," Dr. Mayberg commented.
The role of the anterior insula in major depression is well established. The anterior insula is known to be important in regulating emotional states, self-awareness, decision-making, and other thinking tasks. Changes in insula activity have been observed in studies of various depression treatments, including medication, mindfulness training, vagal nerve stimulation, and deep brain stimulation.
Dr. Mayberg has received consulting and intellectual property licensing fees from St. Jude Medical. A complete list of author disclosures is given in the original article.
JAMA Psychiatry. Published online June 12, 2013. Full article
