Mental health advocate Matt Haig shares handwritten thank you note from Meghan Markle on Instagram

The duchess featured one of the author's quotes in her guest-edited issue of British Vogue

Mental health advocate Matt Haig has shared a thank you note he received from the Duchess of Sussex on Instagram.

Earlier this month, Meghan Markle included one of her “personal favourite” odes to body positivity, written by best-selling author Haig, in the September issue of British Vogue, which she guest-edited.

The piece is called “A Note From the Beach” and was taken from the author's book Notes on a Nervous Planet.

On Sunday, the 44-year-old author posted a photograph of a handwritten note he received from the duchess, in which she praised Haig for being a “force for change”.

The card, imprinted with a monogram of the duchess' initial with a crown, said: “Dear Matt, since reading 'Notes on a Nervous Planet' last fall, it instantly became a household favourite.

“When I knew I would be guest editing the September issue of British Vogue I knew you had to be a part of it.

“Thank you for being a force for change. The world needs more of you!”

In the caption of the photograph, Haig explained how he discovered the envelope from Kensington Palace among his usual post of bills and magazines.

The author, who has chronicled his experience with anxiety and depression, went on to explain how he wished he could tell his “young hopeless suicidal self about all of this magic to stay alive for”.

Haig concluded the post by joking that he has enrolled in handwriting classes, referencing Markle’s flawless penmanship.

Five years prior to her big break on TV series Suits, Markle supported her budding acting career by working as a calligrapher at Paper Source, a small shop for decorative papers and custom stationery, in Beverly Hills.

During her time at the company, Markle advised customers on projects like invitations for special occasions and taught a two-hour long class on calligraphy.

Last week, Haig commented on Instagram about Markle including his piece in British Vogue.

“She calls it her ‘favourite poem.’ A surreal honour. Glad she digs my stupid humour,” he wrote.

Body positivity is a topic that the duchess has touched on in the past.

In October 2018, Markle discussed the impact of airbrushing and photo editing while visiting Live for Tomorrow, an online youth programme, at the Maranui Cafe in Wellington, New Zealand.

(AFP/Getty Images (AFP/Getty Images)

“You see photos on social media and you don't know whether she's born with it or maybe it's a filter,” she said at the time.

“Your judgement of your sense of self-worth becomes really skewed when it’s all based on likes.”