The document discusses what causes anxiety disorders like Generalized Anxiety Disorder (GAD). GAD affects around 7 million people and is characterized by excessive anxiety for at least 6 months that causes symptoms like sleep issues, irritability, and muscle tension. While the specific causes are not fully understood, factors that may contribute include genetics as GAD runs in families, environmental trauma, and imbalances in neurotransmitters like GABA, serotonin, and dopamine in the brain. Certain brain regions like the amygdala have also been linked to anxiety disorders and related physical health issues. Phobias are another type of anxiety disorder that some evidence suggests may be imprinted genetically.