Justin Bieber is ''healthier than he's ever been'' since treating his Lyme disease symptoms.

The 'Yummy' hitmaker is battling with the disease - which is spread by ticks - and after his struggle with depression and anxiety as a result of Lyme was originally wrongly diagnosed as bipolar disorder, the correct diagnosis has helped him get on the path back to good health.

In his new documentary series 'Justin Bieber: Seasons' - which airs on YouTube Premium - his doctor Erica Lehman said: ''Lyme disease is the fastest growing bacterial infection in the United States right now. It can cause a whole spectrum of neuropsychiatric symptoms - mood swings, irritability, depression, anxiety. Justin fits the picture of these symptoms.''

In addition to Lyme disease, the singer also has been diagnosed with Epstein-Barr (EBV), which is commonly known as mono.

And now that he's taking the correct medication for his conditions, his wife Hailey Bieber has said the 25-year-old musician is ''on the road to maintaining a healthier life'' than ever before.

She said: ''Now that we have all the answers and know how to alleviate it and fix it. I think he's honestly not only healthier than he's ever been, but he's on the road to maintaining a healthier life than he ever has.''

Justin says getting out of bed in the morning can still be a struggle for him at times, but is committed to getting better because he doesn't want to throw away his ''opportunity to make a change''.

He told cameras: ''I know a lot of people feel the same way. So, I just also want to say you're not alone in that. Life is worth living. If you're not going to give up, the only thing to do is push forward. That's it.

''There are so many people who have gifts or an opportunity to make a change. And they end up losing it or using their gifts for selfish reasons. I see so many talented people and it feels like they're wasting something so precious. It's up to us as individuals to use the gifts that we've been given to contribute.''