This I don't agree with you on. There are definatly positive and negative states of the mind. Schizophrenea is never a positive condition, and neither is Bi Polar, and I think everyone with this type of condition should be couciled, and should seek help. These conditions are not normal, and definatly need a permant cure, and more public awareness.
I've known a few people with Bipolar disorder who have led very creative lives. It generally comes down to the environment that they get stuck in. In a modern, ordered society, a lot of this can come out as rage, which is why it's given such a bad rep. I agree in most situations (given a modern lifestyle), bipolar is a burden. I guess it's more of a "take it at face value" thing, given the person's living environment, etc.
I used to work in a Mental Health Center for Volunteer Work. I've also seen a few Bi Polar people live with their desease, but never without medication, and I wouldn't exactly call their lives creative. Most Bi Polar patients psycically harm others around them, and often have very unhealthy relationship with people near them because even when their family understand the disorder, when you see a loved one get angry at you and yell at you for almost no reason, it will hurt family ties. If there is a small creative positive here, it's not worth all the Negatives and life shattering conditions. No one should be encouraged to live with the disorder, and at a slight loss of creativity, everyone should be cured. No Bruises and Domestic Disturbances for Art.
As for Schizophrenic people, out of all the patients who came in, I only ever met 1 patient who wasn't a return patient, and I have not met a single schizophrenic person who was able to live with their illness. This type of condition really messes you up, I've seen people yell at God, call their families clones, wear boxing helmets to protect themselves from evil demons, and even see people communicate to dogs via telekenisis. This is not a condition to joke about, and definatly one which needs to be rid from out human population. It has NO positive.