Figure 3.

Gender bias in neurologic and neuropsychiatric disorders. A compelling reason for studying sex as a biological variable is the pervasive gender bias in the frequency of diagnosis of numerous disorders. Many factors go into the determination of a disease state, but identification of biological variables clarifies those influences that are not biological in origin (i.e. diagnosis bias, different symptomology, etc.). This diagram presents only a small number of the many diseases and disorders known to differ in frequency between boys and girls, men and women. The size of the wedge for each disorder represents the relative degree of bias in favour of females (left) versus males (right) and is loosely based on [75–87]. ADHD, attention deficit hyperactivity disorder; PTSD, post-traumatic stress disorder. (Online version in colour.)