Joseph Wright of Derby and Dr Erasmus Darwin, the artist and his physician.

In 1767 at the time of his great "candlelight" paintings of science and the Enlightenment, and , Wright of Derby developed the illness that plagued him for the rest of his life and became a patient and life-long friend of Dr Erasmus Darwin. Wright's recorded complaints and the periodicity are highly suggestive of the major depressive illness, seasonal affective disorder.