fMRI and evidence-based psychiatry
Why have psychiatrists delayed adoption of fMRI technology?
For anyone who has been distressed by psychiatry’s failure to incorporate evidence-based medicine the era of functional MRI has arrived!
Anyone who has ever bought a hot dog near a subway station can admit that we need psychiatrists, and they do a tough, societally-necessary job. But is there any way to make clinical decision-making more accurate?
A 2017 paper published in Nature used 1,188 whole-brain scans to substantiate that subjective low mood is associated with biological changes in the brain. Pathology primarily localizes to connections between conscious control of emotion in the cortex and the experience of mood in the limbic system.
This marks a sea-change in the ability of psychiatry to join the rest of medicine in seeking evidence for its conclusions.
Why don’t we have evidence-based psychiatry?
This is a great question. In fact, it’s a question I wish the public asked doctors more frequently… perhaps daily.
Currently, the best diagnostic criteria we have for psychiatric disorders is the Diagnostic and Statistical Manual of Mental Disorders (DSM-5). As a “consensus of the experts” this is the lowest level of medical evidence.
The DSM is not only scientifically questionable. Because the DSM is generally created by the consensus of one gender/socioeconomic class also been roundly criticized for pathologizing and thus further stigmatizing already stigmatized socioeconomic groups.
As an example:
- Homosexuality was only removed as pathology in 1973 in response to lobbying by human rights groups and queer psychiatrists themselves!
- Bias exists when translating the classification schema for alcoholism to the Hispanic language and culture.
- The DSM fails to account for healthy experiences of altered states in other cultures healers such as anthropologists document among shamanic and indigenous medicine men.
- Female “hysteria” used to be treated with burning for sorcery. Over the years its nomenclature and treatment evolved, although Freud still considered it a purely female disease. Not to worry, the condition was finally deleted from the DSM… in 1980.
- There is emerging evidence that antipsychotics are ineffective in treating populations that experience auditory and visual hallucinations.
The good news is we don’t have to keep arguing about our opinions of what is sane. Good science, properly applied can dispel a lot of the debate.
Functional MRI in depression
Recent fMRI evidence would both vindicate, and expand clinical psychiatric classification.
In the Nature study, Drysdale et al. found that up to four distinct patterns of abnormal connectivity were included under the DSM-5 classification of “major depressive disorder”. This means that the clinical classification system is probably a good catch-all, but not nearly subtle enough to match the biology of depression.
Additionally, some people who were classified as only having “generalized anxiety disorder” also matched the subset of depression brain scans that had biomarkers associated with anxiety. This means that while the clinical picture of depression and anxiety might overlap, the biomarkers might be more accurate.
Perhaps the most important part of the study, is that the biomarkers predicted response to treatment. Some subtypes were more responsive to medication, some were more responsive to nonmedical therapies.
Functional MRI and evidence-based psychiatry conclusion
Perhaps now we can crack the black box of the brain to devise better psychiatric therapies. Many of the studies on antidepressant medication for mental health have been biased by pharmaceutical influence on study design and reporting leading to an overestimation of efficacy. And there is a significant lack of studies on nonpharmacologic methods to prevent mental illness.
I am hopeful that if we can base classifications of mental illness on true biological changes, we can design better drug trials, stop pathologizing people who are societally disenfranchised, and perhaps even find better treatments.
FMRI might not only be a measurement, but it also holds promise as a therapy. Another recently published study successfully used fMRI neurofeedback as a treatment for low mood. Technology has always been a double-edged sword. Maybe instead of making us depressed, we can use it to teach ourselves to be happy!
Originally published at https://www.todreamalife.com on July 29, 2022.