Practically everyone has felt depressed at some point during their lives – after the loss of a loved one, after a heartbreak, or after disappointingly not achieving an important goal. For most people, the sadness, pessimism, and withdrawal they feel during those times are relatively transient. But for about 7% of people, the problems persist and become Major Depressive Disorder. There are several different “kinds” of depression, but here I focus on the most common, called Major Depressive Disorder. Here are 6 things you need to know about Major Depression.
1. Causes of Depression
Major Depressive Disorder is caused by a combination of the following factors:
- biological (e.g., genetics, medical conditions, hormonal balances)
- psychological (e.g., thought patterns, behavioral patterns)
- and social (e.g., stressors, trauma)
2. Symptoms of Depression
Two people who are both diagnosed with depression can have widely different symptoms. One might be sleeping too much, while another can’t sleep at all. Similarly, one might be overeating, while another is skipping meals. Some are restless and somewhat agitated, while others feel like they’re moving in slow motion, trudging through mud. Emotionally, people with depression tend to feel sad, down, or empty. Things they used to enjoy doing no longer seem fun, and they might isolate from their friends and family. They have difficulty concentrating and making decisions, feel guilty about things that logically aren’t their fault, and feel hopeless and helpless about their future. At the most extreme, they might think that life is no longer worth living and begin entertaining thoughts of suicide. If you are having suicidal thoughts, call 1800-273-TALK or go to your local emergency room.
3. How Depression "Works": Neurobiology
Despite all the research on Major Depression over the last few decades, we still have a relatively poor understanding of what’s causing it in the brain. We do know certain areas of the brain are smaller in people with depression, like the hippocampus (which helps us create long-term memories), dorsomedial prefrontal cortex (involved in planning, personality, understanding social information), orbitofrontal cortex (helps us make thought-out decisions and plays a role in emotional processing), and anterior cingulate cortex (which helps us manage and regulate our feelings). In addition, certain areas of the brain are less active in people with depression, like the subgenual cingulate (processes sadness) and ventral striatum (regulates decision-making and behavior related to rewards), and certain areas are more active in people with depression, like the amygdala (which regulates how afraid we feel). Image credit.
4. Treatment of Depression
Major Depressive Disorder is often treated with a combination of medication and psychotherapy. Regarding medication, selective serotonin reuptake inhibitors (SSRIs) and serotonin-norepinephrine reuptake inhibitors (SNRIs) increase the amount of serotonin and norepinephrine in the brain, which tends to relieve depressive symptoms. It works like this: a neuron in the brain pumps out serotonin (the green stuff in the image below) into a gap between itself and the next neuron. Some of the serotonin is sucked up by the next neuron (#1 in image below). Usually, the extra serotonin is sucked back up by the first neuron and recycled for the next go-around (#2 and #3). But the SSRI or SNRI keeps more of the extra serotonin in that gap so it can be sucked up by the next neuron, meaning more serotonin gets to that next neuron than usual. Image credit.
5. Psychotherapy for Depression
Psychotherapy can also be helpful, and there are several treatments with proven effectiveness for treating depression, including cognitive-behavioral therapy and interpersonal psychotherapy. Lifestyle changes are also important, such as changing diet and exercise habits, prioritizing regular sleep, and engaging in pleasurable activities. Your psychologist can help you set goals around these areas and implement these lifestyle changes.
6. Physical Effects of Depression
Physical Effects: Depression has a major impact on your body. Here is an infographic from healthline that demonstrates some of the effects. The corresponding article has more information.
For more information about Major Depressive Disorder, check out the World Health Organization, National Institute of Mental Health, or National Alliance on Mental Illness.
Hayden C. Finch, PhD,
is a practicing psychologist
in Des Moines, Iowa.