I'm aware that many sociologists blast psychology for being too focused on the individual and I know in psychology I've criticized sociologists for only understanding issues without acting to help solve them. But I couldn't imagine any psychologist administering therapy without having some background knowledge in sociology and I couldn't imagine any sociology microtheorist attempting to understand human behavior without a little background knowledge in psychology. I couldn't believe my school didn't require sociology in my psychology degree. Of course, i've taken it any way and halfway through the class I realized how many mental "disorders" were more of a product of social constructions than of a brain disease or "chemical imbalance".
The most obvious example would be eating disorders, but I think it's pretty much accepted by most people that eating disorders are a product of a thin obsessed culture and media. But because social constructions, like gender and race for example, set the standards for cultures, anyone who does not fit those standards--such as people who don't wish to have a relationship with anyone, or who don't wish to participate in society, much like schizoid personality disorder is defined--are labeled to be weird or "disordered". I believe much of mental illness to be a social construction as well since the meaning of the symptoms and what's considered a symptom changes over time and place, between country and country, between doctor and doctor. Those of us suffering from these illnesses are made to know we are not the same as everyone else with labels and discrimination rather than the focus being on how to help.
Of course you can argue there are biological differences that do cause some illnesses, but even then it's also fact that we can't tell whether the "disorder" causes the "chemical imbalances" or whether the "chemical imbalances" causes the "disorders".