The Teenage Brain: A Neuroscientist's Survival Guide to Raising Adolescents and Young Adults

Adolescence is the time of life when the signs of around 50% of adult mental illnesses first appear. However, as most teens experience mood swings, it can be difficult to distinguish disorders from “normal” teenage behavior. Jensen advises parents to be alert to an exacerbation of mood in teenagers, such as sadness, anger, or irritability, that continues for more than two weeks. If parents suspect a mental disorder, they should seek medical help as early as possible.

Depression is hard to detect as teenagers often seem withdrawn due to their constant engagement with technology. The author states there is usually more than one warning symptom and recommends that parents look out for changes in eating routines, increased risky behavior, or social isolation. Depressed adolescents respond more rapidly to medication than adults. However, some antidepressants, tolerated well by adults, may increase suicidal impulses in teens. Jensen shares the story of a colleague whose older teenage boy was prescribed Zoloft for depression and hanged himself in his closet. His younger brother heard his sibling dying from the next room and, 10 years later, also hanged himself. The author reveals that there are other “atypical antidepressants” that can be prescribed for children and adolescents. In the USA, antidepressants now come with a “black-box” warning of potential side-effects.

Anxiety is a common feature of the teenage years. However, Jensen explains that a disorder entails a higher degree of anxiety that will “interfere with normal functioning” (200). Adolescents may become withdrawn or, conversely, behave recklessly. Physical symptoms include stomachaches, headaches, fatigue, trembling, sweating, and hyperventilation. Anxiety disorders often involve dysfunction of the brain’s frontal lobes and include social phobias, obsessive-compulsive disorder (OCD), panic disorder, and agoraphobia. Jensen emphasizes that the sources of adolescent anxiety differ from those that trigger stress in adults. Instead of worrying about money, health, family, and work issues, teens tend to focus on “friends and school” (201).

Signs of bipolar disorder often emerge in the mid-teens and are more common in females. However, symptoms differ from those in adults. Adolescents are less likely to experience “pure mania,” often displaying a combination of “mania and depression” (192). Teenagers have shorter periods between depressive and manic episodes and have a greater tendency toward aggression, irritability, and paranoia. Stress is a major risk factor in the development of schizophrenia. A family history of the illness gives adolescents a “1-in-10 chance” of also developing it. If marijuana use is added to the equation, the risk doubles to one in five. Distinguishing features of schizophrenia include odd speech patterns, hallucinations, psychosis, and a disconnection from reality.

Jensen describes a meeting of the Society for Neuroscience that she attended in 2010. Also speaking at the meeting were actress Glenn Close, her sister Jessie, and her nephew Calen. Close described how her sister Jessie showed the first symptoms of bipolar disorder and schizoaffective disorder in high school through mood swings and impulsivity. After dropping out of school in 10th grade, Jessie’s life took on a pattern of hospitalization, suicide attempts, and failed marriages. However, Close’s sister was not diagnosed until the age of 45. Jessie also spoke at the meeting, admitting that when her son, Calen, showed the same signs of mental illness, she assumed that he was going through a difficult adolescence. Finally, Calen addressed the meeting, describing the delusions he suffered as a teen. Calen pointed out that mental illness is particularly challenging for teenagers, as it arises at a time when peers lack empathy and the ability to give support.

The author reveals that suicide is the second most common cause of death for adolescents after automobile accidents. The author details the case of 19-year-old Elizabeth Shin. The day before ending her life in 2000, Shin’s journal entries were alternately morbid and light-hearted. Her family visited her at college that day, and during dinner, Shin discussed plans for a trip to South Korea. The next day, the teenager died after setting her clothes on fire. Jensen suggests that while Shin’s method of ending her life was unusual, her case is also typical of suicidal teens. She could not see a future beyond her state of despair but showed no outward signs of her intentions to her family.

