In my High School Psychology class we were given a project in which we had to analyze the characters of A. A. Milne's classic story of Winnie the Pooh.  I was rather anxious to do this, since I grew up around an Aunt and Uncle who are obsessed with the Red Shirt wearing yellow Bear.  Here is a quick analysis since I do not have access at this time of the actual paper that I wrote yeas ago.

Eeyore - A manic depressive being.  He is also misplacing the things that are most important to him, and he has an issue with owning a permanent residence. 

Owl - While extremely intelligent, he seems to suffer from some sort of neurodevelopment issue.  Perhaps Dyslexia since he is usually depicted reading, however the books are usually turned upside down.  He seems to mix up his knowledge quite often, however he honestly believes what he says is fact.

Kanga - The over protective single mother.  She is mainly focused on the well-being of her son, rather than attempting to have a life of her own. 

Roo - The child of a single mother.  He spends his life longing for a father figure.  Which he usually spends his time with Rabbit for insight, but spends most of his time with the trouble maker that is Tigger.  He is a rather confused individual, not knowing what paths he should take, due to the lack of a proper father figure, which could then lead to a sever personality disorder.

Piglet - A rather anxious and worrisome being... and paranoid.  His paranoia eventually has led to visual hallucinations and the belief in an unseen being (Heffalumps).

Rabbit - A very social being, but rather obsessive (his tidy place and his collections)

Tigger - While egotistical and proud, he is a sever risk taker, and does not ponder his consequences before he makes a decision.  He always must be the center of attention, and is overly hyper during social situations.

Winnie the Pooh - He seems to suffer from a neurological issue,  as well as a compulsive obsession when it comes to honey.  He fixates on the idea of nothing other than obtaining honey, which does not allow him to focus on anything else, which could wrongly diagnose him as ADD.

Christopher Robin - By far the most sever case in the story.  It is not clear on his true mental state, but schizophrenia is a sever possibility.  The lack of parental supervision is unhealthy and has led him to fantasize and personify both stuffed animals and real animals (owl and rabbit) alike.  It's interesting to note that Christopher Robin is the actual son of A. A. Milne and that the stuffed animals were his real toys as a child, and to his death he despised his father and immortality he was given from the stories.