Sendak’s work has addressed problems as monumental for children as being in a rage at mother, relating to a depressed or emotionally unavailable mother, or coming to terms with a mother who cannot or will not recognise her child’s concerns or state of mind. He manages nonetheless to maintain the optimistic view that all of these troubles can be tamed, even if not fully overcome, through imagination. The ultimate magic of his work resides in his presentations of imagination, dream, fantasy and – ultimately – art itself as sources of resilience, of the strength to soldier on.
Sendak’s work .. is of particular interest to psychologists due to his strikingly unusual abilities to gain access to… fantasies that accompany childish rage states. It is this capacity, I believe, that contributes to the appeal of his work to children who are unable or unwilling to articulate these states, and to adults who have forgotten them or do not wish to know about them.
Source: here