Fear of darkness is called nyctophobia. It is an extreme fear of night or darkness that can cause intense symptoms of anxiety and depression. It's also called achluophobia, or lygophobia or myctophobia or scotophobia. While being afraid of the dark may be a part of normal development in young children, that is not the case for older children and adults. Nyctophobia is an age-inappropriate fear of darkness that can prompt someone to limit their activities, avoid certain situations, and experience anxiety in anticipation of there being no light. (A fear becomes a phobia when it’s excessive, irrational, or impacts a person's day-to-day life)