Part 2 Whiplash - Emotional/Behavioural Changes

Thomas Jarka
Jun 11
3 min read

So as stated in the last post, whiplash happens when the head is suddenly and forcefully thrown backward and then forward—like the cracking of a whip. This motion can strain muscles, ligaments, and vertebrae in the neck. But it's not just the neck that's affected. The violent movement can also cause mild traumatic brain injuries (mTBI), especially in the brain’s more vulnerable areas.

The Brain Takes a Hit

Even without direct impact, whiplash can jostle the brain inside the skull. This kind of trauma—often called a “coup-contrecoup” injury—can lead to concussive symptoms: headaches, memory issues, irritability, and difficulty concentrating. In some cases, people also experience changes in mood and behaviour.

Here’s where things get even more interesting: recent studies suggest these behavioural changes may be linked not only to brain injury but also to changes in gut health.

The Gut-Brain Axis: A Two-Way Street

You might’ve heard of the “gut-brain connection”—the fact that your digestive system and brain are closely linked. That’s not just a wellness trend. Science has shown that the gut and brain constantly communicate via nerves, hormones, and immune signals. When something goes wrong in one, it can affect the other.

After a traumatic brain injury (TBI)—even a mild one like those caused by whiplash—researchers have found changes in the gut’s barrier function. Essentially, the lining of the gut becomes more permeable, a condition often called “leaky gut.” This allows bacteria and inflammatory molecules to escape into the bloodstream, which can trigger widespread inflammation—including in the brain.

How This Affects Behaviour

Inflammation in the brain is a known factor in mood disorders, anxiety, and cognitive changes. So when the gut barrier is compromised after a brain injury, the brain may experience a secondary wave of damage caused by the body’s own inflammatory response.

In short: whiplash can lead to brain injury, which may disrupt gut barrier health, and that disruption can worsen behavioural and cognitive symptoms.

Some people may notice they become more anxious, depressed, forgetful, or irritable after an injury that didn’t seem serious at the time. Understanding the gut-brain link helps explain why these changes occur—and what can be done about them.

What Can You Do?

If you or someone you know is experiencing behavioural changes after a neck or head injury, here are a few steps to consider:

Seek medical advice: Don’t ignore mood or behaviour changes, even if the injury seemed minor.
Support gut health: Eating a balanced diet, reducing stress, and avoiding excessive antibiotics or processed foods can help maintain a healthy gut barrier.
Ask about anti-inflammatory approaches: Some treatments may target systemic inflammation to support both brain and gut healing.

The Bottom Line

Whiplash isn’t just about a stiff neck. It can set off a chain reaction involving the brain and gut that leads to real, sometimes serious, changes in behaviour. The good news is that science is catching up—and with awareness and the right care, healing is possible from the inside out.

Sources and Further Reading

Mayer, E. A., et al. (2015). Gut/brain axis and the microbiota. Journal of Clinical Investigation, 125(3), 926–938. https://doi.org/10.1172/JCI76304
Houlden, A., et al. (2016). Brain injury induces specific changes in the caecal microbiota of mice via altered autonomic activity and mucoprotein production. Brain, Behavior, and Immunity, 57, 10–20. https://doi.org/10.1016/j.bbi.2016.03.003
Treangen, T. J., et al. (2018). The gut microbiome after traumatic brain injury: What we know and what we need to know. Frontiers in Cellular and Infection Microbiology, 8, 240. https://doi.org/10.3389/fcimb.2018.00240
Ma, E. L., et al. (2017). Traumatic brain injury increases vulnerability to intestinal damage. Neurotherapeutics, 14(2), 298–311. https://doi.org/10.1007/s13311-017-0503-3
Sekirov, I., et al. (2010). Gut microbiota in health and disease. Physiological Reviews, 90(3), 859–904. https://doi.org/10.1152/physrev.00045.2009