Depression in the Traumatized Brain

by Sandeep Vaishnavi MD, Ph.D., and Vani Rao, MD, PLLC

The word depression is thrown around often in daily conversation. We say we are depressed over a bad relationship, or a bad job situation, or even a bad day. When people use the word depression in this way, they don’t mean clinical depression. People use "depression" and "depressed" to describe feeling sad about something that would cause most people to feel sad. If we don’t get the promotion we think we deserve, or if we get into a fight with our spouse, or if our child gets into trouble in school, we may call it being depressed, but what we're really feeling is just sadness. Sadness is not pathological. Sadness is a normal human emotion.

Clinical depression, also known as major depression, on the other hand, is a medical diagnosis describing sustained, persistent low (depressed) mood in a person who cannot enjoy usual activities and who may have physical symptoms such as trouble with sleep and concentration.

Unfortunately, inaccurate use of this medical term has permeated popular culture, making it harder for people to understand what depression really is. Our use of the word in this way makes it seem as if depression is not really a medical problem, but rather a “normal” response to life’s setbacks. Yet clinical depression is a medical condition and not a normal response to events.

Further complicating the situation is that, even in a medical sense, depression is not a single concept. Depression comes in many forms and has many diagnoses: major depressive disorder, dysthymia, bipolar depression, depressive disorder not otherwise specified, adjustment disorder with depressed mood, and many others. Depression is thus a spectrum of disorders, all of which can affect people mildly or severely, ranging from minor effects on relationships and work to suicide.

What separates a diagnosis of clinical depression from normal sadness—what separates pathology from normality—is whether the symptoms significantly affect functioning. Clinical depression can affect work performance, social relationships, home life, or any combination of these. Furthermore, to warrant the diagnosis of clinical depression, functioning must be persistently affected for a minimum amount of time (two weeks for a diagnosis of major depression.) Clinical depression is not an afternoon spent pouting or “having the blues” over a troubling situation. Clinical depression, in fact, can be autonomous, that is, unrelated to any single troubling event. It may occur with no “good reason” and persist for weeks or months. Of course, those who have had a TBI, and their family members, may already know from their own experience what major depression is, but using the correct terminology for it affects how people perceive what depressed patients are struggling with.

With traumatic brain injury, depressive symptoms are rather common, but here we have to be even more careful with terminology, because these symptoms may not fit neatly into a category such as major depressive disorder. Depression in TBI may be more diffuse and hard to diagnose precisely. Many factors can cause clinical depression after TBI: having a history of major depression before the TBI (a well-known risk factor), the severity of the injury (more severe injury increasing the risk), alcohol or substance abuse, and the presence of psychosocial problems (for example, minimal emotional support, poor finances, unemployment) before and after TBI. How exactly TBI causes major depression is unclear. TBI can act as a stressor and cause depression in someone who is already vulnerable to depression, or it can cause dysfunction of neural circuits or neurochemicals and trigger depression. Most TBI researchers believe that it probably does both.

Unfortunately, persons with TBI or their family members may be told by well-meaning people that it is “understandable” that they are depressed: “Of course you’re depressed! Look what you just went through.” Even medical professionals may succumb to this fallacy. It is not unusual to hear nonpsychiatric physicians say such things to their TBI patients. But, as we have discussed, it is not normal for a person with TBI to be clinically depressed. Depression is common in TBI, but it is not necessary. Clinical depression is not a normal part of recovery from brain injury.

This is an important distinction. When friends, or family, or even medical personnel accept depression as normal after TBI, they are doing the patient a disservice. The subtle implication is that these symptoms do not deserve treatment; after all, if this is normal, why treat it? And what may be implied when depressive symptoms persist is that the patient should be “getting over it.” So the person with TBI can interpret this attitude to mean that he or she has a character flaw or some kind of personal weakness. This message, of course, can make the patient feel even worse, thus perpetuating a cycle of deepening depression.

TBI can result directly from the brain injury itself or indirectly from factors such as the loss of a job or an unsupportive family. Depression can make symptoms of the brain injury worse, cause recovery efforts to falter, and contribute to other medical problems. Depression can be a fatal illness. Suicide is not uncommon in people who are clinically depressed. We ignore it at our own and our loved one’s peril.

Adapted from The Traumatized Brain: A Family Guide to Understanding Mood, Memory, and Behavior after Brain Injury, by Vani Rao and Sandeep Vaishnavi, Johns Hopkins University Press, 2015, excerpt used with permission.