If you read the above paragraph and you agree with every sentence there, then please let me warn you: what follows is not going to be what people want to hear. You may not like what I have to say.
First, I don't agree that medical illnesses don't have stigma attached to them. I suppose it depends on what exactly "stigma" means to you -- oh, what exactly does "stigma" mean?-- but I would contend that if you have hypertension and you're not overweight, you eat a low salt diet, and you exercise regularly, then there's no stigma involved. If you have any medical problem associated with being overweight, poor dietary habits, smoking, alcohol, drug use, or lack of exercise, then others will look upon your illnesses as being your fault. The truth is that in our society, poor self control is stigmatized, and obesity in particular, is very stigmatized. Fat people are the last people (even after the mentally ill) that it's okay to openly discriminate against for everything from jobs to love. And many people think that's okay, because after all, many believe that obesity is the result of gluttony and laziness, or if not, then of poverty (oh, we stigmatize the poor as well) because they lack access to high quality food and athletic facilities. But if there's a way that society can blame you and your less-than-ideal behavior for your health problems, it will happen, and it's not all stigma-free.
One of the things we never discuss when talking about the need to reduce stigma is that psychiatric disorders sometimes lead people to behave in ways that are embarrassing or disturbing to others. People in the throes of an acute psychotic episode have been known to go outside naked, or to react in odd and alarming ways in response to things other people don't see, here, or understand. Sometimes ill people don't attend to their personal hygiene and they wear dirty clothes and smell badly. Other times, psychiatric disorders can cause people to be belligerent, to act in troubling impulsive ways, or to be unreliable and to miss work. Yes, cancer makes people unreliable and they miss work as well, but I would contend that an employer who has two equal job candidates in front of him might well choose the one who won't need to miss work regularly for any type of illness.
So how do we de-stigmatize psychiatric disorders when they are associated with disturbing behavior as a direct result of the illness? It seems it would be impossible, but I can think of one disorder where that seems not to be true: Attention Deficit Disorder comes with little stigma. I've often wondered why this is. ADD causes people to be inattentive, their lack of focus can be annoying, or disruptive in a classroom. They often had difficulties with executive functioning which means they forget things, are late, and come off as being scatterbrained (how's that for a scientific term?). They may forget they have appointments or forget to meet friends. In schools, they get more time for exams (does real life confer that as well?), and they may get all sorts of other accommodations such as front row seats or testing in quiet rooms. In addition, the treatment may include medications that have many side effects, including tics, agitation, insomnia, and addiction. In college, I hear this makes people fairly popular before exams -- it's not uncommon for those who have the diagnosis to share (or sell) their stimulants with those who just want to use them to study more intently, even though giving one's controlled substances to someone else constitutes a felony.
So here we have an illness that may make include symptoms that are often obvious, impair functioning, may infringe on the rights of others at times, include treatment with an addictive and dangerous medication, and yet ADD is not stigmatized. Why isn't that the case for bipolar disorder or schizophrenia? This issue of stigma is all very perplexing.
I welcome your thoughts here.