The main element from the true story in 'The Babadook' is the psychological state of the characters. In real - life, people who are going through tough times, like dealing with the death of a family member or a major life change, can experience a range of complex emotions. In the movie, these emotions are personified through the Babadook. For example, the Babadook's constant presence and its ability to make the characters feel scared and out of control could be related to how in real life, our own negative emotions can seem to take over. Also, the mother - son relationship in the movie is affected by this 'presence', which could be based on how real - life emotional turmoil can impact family relationships.
One element could be the sense of overwhelming grief. In the movie, the main character's struggle with the Babadook might be related to the real - life struggle with the intense emotions that come after a loss. Another element could be the feeling of isolation, which often accompanies such difficult emotional states in real life.