Hockey, Football, MMA, Soccer Headers: the Cumulative Hit Problem

If you played a contact sport for any length of time, you probably stopped counting the hits a long time ago. The stinger that made your ears ring. The header you cleared without thinking. The tackle where the field went a little white for a second, and then you got up because that is what you did. Most of those moments never made it into a medical chart. You shook it off, you finished the game, and you moved on. What fewer people talk about is that those smaller collisions can add up quietly, and the bill sometimes does not arrive until years or decades later.

The hits you forgot may not have forgotten you

When people picture a head injury, they picture the dramatic one: the knockout, the stretcher, the concussion that ended someone's season. But the cumulative story is usually more ordinary than that. It is the steady accumulation of getting your bell rung, over and over, across a career that may have started in grade school. Each individual hit felt survivable, and it was. The concern is what the pattern can leave behind once the whistle stops blowing for good.

This matters because the effects can surface long after you have hung up the pads. Research following people over time found that roughly half of those who took a bell-ringing hit are not fully back to baseline years later (TRACK-TBI, 5-year outcomes). That gap does not always look like a headache or a memory problem. Sometimes it looks like a mood that will not lift, a flatness you cannot explain, or a version of you that your family quietly misses.

Why the mood part gets missed

Here is the connection that often goes unnoticed. A history of head impacts is one of the more overlooked risk factors for depression, and it is a risk that persists. People with a bell-ringing hit are more than three times as likely to have depression, and that elevated risk carries on for years (Beaton et al., 2020, Frontiers in Neurology). The problem is that by the time the low mood shows up, the old hits feel like ancient history. Nobody connects a rough season from fifteen years ago to how you feel on a Tuesday morning now.

So the depression gets treated the way most depression gets treated, with a standard antidepressant aimed at serotonin. For a lot of people that is the right tool. But for depression that traces back to old head impacts, it often is not enough. A meta-analysis found that antidepressants given after a head impact showed no significant difference from placebo (Foreman et al., 2019, J Head Trauma Rehabil). That is not a knock on you or your effort. It can mean the depression is running on a different system than the one those medications are built to reach.

A different engine underneath

Most common antidepressants work on serotonin. But there is growing understanding that depression linked to old head impacts can run partly on a separate system called glutamate, the brain's main signaling chemical. If the trouble sits in that system, a serotonin-focused medication can quietly miss it, no matter how faithfully you take it or how many you try. This is one reason the search for repeated concussions athletes so often ends in frustration, with a stack of prescriptions that never quite landed.

This is also where ketamine and esketamine enter the picture, and it is worth being precise about why. They act on that glutamate system rather than serotonin, with effects that can be measured in hours rather than weeks, and they appear to open a 24 to 72 hour window of heightened neuroplasticity, meaning a period when the brain is more adaptable (Zanos and Gould, 2018, Molecular Psychiatry). To be clear about what that is and is not: Spravato (esketamine) is FDA-approved for treatment-resistant depression. It is not a treatment for a concussion, and a head-injury history is a risk factor for hard-to-treat depression, never an indication for ketamine by itself.

The other things that ride along

Old head impacts rarely travel alone, which is part of why the whole picture can be confusing. If several of the following sound familiar, it may be worth having someone look at them together rather than one at a time:

• Sleep that never fully resets. Sleep disorders affect somewhere between roughly 30 and 70 percent of people with a head-injury history, and poor sleep feeds low mood in a loop.
• A flat, unmotivated feeling that hormones can drive. Up to about one in six people develop a hormone deficiency after a hit (pooled prevalence near 16.8 percent), which is easy to mistake for plain depression.
• Mood and focus that shifted and never came all the way back, even years after you stopped playing.
• A sense that standard treatment helped a little but never reached the core of it.

None of these prove anything on their own. Together, though, they form a pattern, and a pattern is exactly the kind of thing that benefits from being read by someone trained to read it.

Reading the whole story

There is a heavier statistic that deserves care rather than alarm. A concussion history has been linked to elevated odds of death by suicide (Erlangsen et al., 2018, JAMA). If your mood has gone somewhere dark, please treat that as worth immediate attention, not shame. You can reach the Suicide and Crisis Lifeline any time by calling or texting 988. Reaching out is a sign of strength, and support is available right now.

The point is not that an old hit doomed you to anything. The point is that your history is information, and information changes what a good evaluation looks for.

The reason a proper evaluation matters is that it can separate the threads that ordinary care tends to blur together: mood, sleep, hormones, and how your particular history fits into all of it. A clinic that has neurology on staff has the diagnostic lens to ask why standard care may have missed something, rather than simply prescribing the next medication in line. That is a capability, not a promise, and it is meant to answer a question rather than sell you an outcome.

If you spent years absorbing hits and now find that the low mood will not move the way everyone expected it to, that connection is at least worth understanding. An old head injury is a piece of the story, and a proper evaluation from a clinic that has neurology on staff can look at this and help you see where you actually stand.