[QUOTE=Mort Hog]What did the director's commentary say?[/QUOTE]
"Writer/director Richard Kelly does not deny personal interpretations, but has expressed his own theories through the extra commentary on the two DVDs, his own (fictional) book The Philosophy of Time Travel, and in various other interviews.
According to Kelly and his Philosophy of Time Travel, at midnight on October 2 a Tangent Universe branches off the Primary Universe around the time when Donnie is called out of his bedroom by Frank, immediately before the appearance of the Artifact, the faulty jet engine. The inherently unstable Tangent Universe will collapse in just over 28 days and take the Primary Universe with it if not corrected. Closing the Tangent Universe is the duty of the Living Receiver, Donnie, who wields certain supernatural powers to help him in the task.
Those who have died/will die within the Tangent Universe (and would not have died otherwise) are the Manipulated Dead (Frank and Gretchen Ross). Manipulated Dead Frank, at least, is also given certain powers in that he is able to subtly understand what is happening and have the ability to contact and influence the Living Receiver via the Fourth Dimensional Construct (water). All others within the orbit of the Living Receiver are the Manipulated Living (e.g. Ms. Pomeroy, Dr. Monnitoff), subconsciously drawn to push him towards his destiny to close the Tangent Universe and, according to the Philosophy of Time Travel, die by the Artifact.
There are two "Franks" in the story: the living boyfriend of Donnie's sister Elizabeth, and the Manipulated Dead Frank who appears to Donnie as a premonition from the future in the disturbing rabbit suit (the second Frank is dead, or undead; at the end of the film he is killed by Donnie). Dead Frank is aware of Donnie's fate and destiny."
I think my use is obvious.
The coddling child-state. The feminization of the 'healing process' actually impedes success: the narrator, for instance, becomes addicted to this coddling because it's easier than resolving his actual issues. It isn't until he becomes subconsciously sexually attracted to Marla that the child-state loses its appeal.
The feminization of the characters was a really important part of the book. For instance, the narrator never had a father figure in his life, so when he is ready to man it up he creates one. All quite Freudian, really. You could view the ending as fourth and fifth stages: senility and patriarch-worship/godhood.