Lack of melatonin
Sleep is one of the most important factors when it comes to improving your productivity and concentration. The sleep hormone melatonin has a powerful effect. If there is a deficiency, it can lead to signs of anxiety, poor stress responses, insomnia, and waking up too early in the morning. Melatonin is a hormone that is produced on its own, but for various reasons (described below), its level may decrease. At the same time, you can control it, and contribute to an increase in its production in the body.