Depression
What is Depression?
Depression is a very common and very serious mental illness that negatively impacts the way you feel, decisions you make, how you think, and how you behave. Depression can cause a sense of sadness, exhaustion, and lack of interest in life or things you once enjoyed. It is among the most common disabling clinical diagnoses in the world. Living with depression can lead to an individual developing other emotional and physical issues. Depression can have severe impacts on quality of life.
How Common is Depression?
The American Psychiatric Association estimates that 1 out of every 15 adults will experience depression this year. The World Health Organization claims that 17.1% of all adults will experience depression at some point during their lifetime [1]. Globally, it is estimated that depression affects 340 million people, and is affecting 18 million people in the United States alone at any given moment. Depression can develop at any point in a person’s life, but a common age of onset is during teenage years and early 20’s. It tends to disproportionately impact women more than men.
What Causes Depression?
It is difficult to identify a specific cause of depression, but best summarized, depression is caused by poor regulation of specific pathways involved in mood and motivation within the brain. Several factors should be assessed at the onset of depression, ranging from genetic vulnerability, medication changes, brain trauma and other traumatic life events. Often people hear that the cause is due to “too little of this chemical and too much of that chemical” within their brain. This is an oversimplification and does disservice to the individual living with depression. Many intricately designed pathways transmitting a handful of neurotransmitters need to be working well and in harmony in order for us to not be depressed. There are many points throughout these various pathways where dysfunction can occur and create depression.
What are the Symptoms of Depression?
Depression is more than a feeling of sadness or grief. Grief may come in waves, while depression is a consistent sadness and oppressed mood. Depression also brings on a decrease in interest in activities you once enjoyed, changes in appetite, changes in sleep patterns or increased sleep disturbances, fatigue, slowing of movements and speech patterns, difficulty concentrating or maintaining focus on a task for a long period of time, a sense of self-loathing, a sense of worthlessness, ongoing feelings of guilt, and thoughts of death or suicide.
What Happens to the Brain with Depression?
A study from May 2020 assessed the complex and various abnormalities that can occur to cause depression. It compiled data from the published literature, looking specifically at neuroimaging studies on subjects with major depressive disorder (MDD). The study identified several key structural abnormalities, as well as functional abnormalities, of very diverse brain regions that are located in different areas of the brain but it singled out one specific region within the left hippocampus as demonstrating abnormality consistently across all studies.
Identification of consistent abnormality within the subgenual anterior cingulate cortex in this meta-analysis is a potentially important finding for depression research. The subgenual cingulate has been widely implicated in major depression as a regulator of mood (2-6), in the processing of emotional stimuli (7-9), and as a target for network-based treatments such as deep brain stimulation and a downstream target for transcranial magnetic stimulation (10, 11).
Studies performed using transcranial magnetic stimulation have demonstrated a clear asymmetry between left and right frontal cortices when compared to non-depressed subjects. The left frontal cortex of depressed patients was less excitable, or reduced in function, compared to the right, suggesting important asymmetries that should be taken into consideration when tailoring therapy for a depressed patient.
To summarize, neuroimaging studies have documented aberrant structure, function, and connectivity in brain regions that correspond to aspects of emotion and emotional regulation that become deficient in MDD. Specifically, investigators have reported structural anomalies in MDD in the amygdala and hippocampus, and functional abnormalities in the subgenual anterior cingulate cortex, dorsolateral prefrontal cortex, amygdala, and ventral striatum.
There is also a typical pattern of asymmetry of function in the hemispheres of the brain, usually meaning the left frontal cortex is firing less frequently and intensely than the right frontal cortex in patients suffering with MDD. There is growing recognition that depressed individuals are characterized by abnormalities in the anatomical and functional connections among these brain regions.
TMS Treatment
Depression is often treated through the use of medications, usually anti-depressants, and psychotherapy, oftentimes simultaneously. Transcranial Magnetic Stimulation (TMS) is a safe way to non-invasively stimulate or inhibit regions of the brain associated with depression like the left or right dorsolateral prefrontal cortex. This is often a very effective way to treat those with depressive symptoms resistant to typical forms of treatment like anti-depressants and psychotherapy.
Your Next Best Step
Living with depression is extraordinarily challenging, but there is hope for recovery and freedom from this condition. To see if TMS is right for you, contact our front desk and schedule a free consultation with Shauna Hahn, PMHNP.
And remember, it’s never too late to start getting better.
References:
2. https://pubmed.ncbi.nlm.nih.gov/9126739/
3. https://pubmed.ncbi.nlm.nih.gov/18704495/
4. https://pubmed.ncbi.nlm.nih.gov/21145043/
5. https://pubmed.ncbi.nlm.nih.gov/15110034/
6. https://pubmed.ncbi.nlm.nih.gov/10327898/
7. https://pubmed.ncbi.nlm.nih.gov/16237317/
8. https://pubmed.ncbi.nlm.nih.gov/27013105/
9. https://pubmed.ncbi.nlm.nih.gov/29867204/