Speaking in his YouTube Originals documentary Justin Bieber: Next Chapter, he added "I want to be the type of person and leader who can tell people, 'You don't have to put on a front.
"You don't have to act a certain way. Who you are is enough.' I feel so just at peace for the first time in my life ... I just would encourage people, like, 'Hey, if you're feeling lonely, talk about it. Say it out loud.'
"There's a freedom in that. I could have avoided a lot of pain."
After the documentary aired this week, Bieber took to social media to insist he was doing better now and has managed to "grow" a lot in the past eight months.
He told his followers: "The last eight months have been a time for growth. Happy and healthy."
Bieber revealed he has been using "prayer and meditation" to help him through quarantine.
Bieber said: "Prayer and meditation. What's helped me is that I work out a lot; stay physical and stay active.
"I pray and meditate, things like that. I write music, listen to music. Music is very powerful; it can really help you when you're feeling low."
WHERE TO GET HELP:
If you are worried about your or someone else's mental health, the best place to get help is your GP or local mental health provider. However, if you or someone else is in danger or endangering others, call police immediately on 111.
OR IF YOU NEED TO TALK TO SOMEONE ELSE:
• LIFELINE: 0800 543 354 (0800 LIFELINE) or free text 4357 (HELP) (available 24/7)
• SUICIDE CRISIS HELPLINE: 0508 828 865 (0508 TAUTOKO) (available 24/7)
• YOUTHLINE: 0800 376 633
• NEED TO TALK? Free call or text 1737 (available 24/7)
• KIDSLINE: 0800 543 754 (available 24/7)
• WHATSUP: 0800 942 8787 (1pm to 11pm)
• DEPRESSION HELPLINE: 0800 111 757 or TEXT 4202