GAD is one of the anxiety disorders found in the Diagnostic and Statistical Manual of Mental Disorders — the basis for psychiatric diagnosis, published by the American Psychiatric Association.

People with GAD worry about many things. Their worries are not attributable to another psychiatric disorder. For example:

- It is not just worrying about the next panic attack (Panic Disorder);

- It is not just worrying about being humiliated in public (Social Phobia);

- It is not just worry about contamination or other obsessive fears (Obsessive Compulsive Disorder);

- It is not just worry about being away from home or a close family member (Separation Anxiety);

- It is not just worry about gaining weight (Anorexia Nervosa);

- It is not just worry about having certain diseases or illnesses (Hypochondriasis), etc.