For many teens, the world seems to be a foreboding place. Rising sea levels, housing and economic crises, and looming threats of famine, drought and war are all imposing giants on the horizon of Generation Z’s consciousness. These issues pose existential threats to humanity’s survival within Generation Z’s lifetime, and with so many terrifying questions weighing on the minds of teens worldwide, rates of mental illness among teenagers have skyrocketed in recent years.
Statistics from the World Health Organization (WHO) note a nearly 15 percent increase in diagnoses of mental health disorders worldwide over just the past 10 years. Another set of studies conducted by the American Psychological Association (APA) found that depression diagnosis in teens has increased by more than 50 percent from 2005 to 2017, and that there has been a 71 percent increase in episodes of severe psychological distress among teens over that timespan.
According to the National Institute of Health (NIH), one in five teens in the U.S. struggles with Major Depressive Disorder (MDD). The NIH also found that more than one in three teenagers in the United States struggle with some type of anxiety disorder, most often Generalized Anxiety Disorder (GAD). GAD’s broader feelings of worry, self-doubt, and poor self-esteem often accompany MDD’s characteristic loss of energy, loss of motivation and extreme social isolation.
The APA also found that diagnoses with MDD, GAD and other mood disorders were highly correlated with an increase in suicidal ideation and more frequent suicide attempts; behind accidents, suicide is the second-highest leading cause of death for young adults ages 15-29. In their analysis, they listed economic recessions, the COVID-19 pandemic, social isolation, population growth and global warming as active contributing factors for the world’s increase in mental health disorders.
But, the outside world is not the only thing that influences rates of mental illness. Scientists have spent decades discovering how an individual’s biology might play a role in their mental illness, too.
It has been well-documented that victims of depression and anxiety can experience fundamental changes in their brain chemistry, from lower levels of important mood-regulating neurotransmitters to reduced brain volume. These extensive biological changes to the brain’s structure and chemistry can lead to memory loss and permanent fatigue, eventually establishing a vicious cycle of negative thoughts. Such changes are also more severe in teenagers, whose ever-changing brains are especially prone to mood swings and self-deprecating thoughts.
Before becoming a full-time clinician ten years ago, University of Wisconsin-Madison neuroscientist Jack Nitschke and his colleagues decided to use Functional Magnetic Resonance Imaging (fMRI) technology to study the effects of disorders such as Post-Traumatic Stress Disorder (PTSD), MDD and GAD on the brain. His team took a particular interest in the brain’s response to anxiety, and studied the reactions of patients when exposed to anxiety-inducing stimuli.
In order to measure anxiety in patients, Nitschke’s team used what psychologists call “instructed associations” to mimic anxiety in the lab. Volunteers were instructed to stare at a computer screen, which would then display an image of a minus sign, circle or question mark. If the patient was shown a minus sign, the screen would follow up shortly afterwards with a disgusting or unsettling image, such as the aftermath of an accident. But, if the patient was shown a circle, the follow-up image would simply be something neutral, like a salt shaker. Alternatively, if the patient was shown a question mark, the following image could be either.
With the question mark creating a feeling of uncertainty as to what would come next, Nitschke’s experiment was designed to induce mild anxiety in patients about what image was going to follow the question mark’s appearance. His team proceeded to use fMRI scans to measure brain activity after patients were shown the question mark, in an attempt to see what areas of the brain were most involved in the anxiety response.
“When I got into graduate school in the 1990s, [fMRI] technology was a new invention. I was fascinated by the idea of being able to use this technology to understand what’s happening inside someone’s brain when they experience [anxiety],” Nitschke. “These are issues that cause a lot of suffering for people, and it promised us a lot of insight into how to help them.”
Nitschke’s team discovered that when patients were shown the question mark, their amygdalas and insulas (brain areas involved with fear and anxiety responses) demonstrated high activity. This increased level of activity indicated that their brains were anticipating the appearance of a disturbing image, and experiencing a surge of fear-inducing hormones after seeing the question mark.
