Solange Knowles has said she ''shut down'' when she was a teenager.

The 30-year-old singer - who is the younger sister of fellow musician Beyoncé - has penned a touching letter to her younger self for Teen Vogue magazine, in which she details the ''bleakest darkness'' she felt and urges herself to ask for help from her family and friends.

She wrote: ''You shut down. You go into your room, lock the door, put on music, and you do not move for eight hours straight. It will feel like the heaviest and bleakest darkness you can possibly feel, and when you ask everyone to leave you alone and let you be, what you really want to say is 'I want you here' and 'I need help.'

''Sometimes it is OK to say just that. It won't make you less strong or less powerful. No one you love will criticise you or blame you; in fact, they will lift you up.''

And the 'Cranes In The Sky' singer also spoke about the ''phases'' she went through growing up, and gave her younger self advice on how to deal with bullies.

She added: ''Sometimes you push these phases to the max, and when you go out into the world feeling confident in who you are and what you reflect, young folks will call you names and grown folks will call you names. It's OK. One day you will name yourself, and that name will belong to you. It will not be the ones they ordained: 'Crazy, ugly, attention-seeking, weirdo.'''

Solange adds that she occasionally still finds herself the subject of name calling as an adult, but has learned to turn them ''into a symbol of beauty''.

She wrote in the letter for Teen Vogue magazine, which was published on Wednesday (17.05.17): ''I really hate to tell you this, but sometimes you will still get called these things as an adult, except you will actually embrace some of them. You will learn that these are just words. Words that only have power if you choose to give them power. Every once in a while they will hurt, but you will choose to turn those words into a symbol of beauty.''