(Photo credit: Fox valley Institute)
That depression affects a massive and growing number of Americans is not news. Neither is the fact that some of the drugs used to treat it are mournfully ineffective, even in their newest iterations, with remission rates of just about 40%. In fact, some studies have suggested that they can be little, if any, more effective than placebo (though other studies have contradicted this). Psychotherapeutic methods like cognitive behavior therapy (CBT) can help, but also leave something to be desired in long-term efficacy. This is where a new study comes in, suggesting that brain imaging could help determine whether one might have the best shot at remission with meds or talk therapy.
In the study, the researchers from Emory used PET scans to look at the brain activity of 63 people with depression, ranging from 18 to 60 years old. PET scans measure the use of glucose in the brain, a good marker for the activity level of the brain cells in a given area. The participants were then randomly assigned to receive either escitalopram oxalate (Lexapro®) or CBT for 12 weeks.
As it turned out, some of the participants had more or less activity in certain areas of the brain which have been linked to depression, but the one that stood out was an area called the insula, which helps turn our visceral responses into subjective perception. It's also linked to some of the thought patterns common in depression, like emotional self-awareness, sensing your internal physiological state, decision-making, and cognitive control.
And it turned out that the activity level in one's insula was correlated with how they responded to the different treatments. People who had less activity in the anterior part of the insula had better odds of achieving remission with CBT, but lower chances of with medication. The situation was reversed for people who had higher baseline activity in the insula – they had a better shot at finding remission with the medication, and less with CBT. Keep in mind that these results were based on only 38 people – those who had clear-cut results with either of the treatments (some people had no improvement or too little to be considered significant).
The study makes the worthwhile point that some brains just seem to be set up differently, which affects how they respond to treatment – this is particularly relevant since, as the authors point out, when a medication doesn’t work for a patient, he or she is often put on another one, rather than being switched to psychotherapy.
The next step, of course, will be to assign people to treatment based on their brain scans at the outset. If remission rates are much higher than you’d expect with a random assignment, then the researchers may be on to something.
One drawback is the cost of the scans, which can run upwards of $2,000, not to mention the exposure to radiation. That said, the cost of depression may be a lot higher: Emotionally and financially, in ineffective treatments, and lost work and productivity over the years.
Brain imaging, which gained so much popularity a couple of decades ago, has had mixed success. Many hoped that imaging would bring about a profound understanding of brain function – and fast. But this has proven to be somewhat less of a reality than we might have hoped, though it’s led to some interesting developments, and certainly to some pretty pictures. That said, other recent studies have suggested using scans to diagnose other mental illnesses, including bipolar disorder. And the director of the National Institute of Mental Health has recently denounced the use of the DSM, the “bible” created by the American Psychiatric Association for diagnosing psychiatric disorders, favoring instead the use of brain scans, genetic tests, and psychological testing. (For a nice overview of that ongoing discussion, see this New Yorker piece.)
All that said, the authors of the current study are hopeful, the caveat being that there needs to be some follow-up done fairly quickly, and eventually with other medications and forms of psychotherapy. "If these findings are confirmed in follow-up replication studies,” said Emory’s Helen Mayberg in a statement, “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." Time will tell if this proves to be the case.
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