I'm not a doctor, or a vet, but I do see enough mental disabilities in my occupation to wager a decent hypothesis of the mental heath status of my lab. The verdict? I believe he has a touch of Obsessive Compulsiveness, or what we would call Obsessive Compulsive Tendencies in human psychology. Patients with OCD have rituals and routines, or compulsions that they feel they must do or their anxiety climbs, which is only relieved by performing said compulsion or intensive therapy and usually an extensive medication regime.
Duke, like his human equivalencies, has certain routines and objects of obsession. As I lay snuggled next to him this morning I realized that he only does this with me in the morning, and only after he has eaten breakfast. Furthermore he will only jump on the bed if I pull back the comforter, and at no point does it touch him. This got me thinking about his other compulsions . He must lay by the bathtub, but only if someone is either bathing or showering. He has an oral obsession, he must have something in his mouth when people come to the door. By default this was usually a shoe, but after several late mornings searching for a matching set I make it a point to clear the doorway. If there is nothing present he will grab an arm, leg, or other accessible body part, which obviously doesn't feel good and has led me to create a "go get a toy" command. Now he frantically surveys the house for something to grab, which has known to be a pot or dinner plate from the mornings naughtiness.
In addition to the routines, Duke has obsessions. Light reflections come to mind, but at a more intense obsession is water. He actually does what I've come to discover via google as "water freaking"
A common problem is "water-freaking," that is, once some find they can swim, they will get in any water they can find and swim around and around, often splashing, snapping at the splash, and yipping with excitement. Until they have a strong training foundation, they will not leave the water merely because you call them. If you have a water-freak, avoid water until obedience is well-established, and preferably force-breaking, too. The idea is to avoid reinforcing their enjoyment of playing in the water (so they don't develop a lifelong preference for water-freaking over retrieving).
I guess I have to be thankful that Duke is OCD and not ADHD which seems to be a common disability of labrador retrievers in this area. Duke is actually the easiest dog I have to train formal obedience. Which isn't actually an amazing feat, considering the level of obedience my other two have. And it's probably due, in part, to his OCD, but if I have to deal with it's negative aspects, I'm going to use its positive ones. I was once told by a respected psychologist friend of mine that most successful people have Obsessive Compulsive Tendencies and it's how you use them that equates failure versus success. Too bad Duke couldn't have sessions on the couch.
As a side note, as I sit on at the island in my kitchen typing this, the is sun shining through the window I can see little foot prints on the ceramic stovetop. But the terrier's diagnosis is another post entirely.