Decoding the Link Between Immunity, Mental Health, and Addiction

By Ashli Landa

The power and promise of the immune system is at the heart of Dr. Phillip Rivera’s recently received 2023 Scialog Collaborative Innovation Award, sponsored by the Research Corporation for Science Advancement (RCSA). The assistant professor of biology and a team of researchers were individually awarded $50,000 in funding for their project proposal, “The Mystery of Heavy Drinking: Exploring the Roots of Alcohol Dependency.”

Rivera’s work is at the intersection of immunology and the learning/memory process. As a “psychoneuroimmunologist,” he aims to understand how, and to what extent, our immune system impacts behaviors and cognition. His hope is that it may be possible to utilize the immune system for a wide variety of applications—from predicting neurodegenerative diseases to understanding how space radiation affects astronauts.

With this grant, Rivera and his team are particularly interested in the molecular biology behind alcohol dependency. He’s studied addiction for over a decade now, namely because of its unique utility for analyzing the interactions between memory, behavior, and immunology.

“I use addiction as a tool to study why certain behaviors occur in certain individuals, and not in others,” he says. “Why do some individuals become addicted, and not others? Neurologically, addiction is a learning process, but the other thing that is really involved is your immune system, which can regulate how things are learned depending on its state.

“My colleagues and I want to address this question of why some drugs become so ingrained in our minds and consciousness, and tease out the molecular signatures during the process of learning to become addicted,” he says.

With current research into immune profiles in blood to detect susceptibility to potential health issues, Rivera wonders if inflammatory-related biomarkers could predict predisposition to addiction, or resilience to it. The research could lead to considerable advancements in the addiction treatment and recovery field because like addiction, recovery is also a learning process, in which the brain adjusts to withdrawal.

“Since the recovery process is new learning, and the immune system plays a role in learning and memory, maybe there are ways to alter the immune system to facilitate recovery,” he says. “It absolutely can tie in to how we think about individuals with substance use disorders and the recovery process.”

Rivera says his work is often “top-down, instead of bottom-up,” meaning he first looks at addiction behaviors and then analyzes the brain and body to see what kinds of immune responses are involved. He’s looking forward to what his colleagues from the Scialog conference will also bring to the table from their analyses of exosomes, tiny bubbles released from cells that act like mail carriers, delivering messages and materials between cells to help them communicate and function properly.

RSCA’s Scialog (a portmanteau of “science” and “dialog”): Molecular Basis of Cognition initiative brings together early-career researchers from a variety of disciplines, approaches, and methodologies, and aims to “accelerate breakthroughs by stimulating intensive interdisciplinary conversation and community building” by encouraging participants to form teams, according to RSCA. The teams then propose “high-risk, high-reward” projects for funding opportunities.

The atypical experience—which Rivera describes as “speed-dating for scientists”—felt particularly promising for him, expressing that science can often feel isolating. Bringing together individuals with such a variety of expertise to address a specific problem, he says, is “the way science should be.”

“I think I’m most excited about collaborating with my colleagues. Being able to come together and bring our minds together—that’s the beauty of science,” he says. “And being able to bring in our students for the experience is something I’m really looking forward to.”

Incorporating opportunities for undergraduates is a crucial component for Rivera. “I include undergraduate research in every grant I write,” he says. “If I can help an undergraduate understand some of the things I’m researching and gain more experience along the journey, that’s wonderful.

“Seeing my undergraduate students writing papers, going to national conferences, presenting their work, and now getting to hear from them as they go on to postgraduate schools and programs—it’s so rewarding to know that I could help them get to where they want to be after Macalester.”

Even if you’re not a biology student or psychoneuroimmunologist like Rivera, there are still lessons the layperson can take away from all this research into the immune system.

“The pandemic highlighted the importance of how interconnected we really are,” he says. “Social contact is significant in regulating stress, which is linked to inflammatory responses our bodies produce. As humans, we need to have, and be in, community.

“It’s important to take care of yourself no matter who you are. Understanding what fills your cup, what brings you joy, and what rejuvenates you, is key.”