Depression: Just Take Advil and Aleve?
Could depression have something to do with inflammation? The idea sounds odd at first, but there's a real argument behind it. When your body fights off the flu, or manages a chronic illness like diabetes, asthma, cancer, or heart disease, the immune system kicks in with an inflammatory response. Part of that response involves cytokines, signaling agents that come in two flavors: pro-inflammatory ones that ramp inflammation up, and anti-inflammatory ones that calm it back down. Inflammation is also what shows up when you have a headache or smash your thumb with a hammer. That throbbing swelling around the injury? Inflammation at work.
The connection to mood comes from what researchers have measured in people living with depression. In several studies, patients with clinical depression showed higher levels of pro-inflammatory cytokines and lower levels of the anti-inflammatory kind. Put plainly, their bodies were sitting in an inflamed state while they were depressed.
There's a loose resemblance to how a cold moves through you. At the start it's mild: a runny nose, a throat that feels scratchy. Then maybe a fever creeps in, low-grade or higher. A few days later the worst of it arrives, with coughing, sneezing, wheezing. Then the virus loses steam, the symptoms ease off, and you're back to normal. Depression tends to move in stages too. You might first notice yourself feeling a little down, a little drained. The feeling deepens. If it gets severe enough, some people end up needing hospital care. Over time the symptoms recede and energy returns. Because the two run through such similar arcs, inflammation may well be a shared thread.
Think again about the hammer. Damaged tissue goes red and swells. Brain tissue follows the same rules. When it takes a hit from trauma, infection, or a chemical disturbance set off by an intense emotional event, the brain can release pro-inflammatory cytokines of its own. The result can look like an inflammation of mood: more anger, more anxiety, more of that raw emotional ache. When the trigger is serious and nobody treats it, that emotional inflammation can tip into a full depressive episode.
What's stranger is that inflammation nowhere near the brain seems to matter too. Researchers at the American College of Neuropsychopharmacology found that rats carrying higher levels of interleukin-6, a pro-inflammatory chemical, showed depressive behavior. The chemical turned up in the peripheral immune system, in places like the spleen and lymph nodes. That points to a possibility worth chewing on: immune trouble outside the central nervous system might signal who is prone to depression. If that holds, doctors may eventually address some cases of clinical depression by treating inflammation in the body rather than targeting the brain directly.
Angelos Halaris, MD, PhD, a psychiatrist at Loyola University Medical Center, is already running with this. He has given the approach a name, Psychocardiology, and he uses it to treat cardiovascular disease and depression together. His work found that same interleukin-6 running high in people with heart disease. A few figures round out the picture: somewhere between 40 and 60 percent of heart disease patients also deal with depression, while 30 to 50 percent of people with clinical depression are at risk for heart disease. Inflammation can drive chronic depression, and chronic depression can drive inflammation right back. For a clinician, that means a patient's physical symptoms and mental symptoms both belong on the chart before any treatment plan gets written.
So, Advil and Aleve for depression? Anti-inflammatory drugs have shown some early promise against depressive symptoms. When researchers paired non-steroidal anti-inflammatories like these with standard SSRI antidepressants (selective serotonin reuptake inhibitors), they recorded a statistically significant drop in depressive symptoms compared with the SSRI alone. None of this cracks the problem open completely, but it nudges mental health professionals toward sharper ideas about what causes depression and how to treat it. And it reinforces something simple: depression and other mental-health conditions sit closer to the rest of the body's diseases than we tend to assume.
Melissa Lavery, M.S.