Expecting Good Things Can Supercharge Your Immune System

The last thing you want to hear when you’re feeling down is something like “chin up” or “just think positive.” But there may be some merit to that approach, at least if you can channel it appropriately: according to a new study, you could placebo yourself into supporting your immune system.

In a first-of-its-kind human trial, researchers have demonstrated that consciously activating the brain’s reward system (when you’re anticipating something good happening) can significantly increase the production of antibodies following a vaccination. This could even help explain how the placebo effect works.

The Mental Gym for Your Molecules

The study, led by Nitzan Lubianiker and colleagues, utilized fMRI-based neurofeedback to see if humans could “think” their way to better health. They recruited 85 healthy participants and split them into groups: those who would try to turbocharge their reward-related brain regions, and control groups.

Inside the fMRI scanner, participants were asked to use mental strategies like recalling a happy trip or imagining a positive future to increase activity in their mesolimbic reward network. It’s not just “think happy thoughts”, but rather try to imagine tangible good things that will happen to you in the future.

The researchers were specifically looking for activity in the Ventral Tegmental Area (VTA), a tiny hub in the midbrain that serves as a primary source of dopamine. This region is the engine of the mesolimbic reward system. Participants received real-time “scores” (feedback) on how well they were activating these regions.

Furthermore, the researchers actively worked with participants. Those in the “experimental group” were shown real-time feedback on their VTA activity. They became “mental athletes,” testing out different strategies to see what made that midbrain engine rev. Some recalled memories of a great trip; others imagined achieving a goal. Meanwhile, a “control group” was trained to upregulate other parts of the brain entirely unrelated to reward.

Putting It to the Test

Once these participants had spent several sessions learning how to flex their VTA “muscles,” the researchers gave them a real-world challenge: a Hepatitis B (HBV) vaccine.

The results were stunning. The people who were most successful at boosting their VTA activity produced significantly more antibodies in response to the vaccine. It didn’t matter which group they were in; if their VTA was firing, their immune system was turbocharged. This provides the first direct evidence in humans that our “hope circuits” are literally connected to our antibody-producing machinery.

“Despite compelling clinical observations and causal evidence in animals, there has been no direct evidence of these processes in humans. Now… Lubianiker et al. provide this evidence,” reads a commentary article spearheaded by Kyungdeok Kim, an expert in the field.

They discovered that generic “happiness” or “pleasure” didn’t correlate with the immune boost. The magic ingredient was positive expectation.

It’s a subtle but key distinction. Happiness is a state of being. However, positive expectation is an active, forward-looking anticipation of a good outcome. You can’t really model the first, but you can model the latter. Simply put, you can sort of placebo yourself and give your immune system a push.

But How?

This finding helps explain the “Placebo Effect,” one of the most enduring mysteries in medicine. For decades, we have known that if a patient expects a treatment to work, they often show clinical improvement. Sometimes, this works even if they’re only taking a sugar pill. This study suggests the VTA is the bridge. By consciously generating a positive expectation, you are essentially “hacking” your reward system to send a “boost” signal to your peripheral physiology.

But why would our brains be wired this way? The researchers propose a beautiful evolutionary theory they call the “double life” of the reward system.

In the wild, chasing a reward (like hunting for food or seeking a mate) is dangerous. It involves stress, physical exertion, and the risk of injury. By linking the reward system to the immune system, nature has ensured that at the very moment we start pursuing a goal, our body begins “pre-gaming” its defense systems, boosting our somatic resilience so we can survive the challenges that come with achieving our appetitive goals.

Potential Power in Positive Thinking

The next question, of course, is if we could actually use this finding.

Take cancer immunotherapy, for instance. We now have incredible treatments like CAR-T cell therapy and checkpoint inhibitors that use the body’s own immune cells to fight tumors. But these treatments don’t work for everyone. If we could use neurofeedback to help cancer patients “rev” their reward systems before or during their immunotherapy, we might significantly improve their chances of survival.

There is also the issue of depression. We know that depression is strongly linked to a “broken” reward circuit, and it is also much more prevalent in cancer patients. This creates a vicious cycle where a depressed brain might actually be dampening the body’s ability to fight the disease. By developing tailored neurofeedback protocols, we might be able to jump-start those reward circuits and, by extension, the immune system.

But the study is small and the researchers acknowledge the limitations. They also noted that they didn’t see a massive difference in antibodies between the entire neurofeedback group and the control group.

We definitely don’t understand everything about this. Still, the potential is huge. We’re entering an era where your mental state might be considered a part of your treatment plan.

The study “Upregulation of reward mesolimbic activity and immune response to vaccination: a randomized controlled trial” was published in Nature Medicine.