Social experience rewires the brain

The authors analyzed studies in which fMRI scans were compared with information about the participants’ social relationships, and they concluded that the pattern of brain activity depends on the social experience that shaped it. Behavior that helps a person cope in one environment may be useless in another and leaves unique neural traces. Therefore, the same activity pattern cannot serve as a universal marker of health. “Health depends on experience,” Merritt explains.

A certain pattern may reflect a useful adaptation in a person without reliable support from loved ones, but in a person with a strong support network, it may indicate avoidance of contact. For experts, this is an important shift, as understanding the context helps to distinguish between illness and learned coping mechanisms, to work with the causes of depression rather than just the symptoms, and ultimately to make fewer mistakes in diagnoses and therapy selection. “This is the cornerstone of the principle ‘treat the patient, not the problem,’” commented New York‑based psychotherapist Michael Herman.

Social connections have a particularly noticeable impact on the so‑called default mode network — the brain regions responsible for recognizing others’ emotions and regulating one’s own feelings. The strength of the connections between these regions and their links to other areas change depending on a person’s past and current social experience. This explains the contradictions in previous studies: some works linked increased communication between certain parts of this network to depression, while others associated the opposite pattern with the same depression. “In one environment, more connections in this network are good, but in another, they are effectively harmful,” Merritt notes.

The same logic applies to behavior. A psychotherapist may mistakenly identify a useful mechanism as a symptom: “The doctor may see a person who is wary, hypervigilant, or relies only on themselves — and decide that this is a problem that needs to be fixed,” Herman suggests. But the distance in the relationship may have been a defense mechanism after repeated betrayals. The social context also explains why people with similar symptoms need different recommendations: one may benefit more from learning to set boundaries, while another may need to gradually rebuild trust in people. As trauma specialist Diane Poole Heller notes, encouraging closeness only makes sense if its quality and safety are understood.

The authors also describe the feedback loop between experience and behavior: people who have experienced reliable support during difficult periods are more likely to accept help, and every positive social interaction strengthens resilience to future stress. Those with weaker attachment tend to withdraw and fail to receive the necessary support. That is why, according to Herman, it is important for the therapist to take the patient’s past into account. Psychological difficulties make it hard to overcome the belief that seeking help is useless, and the lack of close connections hinders recovery.

One possible mechanism linking the social environment to brain function is the stress response. The hormone cortisol is released in stressful situations, and, according to Merritt, even physical support from another person—for example, a hand touch—can reduce its levels. When a person feels supported, stress reactions weaken and the sense of threat decreases—“and even real pain is felt less intensely,” Herman adds. Over time, stress hormones change the intensity of connections between brain regions, and it is these patterns that are recorded by tomography. Mental health consultant Paul Hockemeyer adds that accumulated emotional experience forms an “unconscious map” that the brain uses to assess whether new people can be trusted.