People who rely on alarm clocks to wake up and caffeine to stay awake during the day tend to over-emphasize both Beta and Delta wave states. The alarm awakens them from deep sleep leaving them drowsy and needing the pick-me-up of caffeine, which encourages Beta wave states, which are part of a cycle of reinforcement--the stress of time pressure during the day plus the caffeine both promoting Beta waves. At night, exhaustion from daily stress and poor sleep in previous nights sends them into deep sleep quickly, where growth hormone release can be triggered, helping to heal the body from the day's stress. However, this pattern minimizes or avoids both Alpha and Theta states, with their relaxation, immune function support, and stress reduction capacity. Research on chronic fatigue has shown that its effects may be caused by the inability of the brain to attain or maintain certain Delta waves state frequencies sufficiently, but when assisted to attain them, symptoms of chronic fatigue improved.

Even though it is the state least like waking, Delta wave states, that is, in sleep stages 3 and 4, are when most sleepwalking and sleeptalking occur.

In people with Attention Deficit Disorder (ADD), attempts to focus, which would normally decrease Delta activity, actually increase Delta activity, making focus more difficult, and locking the brain into an unfocused and drowsy state. In healthy, awake adults, Delta feels like a trance, if there is any awareness of it at all, as it is usually associated with sleep or unconsciousness, such as in a coma.