Feeling nervous about surgery is normal and expected. But post-operative depression, a common and serious condition, is hardly acknowledged. How come? In the US alone, 60,000 people undergo general anesthesia for surgery every day. Recently my dad was one of them. The surgery went well and post-op healing from the incision and medical procedure itself went swimmingly. But something was wrong. What the doctors failed to tell him, and generally fail to disclose, is that general anesthesia is an assault on the brain. Far better than whiskey, modern anesthesia’s ability to knock us out is not without risk of side effects.
One common, though all-too-little discussed risk? Post-operative depression.
Post-operative depression. Up to 65% of people undergoing certain types of surgeries experience depression. It can be short-lived or can linger. Either way, it can have huge health consequences. Symptoms of post-operative depression vary from individual to individual, but common symptoms include changes in appetite and energy levels, shifts in mood such as apathy or irritability, fatigue, and feelings of hopelessness and despair. Post-operative depression is often overlooked or minimized by surgeons and hospital staff, overshadowed by the post-op focus on the surgery’s outcome – leaving patients like my dad unprepared.
But isn’t general anesthesia just a deep sleep? No. Neuroscience and sleep studies clearly demonstrate that general anesthesia is better thought of as a “reversible coma.” Imagine shutting down the power plant that runs your city – everything goes out from your lights to your hot water heater to you refrigerator. When it’s time to power back up, it happens incrementally, maybe block by block, and some things will inevitably need resetting, like the clock on your range. The same is true for our brains after general anesthesia, and this can cause mood alterations.
It’s all in your head. But that doesn’t mean it’s imaginary. General anesthesia has real physical impact on brain functioning (that’s why it works), but that is why it also carries the risk of depression following surgery. In addition, pain has been shown to cause altered synaptic connectivity at the prefrontal cortex and hippocampus, as well as altered dopamine signaling from the ventral tegmental area. These changes trigger symptoms of depression and may be a link between post-operative pain and depression. And there is the stress of surgery itself, which induces inflammatory responses, and genes related to inflammatory cytokines have been implicated in the aetiology of depression.
Who is most at risk? While difficult to predict, we know smoking, high levels of anxiety, high levels of cholesterol, heart disease, and a history of depression may increase risk. Certain kinds of surgeries are associated with greater risk of post-operative depression – with as many as 50% of coronary artery bypass graft patients showing signs of depression in the 6 months after surgery. But even if none of these describes you or your situation, you may be someone who is especially sensitive to this side effect of general anesthesia.
What’s the big deal? Well, to start, depression feels pretty awful. That would be bad enough, but post-operative depression, unrecognized and untreated, often leads to unnecessary additional medical appointments and tests, which in turn lead to a greater psychological and financial burden. In many (maybe most) cases, this experience of depression is fleeting. For some, however, it can become a serious and enduring condition associated with increased risk of post-operative infections and increased post-operative pain. If it lingers, it is important to get help.
Generally a gregarious, fun-loving soul who is always ready for a laugh, my dad was so down that he would not talk to any of his kids three days after surgery and wound up back in the Emergency Room in the middle of the night not understanding why he felt so bad. Many tests later, he returned home reassured by the ER staff that he was recovering from his surgery as expected. A few days later, his mood and energy were clearly on the mend as well.
Better prepared, we could have managed those post-op days without the additional emotional worries and medical procedures, all of which detract from healing. Consider this a heads up for the next time you or a loved one will undergo general anesthesia.