In the research to explain whether anorexia nervosa is caused by psychological factors several explanations were given. The ?Psychodynamic explanation? being one of the main ones suggests that ?one? is motivated to behave the way they do by unconscious and often repressed desires that featured in their past. For example someone doesn?t want to grow up, set off in to adulthood, instead they want to remain a child; not eating helps them to do this as it ?preserves childhood?. What makes it easier for them to do this is the support from the mother. She wants to take care of a child and to feel needed; thus by having a frail and sick child keeps the mother/daughter relationship going. Another reason came from Freud who stated that eating is a substitute for sexual expression; one who doesn?t eat is avoiding their sexuality or repressing their sexual impulses.