In February of 1820, on learning that his good friend, Lady Georgiana Morpeth, was suffering from a bout of depression, noted essayist and clergyman Sydney Smith sent her the following precious letter, in which he listed twenty pieces of advice to help her overcome "low spirits."
Two similarly helpful letters of advice—specifically on the subject of depression—spring to mind when reading this: one from Stephen Fry; the other, from Henry James. All three are wonderful. For more information about depression itself, the Mind website is a good place to start.
(Source: The Selected Writings of Sydney Smith; Image of Sydney Smith: Replica by Henry Perronet Briggs, oil on canvas, 1840 (1833) NPG 1475 © National Portrait Gallery, London.)
Foston, Feb. 16th, 1820
Dear Lady Georgiana,
Nobody has suffered more from low spirits than I have done—so I feel for you.
1st. Live as well as you dare.
2nd. Go into the shower-bath with a small quantity of water at a temperature low enough to give you a slight sensation of cold, 75° or 80°.
3rd. Amusing books.
4th. Short views of human life—not further than dinner or tea.
5th. Be as busy as you can.
6th. See as much as you can of those friends who respect and like you.
7th. And of those acquaintances who amuse you.
8th. Make no secret of low spirits to your friends, but talk of them freely—they are always worse for dignified concealment.
9th. Attend to the effects tea and coffee produce upon you.
10th. Compare your lot with that of other people.
11th. Don't expect too much from human life—a sorry business at the best.
12th. Avoid poetry, dramatic representations (except comedy), music, serious novels, melancholy sentimental people, and every thing likely to excite feeling or emotion not ending in active benevolence.
13th. Do good, and endeavour to please everybody of every degree.
14th. Be as much as you can in the open air without fatigue.
15th. Make the room where you commonly sit, gay and pleasant.
16th. Struggle by little and little against idleness.
17th. Don't be too severe upon yourself, or underrate yourself, but do yourself justice.
18th. Keep good blazing fires.
19th. Be firm and constant in the exercise of rational religion.
20th. Believe me, dear Georgiana, your devoted servant, Sydney Smith