According to the National Institutes of Health, in 2021, 8.3% of the U.S. adult population had experienced an episode of major depression over the previous year. This translates to 21 million adults with a major depressive episode. Clinicians have long relied on the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) as a resource to diagnose patients with depression. However, diagnosing depression can present challenges, as it often depends on how clearly patients can communicate their symptoms to their provider and how well a provider can assess a patient based on their self-reporting.
To improve diagnosis and treatment, researchers have been using brain scans to identify changes in the brain that contribute to depression. For example, positron emission tomography (PET) scans and magnetic resonance imaging (MRI) scans may help clinicians detect specific characteristics in the brain structure or brain activity that relate to depression.
The hope is that brain scans will lead to earlier diagnoses and more effective treatments for depression.
Considering getting a brain scan to detect depression?
One of the types of brain scans that a clinician might use to detect depression is a PET scan. PET is an acronym for positron emission tomography, which refers to an imaging process that looks at organs and tissues. Doctors sometimes use PET images in conjunction with CT or MRI scans to get a clearer picture of the areas they’re studying for people experiencing depression.
Areas of unusual activity that show up on PET scans have sometimes helped doctors detect brain disorders, some types of cancer, and heart disease. PET brain scans sometimes show areas of disease before they show up on other types of brain scans.
While PET scans may provide useful information to doctors, they can present some risks. The drug tracer that is typically used contains a small amount of radiation. The risk of negative effects may be relatively low; however, the radiation can cause an extreme allergic reaction in rare incidents. Also, radiation, even in a small amount, can be harmful to people who are pregnant or nursing.
The results of PET scans typically go to radiologists, who interpret the brain scans and report the results to the treating physician. Doctors may compare the results from PET scans to those of other tests like CT or MRI scans. This process may provide the clearest picture of a person’s condition.
Using an MRI to study the blood-brain barrier
Advances in medicine have produced new types of MRI scans that reveal features of depression in the brain. One type of brain scan shows differences in the blood-brain barrier (BBB). This research was furthered by Kenneth T. Wengler, Ph.D., a researcher at Columbia University who studied the links between major depressive disorder and the blood-brain barrier (BBB).
The BBB has a unique structure that allows the brain’s blood vessels to control the movement of molecules and cells between them and other bodily tissues. The function of the BBB is to shield the brain from harmful toxins and pathogens that may be running through the bloodstream.
Working in collaboration with researchers from the Renaissance School of Medicine at Stony Brook University, Dr. Wengler developed a new type of MRI named IDEALS, which is an acronym for intrinsic diffusivity encoding off arterial labeled spins. This type of MRI allows researchers to track how water moves across the BBB. Wengler and his team used IDEALS in a study of 14 individuals living with major depressive disorder (MDD) and 14 control participants without MDD.
The results of the study showed that the participants with major depressive disorder had a reduced capacity for water permeability in their BBBs. Essentially, for people with depressive disorder, less water moves from their blood vessels into brain tissue. The water moved more freely in the participants who were part of the control group.
Dr. Wengler and his team also reported that the difference in the permeability of the water was notable in the amygdala and hippocampus regions of the brain. Previous research studies in brain imaging have suggested that these two brain regions may be essential in understanding the workings of the brain as it relates to major depressive disorder. Dr. Wengler and his team were able to observe changes in the BBB in gray matter areas of the brain that they suspected would be altered in people who have major depressive disorder.
Getty/Vadym Pastukh
Considering getting a brain scan to detect depression?
Another MRI brain scan may reveal differences in the complex network of the brain’s connections, as evidenced by a second study using MRI imaging conducted by Guoshi Li, Ph.D. and fellow researchers at the Image Display, Enhancement, and Analysis Group at the University of North Carolina School of Medicine.
Together, they explored disruptions to something that scientists call the connectome.
Dr. Li and his team used a new tool called a multiscale neural model inversion framework in conjunction with a functional MRI (fMRI), whereby they conducted a study that included 66 adults living with major depressive disorder (MDD) and 66 control participants without MDD.
In this study, Dr. Li and his colleagues were able to look at the activity in microscopic circuits as they relate to large-scale brain activity. Research suggests that healthy brains work most productively when they have a balance between excitation and inhibition, so Dr. Li and his team assessed the functions of excitation and inhibition among the circuits of the brain cells.
The results of the functional MRI scans showed that people with major depressive disorder had different patterns of excitation and inhibition in the dorsal lateral prefrontal cortex, as compared with the patterns of the control group. The dorsal lateral prefrontal cortex is thought to help manage the amygdala in the brain. Scientists believe that the symptoms of depression can surface when the brain doesn’t inhibit the amygdala appropriately.
Dr. Li’s study showed that excitation and inhibition were reduced in patients with major depressive disorder, which may have affected their executive function and emotional control. Proper executive function tends to help us plan, focus, remember things, and multitask.
