An infectious agent, also known as a pathogen, is a biological entity that causes disease or illness to its host. These agents include bacteria, viruses, fungi, protozoa, and prions, each with unique mechanisms of transmission and infection.
Attention Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder characterized by symptoms of inattention, hyperactivity, and impulsivity that interfere with functioning or development. It is commonly diagnosed in childhood, but can persist into adulthood, impacting various aspects of life such as education, work, and relationships.