Stress not only affects how people feel in the moment. According to a research conducted in Alzheimer’s Prevention Clinic in the Center for Brain Health at Florida Atlantic University’s Schmidt College of Medicine, it also affects mental and cognitive health throughout one's lifetime. Recent studies in the Journal Pediatrics suggest that experiences such as discrimination in young adulthood, early personality traits, and long-term pet ownership may play a substantial role in brain aging. 

At the center of this process is the brain's stress-response system, which includes regions like the prefrontal cortex, hippocampus, and amygdala. When an individual encounters a stressful situation such as social rejection or discrimination the amygdala interprets the experience as a threat. It sends signals to the hypothalamus, activating the hypothalamic–pituitary–adrenal (HPA) axis. This system releases stress hormones like cortisol and adrenaline that increases the heart rate, sensitivity, and energy to help the body respond. These systems remain active for extended periods of time when stress becomes pervasive. The long-term effects of unmanaged stress have been highlighted by the correlation between longer conditions of this process and anxiety, depression, memory loss, and accelerated aging.

A discrimination study based on the psyche published in Pediatrics found that young adults who frequently experienced discrimination based on race, age, sex, or appearance had a significantly higher risk of developing mental health issues like anxiety and depression. Researchers such as Yvonne Lei, an author at the University of California, Los Angeles’ David Geffen School of Medicine, emphasized that the ages 18 to 28 are a particularly vulnerable period when long-term stress can leave lasting psychological effects. “With 75% of all lifetime mental health disorders presenting by age 24, the transition to adulthood is a crucial time to prevent mental and behavioral health problems,” said Yvonne Lei. Because social stressors like discrimination are unpredictable and uncontrollable, neuroscientists note that they are especially damaging. In contrast to temporary difficulties, constant social rejection keeps the body on alert. Higher levels of stress hormones, such as cortisol, can cause increased reactivity to stress in the future, enhancing an individual's sensitivity to mental health issues in later life.

However, long-term effects of stress become apparent later in life than disappearing with age. A study published in the Journal of Personality and Social Psychology found that certain personality traits may increase the likelihood of cognitive impairment in later life.“The accumulation of lifelong experiences may then contribute to susceptibility of particular diseases or disorders, such as mild cognitive impairment, or contribute to individual differences in the ability to withstand age-related neurological changes,” said Dr. Richard Isaacson, director of the Alzheimer’s Prevention Clinic in the Center for Brain Health at Florida Atlantic University’s Schmidt College of Medicine. In contrast, individuals with more extroverted traits tended to maintain healthy cognitive function for a longer period. Experts presented that stress is the significant connection between the two findings. Rather than isolated incidents, ongoing discriminatory acts, such as chronic stress, restrain the brain’s stress-response network. Emotional reactions are common in people suffering from anxiety, and researchers think that excessive stress reactions could promote cognitive decline.

It is interesting to note that not all long-term effects are detrimental. A separate study by clinical neuroimmunologist Dr. Tiffany Braley, an associate professor of neurology at the University of Michigan, showed that owning a pet for five years or longer was associated with better memory retention in older adults. Prior research has also identified associations between interactions with companion animals and physiological measures of stress reduction, including reductions in cortisol levels and blood pressure, which in the long term could have an impact on cognitive health,”  she said. The researchers suggested that companionship, reduced stress, and increased social interaction will ultimately preserve brain health. These factors help regulate stress responses by demonstrating that supportive environments and lifestyle choices can strengthen the brain’s resilience over time. 

When examined as a whole, these studies imply that cumulative experiences such as social treatment during childhood to personality traits and decisions later in life are what shape mental and cognitive health rather than a single event. Social treatment early in life, emotional response patterns, and everyday life decisions all influence how frequently and intensely the brain is placed under stress. By recognizing the interaction of early experiences and supportive relationships in real life, individuals can better promote long-term psychological well-being and healthier brain aging.