In the last decade, rates of anxiety-related disorders in teenagers have steadily risen, particularly in girls. Researchers and psychologists posit several hypotheses about why these rates are on the rise — from digital hyperconnectivity to heightened external pressures to simply a greater awareness, and therefore diagnosis, of mental health concerns.

Whatever the causes, Dr. Lisa Damour has hopeful news for parents and teens: first, some degree of stress and anxiety is not only normal but essential for human growth. And if those levels become untenable, there are tested strategies for reining anxiety back in.

Reframing Anxiety

Damour, a psychologist and author of the new book “Under Pressure: Confronting the Epidemic of Stress and Anxiety in Girls,” has spent decades working with adolescent girls and their families. In recent years, she has noticed a change in how society views stress. “Somehow a misunderstanding has grown up about stress and anxiety where our culture now sees both as pathological,” said Damour. “The upshot of that is that we have adults and young people who are stressed about being stressed and anxious about being anxious.”

Anxiety is a normal and healthy function, according to Damour, and much of the anxiety that teenagers express is a sign that they are aware of their surroundings, mindful of their growing responsibilities, and frightened of things that are, in fact, scary. Adults can make a difference simply by “reassuring them that, a great deal of time, stress is just operating as a friend and ally to them.

Change and stress go hand in hand — even if a change is positive. Teenagers’ lives are filled with change: Their bodies and brains are transforming, they usually switch schools at least once between grades 5 and 12, their academic workload is increasing, and social relationships are constantly evolving. The anxiety that comes with stretching to face these and other challenges is part of how humans develop strength, said Damour.

When she talks with teenage girls, she uses the metaphor of exercise: To develop physical strength, you have to slowly push your levels of physical endurance, building up strength through resistance training. Similarly, said Damour, “you should see [a challenge] as an extraordinary weight training program for your mind. You are going to walk out of it tougher and stronger than you have ever been.”

Stress, Emotion and the Teenage Brain

Sometimes anxiety and stress reach levels that impede a girl’s ability…