As children grow and develop, they move through a range of behaviors at each developmental stage. Most two-year-olds share certain behaviors that are considered normal for their age group. On the other hand, a twelve-year-old who displays these same behaviors would be suspected of having a behavioral or emotional problem. Generally, when a child or teen shows behaviors that are not considered normal for his or her age, this will draw the attention of parents, teachers or others who have contact with them.

Abnormal or unusual behavior falls into four categories:

1. Acting Out behavior – Acting out behavior includes being disruptive; aggressiveness or violence toward others; cruelty to animals or other children; self-abuse.
   
   
2. Withdrawing behavior – This is much more than shyness and should show a strong signal if a child who once was outgoing become very withdrawn. Withdrawn behavior includes depression, refusing to talk or have social contact with others, regressing to babyhood.
   
   
3. Anti-social Behavior includes lying, cheating, manipulating others, or breaking the law.
   
   
4. Disorganized Behavior includes being out of touch with reality, seeing or hearing things that aren’t real, or paranoia.

Abnormal or unusual behavior spans a range from mild to severe, as do children’s disorders themselves. One child’s behavior can be a temporary response to a crisis in his or her life, with few negative consequences. Yet another child will need long-term supports and treatment. Each child is individual.

Children’s disorders fall into several categories: behavioral disorders, mood disorders, anxiety disorders, psychotic disorders, developmental disorders and others that don’t fall neatly within a special category. Each diagnosis has a preferred type of treatment or "best practice," so it is important to get the right diagnosis. Because the origin of children’s disorders is so complex, your child’s mental health diagnosis may change over the course of his treatment and some children won’t fall neatly into one diagnostic category.