Anxiety doesn’t discriminate and anxiety can happen in the adult years. It can strike all human beings, and anxiety can happen at any age. Humans progress through distinct developmental stages as they grow, and each stage is marked by specific tasks and characteristics. Sometimes, things go wrong at one or more stages of development. When a stage isn’t completed successfully, problems can occur (Anxiety Causes: What Causes Anxiety?). It is for this reason that anxiety can happen at any age — including in the adult years.