Both people who have never been depressed and those who are wondering if they could be depressed may see depression as an illness that's "all in the head" — with symptoms like feeling sad, crying, irritable, guilty, worthless, pessimistic, hopeless, or suicidal. Nothing could be further from the truth, as several of the actual diagnostic criteria for major depressive disorder are indeed physical symptoms.
"All in the head" also gets complex really fast for a different reason, as it can, of course, refer to the physical brain as well as the mind, and a whole lot of things are going on in the brains of depressed people, in brain regions like the amygdala, hippocampus, prefrontal cortex, and brain stem, as well as with brain chemistry.
The physical symptoms of depression
Research is still uncovering ways in which depression can manifest physically, but for now, we know that many depressed people suffer from:
- Joint pain
- Limb pain
- Back pain
- Gastrointestinal problems (including stomach pain and constipation)
- Sleep disturbances — either being unable to go to sleep or stay asleep (insomnia) or exessive sleeping
- Fatigue or consistent low energy levels (even if you sleep well)
- A physical slowing down, wherein the person moves more slowly (called psychomotor retardation)
- Being physically restless, fidgety, and agitated (called psychomotor agitation)
- Loss of libido
- Appetite changes, either feeling the urge to eat more or not feeling like eating, and associated weight changes
- Migraine headaches
- In women, changes within the menstrual cycle
Fatigue, appetite and weight changes, a physical slowing down or speeding up, low energy levels, and sleep disturbances are all so well-recognized as possible symptoms of depression that they are included in the diagnostic criteria for major depressive disorder in the current edition of the Diagnostic and Statistical Manual of Mental Disorders, the DSM-5, just like they were in previous incarnations of the document. The other symptoms, while discussed less often, are no less important.
Consider, for instance, that:
- The neurotransmitters serotonin and norepinephrine in part determine how we feel pain, and as you'll have heard, but an imbalance of these "brain chemicals" also plays a large role in depression. Antidepressants, in fact, seek to return the functioning of these neurotransmitters to a more healthy state, thereby relieving symptoms.
- Research has found that depressed people have a lower pain tolerance than people who aren't depressed.
- It's no coincidence that antidepressants are also prescribed to people with chronic pain who aren't clinically depressed.
Depression can cause pain, but pain can also strongly contribute to depression. One study that looked at rates of depression in chronic pain patients, studying over a thousand participants, revealed that an alarming 60 percent of patients met the diagnostic criteria for depression, with a third being severely depressed. When you consider the impact chronic pain can have on a person's quality of life, that is no surprise at all.
Why it is important to recognize the physical symptoms of depression
Many depressed people are reluctant to seek medical attention for the mental symptoms of depression — because they don't recognize they are depressed, because they believe that nothing can help them feel better, or because they are embarrassed. Research shows, on the other hand, that depressed patients are far more willing to go to the doctor for physical symptoms they may not even realize are related to depression.
One study found that the more physical symptoms you suffer from, the more likely you are to have a mood disorder, an umbrella heading that includes depression. Only two percent of people who had either no physical symptoms or just one were later diagnosed with a mood disorder, for instance, while over a half of those who had nine or more physical complaints had such a disorder.
When is it time to see a doctor?
Anyone suffering from persistent, unexplained, physical complaints is right to see a doctor — depression is just one of the possible causes of the symptoms we've mentioned, and you should still check in with your healthcare provider if your mood is absolutely peachy. If you recognize several of the diagnostic criteria, a mixture of physical and mental symptoms, you may be depressed and can tell your doctor that you suspect depression:
- Depressed mood — feeling low, sad, empty, irritable, or numb
- A loss of interest in activities you previously enjoyed or found meaningful
- Weight loss or weight gain, associated with appetite changes
- Insomnia or oversleeping
- Psychomotor agitation or retardation
- Fatigue or low energy
- Persistent feelings of worthlessness or inappropriate guilt
- Trouble concentrating and making decisions
- Thinking about death or suicide, or planning to commit suicide
You need at least five of these symptoms, for at least two weeks (on most days or most of the day) to be diagnosed with major depressive disorder, but if you have fewer symptoms, still see your doctor — if you recently suffered a loss or stressful event and aren't coping well, you may have adjustment disorder with depressed mood ("situational depression") instead, and still benefit from treatment.