It's generally believed that the human brain is the most complex object on Earth--certainly more complex than even the most powerful supercomputers. However, we've learned from experience that the more complex a system is, the more there is to go wrong. To keep the brain from failing in myriad ways, evolution has selected for a brain that, through a combination of redundancy and plasticity, is fault-tolerant. In other words, the brain can continue to operate normally (or more precisely, within a range of normality,) even with some damage. That damage may come from genetics, environmental factors such as pollution, or physical injury such as concussions, hemorrhages or tumors.
When the brain sustains damage beyond its capacity to compensate for, the result is mental illness. Given the brain's complexity, most human brains are already operating at or near the limits of normality just from compensating for the normal damage that accumulates throughout life. (In the brain, only the olfactory bulb and the subventricular zone contain nerve cells that regenerate in adults.) That's one reason why some neuroscientists theorize that conditions such as schizophrenia have both a genetic and environmental basis. For example, having a genetic predisposition to schizophrenia is a necessary but insufficient condition for a patient to start showing symptoms; an environmental stressor, or normal age-related changes, appears to be required in order to actually trigger the condition.
As we put more of a cognitive load on ourselves, we may very well be pushing our brains beyond their ability to compensate:
- Only twenty years ago, we were able to cope with the flow of incoming information, but today, we're continuously bombarded with text messages, emails, tweets, alerts and social media posts via our smartphones, tablets and PCs.
- We have to decide what to pay attention to, what to ignore, and what to postpone. For the messages we pay attention to, we have to understand them and decide how to respond.
- Despite the long-term recovery in the U.S. economy, employment opportunities remain diminished for recent college graduates and middle-aged workers. In addition, with the shift from permanent to contract jobs, even people who are employed need to be constantly searching for new jobs in preparation for when their contract expires or is terminated.
- The sharing economy (for example, companies like Uber and Lyft) is changing the nature of work from fairly regular schedules with reliable incomes to demand-driven work with both unpredictable schedules and income.
Technology can help with some of the added stressors: For example, automatic filters can screen out spam and organize incoming messages by priority, and newer cars have multiple sensors that can help prevent accidents. However, technology is doing far more to add to the cognitive load than it's doing to relieve it. In addition, the change in the nature of work from semi-permanent to temporary and demand-driven is unlikely to be reversed. Therefore, the amount of environmental stress will continue to rise.
My hypothesis is that we're likely to see a rise in mental illness as a result of these stressors--most likely in the forms of depression, anxiety disorders, domestic violence and violent crimes outside the home, inability to hold onto jobs not caused by the inherent transitional nature of temporary work, and suicide. Interruption-free weekends or smartphone-free vacations, which are still seen as unusual, are likely to become commonplace self-therapies to deal with the consequences of ever-increasing cognitive loads. In short, we need to become aware of the increasing cognitive stress that we're subject to, and come up with strategies for coping with the stress.