Dr. Daniel Freeman, professor of clinical psychology at Oxford, has good news if you believe women are more nuts than men: there is a 40% chance you are right.

We know that discussing biological differences between men and women is taboo - men and women are no different in any physical way, as former Harvard President Larry Summers will rush to agree these days. But what about in psychological ways?  

Unlike Ivy League presidents, a professor has tenure and can't be chased out of his job by an angry mob of progressives, so Freeman wrote a book, “The Stressed Sex: Uncovering the Truth about Men, Women and Mental Health," analyzing the gender differences in psychological disorders based on 12 large-scale epidemiological studies during the last 20 years. He found the differences were substantial and the manifestations too, though it is unclear if the manifestations are biological or cultural.

“There is a pattern within – women tend to suffer more from what we call ‘internal’ problems like depression or sleep problems,” Freeman told James Ball of The Guardian. “They take out problems on themselves, as it were, where men have externalising problems, where they take things out on their environment, such as alcohol and anger problems.”

Which is why he found men were more like to have substance abuse issues. It may not be any biology at all, of course. If my wife says, "Sometimes you make me feel insane", that's environment, not anything to do with her gender. But, really, can her life be all that stressful compared to a peasant in Siberia?

Freeman found that women are nearly 75 percent more likely to have suffered from depression and are about 60 percent more likely to report an anxiety disorder. That's a big difference.  Not everyone is buying it. In his Guardian piece, Ball quotes Kathryn Abel, Professor of Psychiatry at the University of Manchester, who says there may be some cherry-picking of studies going on (whaaaaa?  In psychology???) in order to match Freeman's hypothesis. More interesting was her idea that our low-stress environment may be causing more mental health issues.

"In terms of survival, we're not exposed to stress compared with our ancestors," she said. "It is estimated that over their lifetime nearly a quarter of women will suffer a depressive illness. As a population, we are incredibly healthy, and in spite of continuing inequalities, we have never had it so good: women are living longer and more healthily than ever before – as are men.

"Some populations show lower rates of some of these arguably 'stress-related' disorders; in those countries women and men remain under far more hardship."

The good news is that DSM-5 is likely to close that gender, health and income gap in mental disorders. It will successfully find a pathology for everyone you meet.