Nitschke continued on the focus of his work, describing his research methods.
“These tasks were designed to measure how people respond to that anxiety-induced fear. As an emotion, anxiety is very strongly related to our anticipation of something bad happening, and the key to our experiment was to find a way to create that in a lab,” Nitschke said. “That lets us see what areas of the brain people activate when they feel anxious about the future, how different people with different kinds of anxiety react, and it gives us a glimpse into how their brain went about dealing with it.”
Nitschke’s team also used the neutral stimulus (the circle) in order to compare the brain’s response to anxiety about bad events versus neutral events; they were able to determine if anticipation of an aversive image would cause more worry than a neutral one. Their results revealed that participants were more often hooked on the negative images, with 75 percent of them overestimating how often aversive pictures followed uncertain cues.
“But,” Nitschke acknowledged, “the work hasn’t been as successful as I’d hoped it would be. There’s been a lot of setbacks, and quite frankly, the biological level isn’t the perfect level of analysis. There’s brain areas that are clearly, clearly involved in anxiety and depression, but it’s hard to get a full answer from biological measures alone.”
Ten years ago, Nitschke transitioned from his research to becoming a full-time clinical psychiatrist at UW-Madison, and now sees about thirty patients a week. The primary thing that he explains to his patients has little to do with their brain’s structure; instead, he teaches patients about how their brains can change over time.
The past twenty years of brain research have led to marvelous scientific advances in understanding what researchers call “neuroplasticity.” Simply defined, neuroplasticity is the brain’s ability to form new neural connections, grow new neurons and adapt to new environments. Repetition of activities, such as daily practice, employs our neuroplasticity and strengthens our memory networks.
Recent scientific interest in neuroplasticity has led to an explosion of neuroplasticity-based therapy treatments for mental health disorders. Plasticity-based therapy has been explored in various studies that are currently attempting to use it to treat neurodegenerative diseases such as Alzheimer’s disease and multiple sclerosis. These therapeutic approaches employ repetition of tasks and thought exercises in order to improve a patient’s self-esteem, train their memory, or help them process a traumatic event.
“What I want people, especially teenagers, to understand is this: whenever you repeat and do something over and over again, your brain is developing networks and connections for that, and it helps you get really good at doing whatever it is that you’re doing,” Nitschke said. “If you like math, or chess, or sports, and you do it a lot, the number of repetitions gets your brain to make connections and makes you better,” he continued.
Nitschke notes that neuroplasticity isn’t always helpful, however. The same principles that apply to learning via repetition also apply to self-critical thoughts, and many people who struggle with mental disorders often emotionally spiral due to their neuroplasticity reinforcing negative thoughts.
“Neuroplasticity doesn’t care one bit about morals, values, or ethics. It can’t tell which thoughts are harmful or not, or which thoughts aren’t helpful to reinforce. All it does is encode thoughts that are repeated over and over again,” Nitschke remarked.
Nitschke’s neuroplastic approach to therapy is part of a much larger shift in the healthcare industry in how healthcare providers handle providing therapy to patients. Therapists today seek to work in tandem with patients’ brain biology by encouraging healthy coping mechanisms and strengthening them through repeated self-affirmations, in order to make use of neuroplasticity’s benefits.
“We can break that cycle of reinforcing negativity and start creating healthy, helpful neural networks instead,” Nitschke said. “Beyond anything else, it’s about repeating positive thoughts, and getting rid of bad influences to break the harmful cycles.”
Though biology may not have all the answers when it comes to the vastly complex field of therapy and mental illness, studying the biology of the brain has given scientists and therapists alike important insights in how to help patients. Taking a neuroplasticity-based approach to therapy offers a new perspective for therapists on how conscious efforts to change affect the brain, and perhaps most importantly gives victims of these mood disorders a way to be an active participant in their own healing.