This study also suggests that the control functions in individuals with major depressive disorder may be impaired, which could lead to greater responses from the amygdala. The result of this is likely an increase in a person’s anxiety or other negative moods.
Dr. Li’s study also showed that the thalamus, which is another part of the brain that’s typically involved in emotional control, tended to show higher recurrent excitation in people living with major depressive disorder.
Online counseling with BetterHelp
Brain scans can be a powerful tool for researchers to study brain disorders, which could pave the way for more effective diagnosis and treatment of major depressive disorder. In the meantime, if you’re experiencing symptoms of depression, whether mild or severe, it may be helpful to seek support from a physician or mental health professional. If you don’t feel well enough for traditional in-office therapy, you might consider online therapy, which has been shown to be effective for adult depression. One study found that a multimodal digital psychotherapy platform significantly reduced depression symptom severity.
Through an online counseling platform, you can connect with licensed therapists from the comfort of your home via phone, live chat, or videoconferencing. With some platforms, you can also write to your therapist at any time through in-app messaging, and they’ll respond as soon as they can.
Takeaway
Brain scans may allow researchers to discover more about the mechanisms of depression in the brain. In some cases, professionals may be able to make more accurate diagnoses with brain scans and create more personalized treatment plans for individuals experiencing mental illness. If you think you may be experiencing depression, it may help to speak with a licensed therapist. With BetterHelp, you can be matched with a licensed online therapist who has experience working with people who live with depression. Take the first step toward learning more about depression and reach out to BetterHelp today.
Frequently asked questions
Read more below for answers to questions commonly asked about this topic.
Can a brain scan show depression?
There is no “depression section” of the brain that lights up on a scan to definitively determine that someone has the disorder. However, some details from studies that compare brain activity of people with major depressive disorder and people without the condition indicate that depression may have a physical brain component.
Can a brain MRI detect depression?
MRI scans have been used to study and treat medical situations involving the blood-brain barrier, which scientists believe may function differently in people with depression. Under normal and healthy circumstances, the blood-brain barrier helps to prevent toxins that may be circulating within the bloodstream from entering the brain (a unique feature, as no other organ has this level of safeguarding services). Preliminary research findings indicate that people with depression may have differences in their brain structures that could have been influenced by changes in blood-brain barrier functioning, which may show up on a brain MRI. However, a brain MRI cannot be used to make a depression diagnosis.
Do you need a brain scan for depression?
Brain scans cannot diagnose or treat depression, so it would be wrong to suggest that anyone with suspected or diagnosed depression needs to receive a brain scan.
How do doctors scan for depression?
Doctors typically scan for depression using a questionnaire that details depression symptoms, including symptom frequency and duration. Doctors may also incorporate other information into a depression diagnosis, such as the mental health status of family members, as mental health conditions like depression can run in families. Different screening procedures will likely be used to diagnose depression in children.
Can a brain scan show anxiety?
Similar to depression, brain scans cannot provide enough information for a definitive anxiety disorder diagnosis. However, research does indicate that anxiety has an impact on the brain, with the brain’s “fear centers” of the amygdala and insula and anterior cingulate cortex showing higher levels of activity when patients are experiencing anxious emotions. Increased activity in these areas may indicate a greater likelihood of an anxiety disorder.
Can a brain scan detect mental illness?
A brain scan on its own cannot detect mental illness. However, brain scans in conjunction with physician and therapist evaluations can lead to a mental health diagnosis.
Can a brain scan show anxiety and depression?
Anxiety and depression can have impacts on the brain which may be visible during a brain scan; however, a brain scan will not provide enough information to form an anxiety or depression diagnosis.
What happens in the brain during depression?
More information is needed to fully understand the impact that depression can have on the brain, but current research suggests that depression is associated with lower levels of neuroplasticity. Neuroplasticity refers to the ability of brain cells, or neurons, to adapt to changing circumstances and stressors. Higher levels of neuroplasticity are typically linked to better brain functioning, so decreases in neuroplasticity that are linked to depression can have a negative impact on the brain.
How much is a depression brain scan?
Given the paucity of research on the effectiveness of brain scans to diagnose depression, most insurance plans will likely not cover the cost of such a scan. This situation means that even if your medical providers accept Medicare, Medicaid, or personal insurance, you will probably still be billed out of pocket. It is unlikely that any medical provider would recommend such a procedure since brain scans cannot diagnose depression.
Is depression a brain abnormality?
Depression can show up in different ways for different people, so not everybody diagnosed with depression will demonstrate the same impacts on their body or brain. However, research indicates that people with depression can demonstrate lower levels of activity in certain areas of the brain, such as the dorsolateral prefrontal cortex (responsible for problem-solving) and the anterior cingulate cortex (responsible for emotion control).
The information on this page is not intended to be a substitution for diagnosis, treatment, or informed professional advice. You should not take any action or avoid taking any action without consulting with a qualified mental health professional. For more information, please read our terms of use.
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