The IRS claims in a pretrial motion that gender reassignment surgery isn't tax-deductible, and says that just because gender dysphoria appears in the DSM-IV, that doesn't make it an illness—after all, "Other so-called disorders in the DSM appear not to have any component of illness, mental or otherwise, such as 'Circadian Rhythm Sleep Disorder, Jet Lag Type,' i.e., jet lag." [Tax Prof]