There is a link between adult acne and stress and research has proven it. In fact, stress is considered one of the main culprits when it comes to acne in adults. Acne breakouts happen when your body is stressed because of the increase in stress hormones that can throw off your equilibrium. This can cause all sorts of changes, such as weight gain, increased blood pressure, and worsened acne. Experts are divided on whether stress actually creates acne or just worsens it.