Today, figuring out who will benefit from which antidepressant medication is hit or miss—physicians prescribe a medication to treat major depression for two to three months, and then gauge the results. This trial and error is frustrating and expensive; typically only about 40% get well after this first treatment or see an improvement in symptoms. The other 60% must try a different drug or some other approach. In a new NIH funded study, researchers showed how brain scans could predict which individuals would benefit from a medication and which might respond better to psychotherapy .
The researchers measured resting brain activity in 63 patients suffering from depression using a brain scanning technique called positron emission tomography (PET). PET measures how much glucose—brain fuel—various regions of the brain are consuming as a proxy to measure which areas are most active. After the scans, patients either received 12 weeks of an antidepressant medication or 12 weeks of cognitive behavior therapy (CBT).
The researchers found that activity levels in a brain region called the anterior insula—known to play a role in emotion, self-awareness, and decision-making—was associated with whether an individual would benefit from CBT vs. escitalopram, a common antidepressant that alters the level of certain chemical messengers in the brain.
In general, those patients with low activity in their anterior insula responded well to CBT, but not to medication. Those with hyperactivity in this region had better results with the medication, with depression going into remission. Conversely, CBT wasn’t as effective in this group.
Before scans like these can be used for patients, we need to repeat the studies and trials to make sure that the findings hold true. Discovering a reliable biomarker to guide clinical decisions could personalize the treatment of depression, which currently affects almost 7% of Americans . Developing better treatments is critical because depression can be a very serious illness. Depression increases risk of suicide and affects every facet of life: work, sleep, study, eating, and the enjoyment of activities an individual once found pleasurable.
Choosing the best treatment the first time around would reduce patient distress and decrease the enormous healthcare costs and economic burden caused by this disease. As we learn more about the brain through endeavors like the BRAIN Initiative, I expect we’ll discover “brain types” that may eventually help physicians personalize treatments—not just for depression, but for many illnesses that affect the brain.
 Toward a Neuroimaging Treatment Selection Biomarker for Major Depressive Disorder. McGrath CL, Kelley ME, Holtzheimer PE, Dunlop BW, Craighead WE, Franco AR, Craddock RC, Mayberg HS. JAMA Psychiatry. 2013 Jun 12:1-9
 Major Depressive Disorder Among Adults (NIH Factsheet)
NIH support: National Institute of Mental Health; National Institute of General Medical Sciences