Reading Too Much Into a Depression Study
When something sounds too simplistic to be true, it probably is.
So when this headline crossed my desk earlier this week, Clinically depressed people may have damaged brain circuits, it definitely caught my attention. I was expecting to read about a study that examined damaged brains, or, at the very least, damaged brain circuits.
Instead, what I read about was a study that looked at fMRIs of people who were depressed and not depressed, a study design replicated so often that it’s no longer interesting. It found that brain activity in a certain area of the brain was different during a particular activity in people who were depressed than those who weren’t (whopee!). But here’s the key passage:
In the depressed individuals, high levels of activity in the amygdala persisted in spite of the intense activity in the regulatory regions, and even increased in response to it, suggesting that their conscious effort to recalibrate their emotions was thwarted by dysfunctional brain circuits.
The researchers speculated that signals from the prefrontal cortical area of the brain are not getting through to the amygdala in the depressed individuals for reasons still unknown.
The findings suggest that cognitive behavioral therapies that hold that an individual can change the way they feel about a situation by changing the way they think about it may be counterproductive for some people.
Really now? Given how little we understand about how the brain works and how the brain even causes us to have a certain emotional reaction (or not have one), I think this is a pretty big logical leap from a bunch of pretty pictures. A statement like this leaves us with so many additional questions and alternative hypotheses:
1. Is this a temporary effect of the artificial experimental conditions (since it was an artificial experimental situation, not a real life situation involving real social interactions) or a long-term emotional state?
2. Could depressed individuals simply be too tired, too unfocused, and too disinterested in regulating their emotional responses to this experimental condition, since it matters little to them? After all, depressed individuals aren’t known to have the same kinds of energy levels or focus as non-depressed individuals.
3. Isn’t any comment about psychotherapy completely inane and unethical given that the study done (a) didn’t examine any aspect of psychotherapy (b) patients in psychotherapy or (c) patients in psychotherapy who were being studied? It’s like saying, “Well, we studied 21 of these orange trees over here, and their growth seems to have a negative environmental impact on global warming.”
Now, researchers are convinced that fMRIs give us valuable insights into the very nature of the brain and how it works. But all it really shows are the changes in blood oxygenation and flow that occur in response to neural activity.
I’m sure there is value to this kind of research (although I’m not aware of any research in this particular area that’s resulted in a new treatment or more effective treatment technique to date in mental health). But there is no value in the way some news organizations, perhaps with the right quotes from some of the researchers, spin this study’s results:
“Our results suggest that there is a subgroup of patients with depression for whom traditional cognitive therapy may be contraindicated,” Davidson says. “Other therapeutic interventions may benefit this subgroup more than cognitive therapy, though this remains to be studied in future research.”
No, your results do not suggest anything about psychotherapy because (a) your N is tiny (21) and (b) you didn’t study psychotherapy! This statement just flies in the face of all previous psychotherapy and depression research, and ignores the research backing the combined use of psychotherapy and antidepressant medications as being the most effective. Come back and do a study that actually looks at real patients in real psychotherapy and measure their brains in the real world, in real-world situations, then you can talk about psychotherapy’s effectiveness. Otherwise, keep your comments to what your small dataset actually measured and show.
I don’t mean to be cynical, but perhaps Davidson’s quote about psychotherapy is partially driven by one of the funding sources for the study, Wyeth-Ayerst Pharmaceuticals.
Grohol, J. (2007). Reading Too Much Into a Depression Study. Psych Central. Retrieved on April 27, 2015, from http://psychcentral.com/blog/archives/2007/08/16/reading-too-much-into-a-depression-study/