ABA therapy is used to treat autism by helping children develop skills and avoid problematic behaviors. Autism is a mental illness diagnosed in childhood where symptoms like slowed development and reluctance to socialize emerge. It occurs from birth to age 3 and can impact language, social, and thinking skills. While the exact causes are unknown, genetic factors and issues during pregnancy may play a role. Early signs include lack of eye contact, response to sounds or voices, and delays in smiling or speaking. Precautions include a healthy lifestyle and diet during pregnancy to potentially reduce risks.