Jake Paul has been heavily criticised after telling Twitter followers to "remember anxiety is created by you".
His comments provoked a strong reaction online, where people suffering from anxiety condemned the "dangerous" advice.
Others sarcastically thanked him for his suggestions.
The YouTuber, who has close to 20 million subscribers on the video-sharing platform, subsequently deleted his tweet.
"Remember anxiety is created by you," Paul wrote.
"Sometimes you gotta let life play out and remind yourself to be happy and that the answers will come.
"Chill your mind out. Go for a walk. Talk to a friend."
The remarks triggered an immediate response. Thousands of social media users propelled Jake Paul, who has recently started selling subscriptions to a "financial freedom movement", into the top trending terms on Twitter.
all of us are gettin cured of our anxiety disorders from jake paul’s tweet tonight... honestly a revolutionary moment— taylor nicole dean (@taylorndean) February 18, 2020
Many shared experiences of their own mental health conditions being dismissed.
Natalie Tran, an Australian YouTuber who has spoken publicly about her own mental health struggles, recalled an incident in which her obsessive compulsive disorder (OCD) had been brushed off.
"I tried to talk to someone... about my OCD and he told me that he didn't want to listen because what had happened, according to him, was that the people in my life had spoiled me," she tweeted.
"That's what my OCD was."
telling people with anxiety to just stop having anxiety does not help them with their anxiety.— Colleen Ballinger🎗 (@ColleenB123) February 18, 2020
This was what made "flippant" comments about anxiety so damaging, mental health campaigner and writer Lucy Nichol, who herself has an anxiety disorder, told BBC News.
"Because we can relate some day-to-day things to mental health conditions like anxiety, it's quite easy to be dismissive," she said.
"I've had years and years of therapy. I've been taking anti-depressants. I've had to take beta blockers when it's been really bad.
"One of my worst ever panic attacks occurred when I woke up at 03:00. Within about 30 seconds, I had a very bad panic attack.
"I thought I was going to die. It took about one and a half to two hours. It doesn't help to be told to chill out."
"It's one of the stereotypes about anxiety that I detest.
"If someone experiences very severe anxiety and sees those sorts of comments, they might not seek help."
Symptoms of anxiety
Anxiety can cause many different symptoms. It might affect how you feel physically, mentally and how you behave.
And it is not always easy to recognise when anxiety is the reason you are feeling or acting differently.
According to Anxiety UK, anxiety is one of the most prevalent mental health conditions in the UK - one in five people will experience an anxiety condition.
"Everyone regularly experiences anxiety to some degree," a representative said.
"When anxiety symptoms become too strong, however, a normal, natural response can develop into an anxiety condition or disorder.
"It is important not to generalise about support as there are many different avenues of support when it comes to anxiety, from self-help techniques and peer support to more professional services that can be accessed both through your GP and privately."
In a later tweet, Paul said he had also suffered from anxiety and had been "spreading more awareness".
"Everyone [is] clowning my tweet," he wrote.
"I didn't even know [anxiety] was a thing until I was 18 but [I have] had it my whole life and never knew how to deal with it."
Jake Paul and his brother Logan Paul have both built huge online followings.