8.6: Brain Functioning

The brain at midlife has been shown to not only maintain many of the abilities of young adults, but also gain new ones. Some individuals in middle age actually have improved cognitive functioning (Phillips, 2011). The brain continues to demonstrate plasticity and rewires itself in middle age based on experiences. Research has demonstrated that older adults use more of their brains than younger adults. In fact, older adults who perform the best on tasks are more likely to demonstrate bilateralization than those who perform worst. Additionally, the amount of white matter in the brain, which is responsible for forming connections among neurons, increases into the fifties before it declines.

Emotionally, the middle-aged brain is calmer, less neurotic, more capable of managing emotions, and better able to negotiate social situations (Phillips, 2011). Older adults tend to focus more on positive information and less on negative information than those younger. In fact, they also remember positive images better than those younger. Additionally, the older adult's amygdala responds less to negative stimuli. Lastly, adults in middle adulthood make better financial decisions, which seems to peak at age 53, and show better economic understanding. Although greater cognitive variability occurs among middle adults when compared to those both younger and older, those in midlife with cognitive improvements tend to be more physically, cognitively, and socially active.

COVID-19 and Brain Effects:

In addition to the main medical complications of COVID-19, sensory and mental health symptoms are also observed suggesting that the virus directly affects the central nervous system. Taquet et al. (2021b) reviewed the health records from 69 million individuals, 62,354 of whom had a diagnosis of COVID-19. They found an increased risk of being diagnosed with a first mental health disorder for those having been diagnosed with COVID-19 compared to those diagnosed with other health disorders, such as respiratory tract infections or influenza. The risk was greatest for developing anxiety, insomnia and dementia. Additionally, they found that having a diagnosis of a mental health disorder in the year before the COVID-19 outbreak was associated with a 65% increased risk of COVID-19. The authors concluded that the virus may affect the brain directly or through other biological pathways, such as immune responses.

Speth et al. (2020) found that anxiety and depression were associated with those diagnosed with COVID-19 who experienced a loss of taste and smell, but not with those who experienced nasal obstructions, excessive mucus production, fever, cough, or shortness of breath. This suggests that the virus is infecting olfactory neurons and entering the central nervous system through the olfactory tract. Similarly, Taquet et al. (2021a) reviewed more than 236,000 COVID-19 patients and found that close to 34% of those who survived the virus were diagnosed with neurological or mental health conditions within six months of the initial infection. The authors found that those who survived COVID-19 had a higher risk of these conditions than those who recovered from a severe case of the flu, thus concluding that COVID-19 does enter the brain. According to Schoenberg (2021), a rare but serious condition known as post-COVID psychosis occurs within months of infection, and it is characterized by extreme fear, anxiety, hallucinations and/or delusions.

According to Schoenberg, a recent British study found that out of 153 people experiencing psychiatric problems after COVID, 10 exhibited new onset psychosis. Theories to explain the psychosis include the virus causing direct damage to the brain as some scans have shown lesions in brain areas linked to psychotic symptoms. Additional theories include that the virus causes changes in blood flow to the brain, as well as the virus triggers an immune system response. Other researchers (Chacko et al., 2020; Ferrando et al., 2020) have also concluded that after invading the central nervous system, the inflammatory response to COVID-19 infection ("cytokine storm") is thought responsible for the psychosis. If a COVID-19-psychosis relationship exists, treatment of the psychotic symptoms with antipsychotic medication, while also treating the underlying COVID-19 infection and its associated inflammation will be needed.