Having major a.k.a. clinical depression is having a disease. And like any other disease, such as cancer or diabetes, you cannot cure yourself with your mind by simply being optimistic and "strong". Treatment can take months and sometimes years, with very gradual improvements. There is usually no single cause to depression, and it is wrong, ignorant, hurtful, and unhelpful to ask people with depression "why are you depressed", act like you know what is causing their depression, or tell them to simply "be happy". It is necessary to accept that there is nothing you can do to help a person with depression other than maybe keep him company.
The Myth: Mental illnesses are all in your head, and you can just get over them if you really want to.
This earned the number one spot, not only because it’s general, but because it’s probably the most damaging myth about mental illness, since it prevents the acceptance of depression as a real disease. Some people still believe that mental illnesses are all imagined by their sufferers, or that people who suffer from mental illness can’t really be having that much trouble or just don’t care enough about getting over it. People are especially likely to be dismissive if they don't know much about the illness.
The fact that the same symptoms have been experienced by so many different people should prove that they are real — they can’t all be independently inventing the same symptoms. Any mental disorder, by definition, seriously affects the lives of the people who suffer from it, usually for the worse, or it would not be considered a disorder. And they are certainly not easy to get over. Most mental disorders are caused at least in part by a difference in the brain or an imbalance of chemicals. Even when it comes to the non-physical reasons, it’s very difficult to un-learn a thought pattern or habit — just choose any habit and try it. Plus, the disorder itself may stop someone from trying to get help: people with depression might think no therapist will be able to help them, and be too tired to try to find one, anyway. If we could overcome mental illnesses just by wanting to, the world would be full of much happier and more productive people.
The Just World Hypothesis
There is also the belief that if something bad happened to you than you deserve it. The need to see victims as the recipients of their just deserts can be explained by what psychologists call the Just World Hypothesis, a cognitive bias. According to the hypothesis, people have a strong desire or need to believe that the world is an orderly, predictable, and just place, where people get what they deserve. It's the belief that the wrong-doers will always be punished and good-doers will always be rewarded. This belief leads to the conclusion that victims of misfortune deserve what happens to them. So those with afflictions are seen as at fault, whereas none is due. You wouldn't blame a cancer patient for getting cancer, nor should you a depression patient. Sure, some of the cancer patient's life choices (bad diet, lack of exercise) contributed to him getting cancer, but we don't blame him for getting it. This belief also leads to other terrible conclusions, such as that rape victims and victims of child abuse are somehow responsible for their misfortune. There are other, more subtle beliefs that stem from the Just World Theory, such as that poor people are wicked and rich people are righteous. This idea comes from the Bible, which says that if you commit a sin, several generations will pay for it. It's also present in some eastern thought, as "karma", or everything bad that happens to you is punishment for something you did in your past life. Such a belief plays an important function in our lives since in order to plan our lives or achieve our goals we need to assume that our actions will have predictable consequences. Moreover, when we encounter evidence suggesting that the world is not just, we quickly act to restore justice by helping the victim or we persuade ourselves that no injustice has occurred. We either lend assistance or we decide that the rape victim must have asked for it, the homeless person is simply lazy, the fallen star must be an adulterer. These attitudes are continually reinforced in the ubiquitous fairy tales, fables, comic books, cop shows and other morality tales of our culture, in which good is always rewarded and evil punished.
The Fallacy of Control
This belief that you can always control how you feel probably stems from Americans' overly individualistic view of the world. We believe that we alone are responsible for our fortune and misfortune. This is actually very rarely true. In real life, there are many things (such as our emotions) that are out of our immediate control, and most of the time the perception of control is an illusion. This is especially true for people with depression, who cannot cure their depression with their minds anymore than a person with cancer can cure his cancer. Even thought the majority (80 percent) of people with depression eventually (in six months on average) recover (due to mostly unknown reasons), a minority (20 percent) has what is called treatment-resistant depression, which does not respond to treatment. If you are one of a few people who are unemployed in a nation, it's probably your responsibility, but if you are one among the 10% of the nation's unemployed, this isn't a personal problem anymore but a social problem. However, when we see an individual who is unemployed, we discount all the social forces that caused him to be unemployed and assume that he is just lazy or unwilling to find work.
The Mind-Body Separation
What I've noticed is that people are much more reluctant to accept the existence of mental illnesses then physical ones. This reluctance has the effect of preventing insurance parity (equal treatment) between physical and mental problems. One person I know is OK with taking fat burning pills that contain the supplement 5-HTP (an appetite suppressant and mood enhancer), but he is not OK with taking 5-HTP by itself.