Jensen points out that contemporary teenagers are the first generation to grow up using such a wide range of digital devices. She suggests that this makes them vulnerable to new dangers. The author recounts receiving an email from a 26-year-old man who became addicted to computers as a teenager. Jensen argues that the young man’s story is unsurprising, as the teenage brain is more vulnerable to addiction of all kinds. Like any other addictive substance or activity, technology offers the promise of pleasure and therefore prompts the release of dopamine. In an experiment, a group of students from 12 countries was asked to forego all digital media for 24 hours. Reporting their experiences afterward, many of the students used language associated with drug or alcohol withdrawal.

Jensen estimates that, by the age of 21, the average young man has spent 10,000 hours playing video games. Research into the effects of gaming indicates that moderate play can enhance the brain. For example, one study suggested that casual gaming increased the size of the brain areas responsible for memory and “visuospatial skills.” However, research into excessive gaming shows negative effects on the brain. MRI scans of obsessive gamers displayed the type of irregularities in the brain’s gray and white matter, usually found in individuals who are addicted to drugs or alcohol. Areas of the brain that regulate risk-taking were discovered to be smaller, and there were fewer connections to the frontal lobes than in moderate gamers.

Opinion varies as to whether excessive technology use should be recognized as a genuine addiction. However, the CRC Health Group recognizes Internet addiction and gives a list of behavioral and physiological symptoms. Warning signs in adolescents include spending all leisure time online, declining grades, falling asleep at school, irritability when not online, headaches and vision problems, carpal tunnel syndrome, insomnia, skipping meals, and neglecting personal hygiene. The author suggests that online gambling poses a particular threat to adolescents as it feeds two addictions in one. Despite the minimum legal gambling age in the USA, under-18s can still use sites hosted in countries with no age restriction.

Jensen suggests that adolescents’ constant engagement with the digital world impairs their ability to concentrate. While teenagers believe they accomplish more when working while also using digital entertainment devices, research shows that learning is inhibited, and tasks like homework ultimately take much longer. Studies also suggest that multitasking releases more stress hormones in the body. The author concludes that teenagers falsely believe that multitasking is helpful as it makes tasks more enjoyable, for example, reading while also watching TV. She advises parents to steer teenagers away from this habit by encouraging them to prioritize, create lists, and organize homework upon returning from school. The reward of TV or computer time should only be offered once work is complete.

The author argues that the naturally rash behavior of teenagers has amplified repercussions due to the prevalence of technology. She highlights the potential legal consequences by citing the example of 18-year-old Jacob Cox-Brown. In 2013, Cox-Brown revealed on Facebook that he had hit another car while drunk driving. The police saw the post and consequently arrested him. Similarly, an 18-year-old posted that she had been arrested for hitting another car while drunk driving, adding the abbreviation LOL (“Laugh Out Loud”). Due to the flippancy of her tone, a judge sentenced the teenager to 48 hours in prison.

Jensen also argues that technology can escalate teenagers’ poor choices by advertising them to a wider audience. The author recounts the experience of a colleague’s 16-year-old daughter, who was photographed asleep in class. When the picture was posted on social media, the girl who took the photograph was suspended and planned a revenge attack. Advertising her intentions on Twitter, the suspended girl invited others to come and watch. Jensen describes how a small crowd gathered and was arrested after watching her colleague’s daughter being assaulted.

Further technological dangers to adolescents are cyberbullying and invasions of privacy. Jensen cites the case of 18-year-old Jessica Logan, who hanged herself in 2008 after a former boyfriend sent nude photographs of her to classmates. The author also offers the example of Tyler Clementi, an 18-year-old student who came out as gay in 2010. A college roommate and his friends spied on Clementi kissing another male student via a webcam. Two days later, Clementi took his own life by jumping off the George Washington Bridge. The roommate and another student were charged with invasion of privacy.

Jensen advises parents to talk to their teenagers about the temptations of technology. She recommends moving computers to a common area and installing software to block inappropriate content.