Researchers conducted a review of 56 clinical trials, representing 4,060 participants, that tracked changes in immunity over time during the course of psychotherapy. They looked at eight different psychosocial interventions—such as CBT, behavior therapy, cognitive therapy, and psychoeducation—as well as seven markers of immune system function, including inflammation, antibody levels, viral load, and natural killer cell activity. They found that across the interventions, there was a strong association with enhanced immune system function, and that persisted for at least six months following treatment. The associations were most significant for CBT or combined interventions, but as a whole, all intervention types provided some level of improvement in immune system function, according to study author Grant Shields, PhD, at the Center for Mind and Brain at University of California, Davis. There are long-held stigmas attached to people seeking help—such as psychotherapy—for their mental health. Understanding the numerous benefits can go a long way toward fighting those stigmas and letting people know that therapy can help anyone, even those without a diagnosed mental health condition.

The Inflammation Connection

The reason that psychotherapy, and particularly CBT, might have such a direct effect on immune function was not part of the study, says Shields. But the assessment of inflammation markers gives a clue about what the mechanism might be. Inflammation has often been connected to numerous health issues, including cognitive and mental disorders from dementia to depression. Commentary published in Frontiers in Immunology highlights that while many factors play a role in the development of depression, there have been links to increased inflammatory activation of the immune system, which affects the central nervous system. Those researchers note that antidepressants have been shown to decrease inflammation while higher levels of inflammation can lower treatment effectiveness. In terms of immune function, inflammation is part of the body’s natural defense mechanism, and it plays a role in healing. But when it goes into overdrive, that’s when the health issues begin to crop up. Keeping it regulated in a way that harnesses the power of inflammation without letting it surge is an important part of maintaining health at every level, says Shields. “The results of this study underscore how much mental and emotional issues can affect physiological reactions, and that goes both ways,” says Ian Sadler, PhD, psychologist at Columbia University Irving Medical Center. “For example, we often see people with compromised immune function and chronic health problems facing mental health challenges. Addressing physical health will have an impact on mental wellbeing, and vice versa.”

Lifestyle Factors Can Play a Role

Addressing emotional and mental difficulties can also affect the immune system, including inflammation levels, because it could prompt changes in behavior, says Lauren Bylsma, PhD, assistant professor of psychiatry and psychology at the University of Pittsburgh. For example, if someone is empowered through therapy, they may be more inclined to make changes such as:

Exercising moreEating healthier foodsPursuing more social interactionsCreating a better sleep scheduleImplementing anti-stress strategies

All of these shifts have been shown in past research to affect immune system function, in part because they reduce inflammation but also because they improve gut health—a major aspect of psychological well-being, Bylsma says. “It’s all interconnected in terms of how your mind and body are responding,” she notes. “Generally, when people start feeling better mentally, they start to implement behaviors that support their health. And that begins to build on each other.” “These systems all work together, and it starts with small changes in some behaviors, along with setting reasonable goals, and then you’ll likely find that it gets easier to adopt healthier behaviors from there,” says Bylsma, adding that a first step of psychotherapy could be the kickoff needed to start this ripple effect. For more mental health resources, see our National Helpline Database.