Eating disorders are conditions defined by abnormal eating habits that may involve either insufficient or excessive food intake to the detriment of an individual's physical and mental health. Pooh is constantly looking for honey, and he goes completely out of his way to get it. Pooh could also be characterized as a substance abuser.
Piglet could be characterized as having general anxiety disorder. Generalized anxiety disorder (GAD) is an anxiety disorder that is characterized by excessive, uncontrollable and often irrational worry about everyday things that is disproportionate to the actual source of worry. Individuals often exhibit a variety of physical symptoms, including fatigue, fidgeting, muscle tension, muscle aches, difficulty concentrating, trembling, twitching, irritability, agitation, sweating, restlessness,and inability to fully control the anxiety. Piglet is consistently terrified of everything.

Tigger could be characterized as having ADHD. Attention deficit hyperactivity disorder is a psychiatric disorder or neurobehavioral disorder characterized by significant difficulties either of inattention and/or hyperactivity and impulsiveness. There are three subtypes of the disorder which consist of it being predominantly inattentive (ADHD-PI or ADHD-I), predominantly hyperactive-impulsive (ADHD-HI or ADHD-H), or the two combined (ADHD-C), which shows all three difficulties. Tigger has an inability to sit still, and is constantly bouncing around.

Obsessive–compulsive disorder (OCD) is an anxiety disorder characterized by intrusive thoughts that produce uneasiness, apprehension, fear, or worry; by repetitive behaviors aimed at reducing the associated anxiety; or by a combination of such obsessions and compulsions. Symptoms of the disorder include excessive washing or cleaning; repeated checking; and nervous rituals, such as opening and closing a door a certain number of times before entering or leaving a room. Rabbit is a complete and total neat freak. If things are done differently than he would have done them, its wrong.

Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behavior, feelings and sense of well-being. Depressed people may feel sad, anxious, empty, hopeless, worried, helpless, worthless, guilty, irritable, hurt, or restless. Eeyore is the poster-child (poster-animal?) for depression. You cannot tell me that you didn't make that connection when you were little. That Eeyore was always sad or miserable.
Narcissism is a term that originated with Narcissus in Greek mythology who fell in love with his own image reflected in a pool of water. Currently it is used to describe a person characterized by egotism, vanity, pride, or selfishness. Whenever Owl is asked a question he goes of on a tangent about himself or his relatives.
Schizophrenia is a mental disorder characterized by a breakdown of thought processes and by a deficit of typical emotional responses. Common symptoms include auditory hallucinations, paranoid or bizarre delusions, or disorganized speech and thinking, and it is accompanied by significant social or occupational dysfunction.
Christopher Robin, believes that all the previously stated animals can talk, and that they interact with their environment, with him, and with each other