Why Doesn't the Same Thing Affect Everyone the Same Way?

Two students get almost identical marks on a test they thought they had done well on. One is annoyed, complains to a friend, eats something and moves on. The other keeps thinking about the mark all evening. By bedtime, one bad test has somehow recruited last month's bad test, an awkward conversation from Tuesday and several unrelated worries into an emergency meeting. Same event. Very different response.

If mental health were simply caused by what happened to us, similar experiences should produce similar reactions. They don't, because your brain never experiences an event by itself. Your previous experiences, current stress, relationships, physical state and thoughts all arrive at the event with you. Your brain also compares what is happening now with memories of what happened before. “This is disappointing” feels quite different from “this proves I'm a failure.” The event may be identical, but the brain interpreting it is not. Mental health develops inside this much bigger system. Life experiences matter, but so do relationships and social conditions, biology, previous development and how we think about what happens. Scientists therefore do not have a good basis for reducing something as complicated as depression to one brain chemical being too high or too low. The brain uses chemical messengers, but they operate inside much larger networks and body systems. Stress, sleep, genetics, relationships, experiences and environments can all matter. Mental health is more like a constantly changing conversation among systems than one chemical dial that has slipped out of position.

Your Brain Learns From What Happens

Your brain learns skills through experience, but it also learns about the world itself. Suppose you repeatedly face manageable challenges and have people around you who help when things become difficult. Your brain gathers useful evidence: Hard things happen. I can get through some of them. Other people can help. Those lessons do not make future stress disappear. They become part of what your brain brings into the next difficult situation.

Repeated overwhelming experiences can teach different lessons. The body's stress-response systems may become activated often or stay activated for longer, particularly without enough support. Over time, prolonged stress can affect sleep, attention, emotions and other parts of health. Researchers at Harvard emphasize the importance of supportive relationships with caring adults during development. Another person cannot erase a difficult experience, but support can change the conditions in which a developing brain and body deal with it. (developingchild.harvard.edu). That makes the social part of mental health more important than it might sound. Humans pay enormous attention to acceptance, rejection, belonging and whether somebody has our back. Conflict, bullying and isolation can add stress, while safe relationships can provide reassurance and practical help. Grade 8 is also an unfortunate age to discover that one person's strange facial expression can occupy a surprising amount of your brain for the next two hours. Our social worlds matter because our brains treat relationships as important information.

Thoughts matter too, but they are only one part of the system. Two people can make the same mistake and tell themselves completely different stories about it. One thinks, That went badly. I'll figure out what happened. Another thinks, I always mess everything up. Those thoughts can influence what happens next, but that does not mean somebody can simply think their way out of a mental health challenge. Biology, experiences and circumstances do not disappear because someone says, “Just stop worrying.”

What About Experiences From Years Ago?

Early experiences matter because childhood and adolescence are periods of enormous development. Brain networks are changing, stress-response systems are learning from experience, and relationships help shape what a person expects from other people and the world. Difficult experiences can therefore influence development, especially when they are severe, repeated or happen without enough support. But influence does not mean destiny. Development continues, and later relationships, environments and experiences matter too.

Generational trauma describes ways trauma affecting one generation can influence generations that follow. This can happen through family experiences, relationships, living conditions, continuing discrimination or disadvantage, community experiences and other pathways. Scientists are also investigating possible biological pathways, although that is much more complicated than saying trauma simply gets “passed down” in someone's genes. A young person's future is not biologically written because an earlier generation experienced trauma. New experiences and supportive environments continue to matter.

Return to our two students and their disappointing test. One may have slept terribly, while another has already dealt with similar disappointments and recovered. One might have a friend waiting outside the classroom, while the other feels alone. Their biology, experiences, thoughts and social worlds meet the same event from different starting points. Mental health develops through an ongoing interaction between what happens to us, the people and environments around us, our biology, our previous experiences and what our brains make of it all. If what is happening inside someone can be so different from what we see outside, the next question is how we recognize when somebody may be struggling.

If what is happening inside someone can be so different from what we see outside, the next question is how we recognize when somebody may be struggling.