What is Behavioral Health?

Human Diseases and Conditions

The Brain and Nervous System

If life is a symphony of activities—both voluntary activities, such as walking, talking, reading, or going to class, and involuntary activities, such as breathing, digesting food, pumping blood, and perspiring—then the nervous system is the orchestra that makes it all happen. This system controls all of the adjustments people need to make in response to their environment, from basic functions such as sweating on a hot day to more sophisticated tasks such as concentrating attention during a particularly difficult lecture.


Abuse is a form of violence in which one person harms another physically or emotionally. The abuser often uses an advantage of size, power, or influence to hurt or mistreat the target of the abuse, who may be smaller, younger, or weaker.


When friends first told Josh that his drinking and drug use were out of control, he ignored them. He liked to party, he said, but he could stop anytime he wanted.


In Greek, the word agoraphobia means "fear of the marketplace." In English, the term is used to describe a disabling disorder that often leads people to fear being in crowds, standing in lines, going to shopping malls, or riding in cars, buses, or subways. In its most extreme form, the disorder can make people afraid of traveling beyond their neighborhoods or even stepping outside their homes.


Jennifer had her first glass of champagne at a family wedding when she was 11. By the time she was 13, she was drinking beer with her friends on Saturday nights.

Alzheimer Disease

In 1907, the German physician Alois Alzheimer published an artide on what he called a "new disease of the [brain] cortex." Little did he know that it would be named after him! In that article, he described the increasingly bizarre behavior of a 51-year-old patient and went on to describe what he found upon examining her brain after death.


What would it be like to wake up one morning and not know who you are, not recognize your home or your parents, or not be able to account for your actions in the past days? This image of amnesia has been the basis of many movies and books.


Wendy has been taking ballet since she was 5. For as long as she can remember, her dream has been to dance professionally after she graduates from high school.

Antisocial Personality Disorder

Antisocial personality disorder (APD) is one of the ten different types of personality disorders* that are currently classified by mental health experts. Like other personality disorders, APD refers to a personality style that consists of troubled ways of thinking, feeling, and behaving, and it is diagnosed only in adults (but the personality style and the problematic behavior it causes must have been present since adolescence).

Anxiety and Anxiety Disorders

On the first day of ninth grade, when Michelle started high school, she suddenly felt dizzy, sweaty, and short of breath when she walked down the hall toward her locker. For a few minutes, everything around her seemed strangely unreal.

Asperger Disorder

When Brian turned two years old, his parents were thrilled with his large vocabulary, which surpassed that of any other two-year-old they knew. Because Brian seemed so bright, they tried to ignore the fact that he spoke in a monotone, rarely made eye contact with them, and never wanted to play with the other children in his playgroup.


Neuroscientists (nor-o-SY-in-tists), or scientists who study the brain and nervous system, believe that attention is largely a function of the brain's reticular activating (re-TIK-yoo-lur AK-ti-vay-ting) system, or RAS. This system includes a group of nerve fibers located in several parts of the brain, including the thalamus*, hypothalamus*, brain stem*, and cerebral cortex*.

Attention Deficit Hyperactivity Disorder

As a sixth-grader at a new middle school, Kevin was having a much harder time than he expected. Then again, school had never been easy for him.


People who are shy are not very talkative and often look down or away when someone else talks to them. They also seem to spend a lot of the time by themselves.

Bedwetting (Enuresis)

Enuresis (en-yoo-REE-sis) is the involuntary, unwanted release of urine either in the day or at night in people who are old enough (around ages 5 to 6) to have gained bladder* control. Bedwetting is a specific kind of enuresis that occurs at night during sleep.

Binge Eating Disorder

Rebecca's parents sometimes got into fights that literally scared her out of the house. She often ended up at her neighbor's house, where she was treated to hot chocolate, cookies, and other goodies.

Bipolar Disorder

Bipolar disorder is a type of depressive disorder*. People with bipolar disorder experience two (thus the prefix "bi") extremes in mood; they have periods of extreme happiness and boundless energy that are followed by periods of depression.

Birth Defects and Brain Development

Starting at conception, the developing embryo* is susceptible to many factors that affect development. During the first twelve weeks of development, the cells of the embryo and fetus are rapidly dividing and becoming the infant's muscles, bones, and organs.

Body Dysmorphic Disorder

Most people pay attention to their appearance. They may check themselves in the mirror, think about which clothes look nice on them, and try to look their best.

Body Image

Brain Chemistry (Neurochemistry)

Now a tenth-grader, Hector had been experiencing severe depression since he was in seventh grade. Everyone feels down or depressed every now and then, but Hector felt this way most of the time.