Open conversations about mental health are as important as ever — and social media influencers can play a key role in starting them.
Sometimes, however, the line between raising awareness and marketing can get blurred.
"When you are depressed, everything can often seem black and white. Meanwhile, color is much nicer … But how can you add color to your miserable thoughts?" German influencer Cathy Hummels captioned now-deleted pictures of her wearing sparkling sunglasses on Instagram.
"One factor that can help is light. Sun. Let's shine. 'Sun 'n' Soul Retreat' by @eventsbych," Hummels said in the post, shared earlier this month.
The post linked to another of Hummels' accounts called Events by CH — where the "Sun 'n' Soul Retreat" was promoted with videos showing a group of influencers doing sunrise yoga, poolside pilates, and painting on a Greek beach, whilst staying in a luxury villa and posting ad content throughout.
Posts with quotes like, "Turn your face to the sun and the shadows fall behind you," preceded content from the trip, interspersed with others highlighting advertising partners.
Those included sleepwear, beauty and hair, tea and jewelry brands as well as a chain of bookshops, which were frequently tagged in content posted during the trip.,
Their logos also featured as the backdrop for a video in which, one by one, those on the trip stood in front of the camera, making gestures like hugging themselves, pretending to drink out of a bottle or covering their head with their hands. Depending on the person and gesture in the video, corresponding writing appears.
"I suffered from anxiety," "I suffered from alcohol addiction," "I suffered from mental health," were some examples. At the end, everyone is in shot together. "STOP IT! Love yourself," the text reads.
The trip caused outrage among Instagram users and beyond. German mental health charity Deutsche Depressionsliga, which is run by and for those who have depression, released a statement titled "depression is not a marketing tool" in response.
"It becomes difficult when some social media accounts and appearances from bloggers create the impression that depression is merely a short-term occurrence and can be magicked away through sunrays for example," the charity said.
"It becomes very tricky when it is clearly used as an advertising tool to promote [own] products. In that case, so-called 'influencers' move on a fine and dangerous line," it added.
Hummels' management did not immediately respond to CNBC request for comment. She shared an apology via Instagram on Nov. 13.
Hummels said she experienced depression as a teenager and was seeking to raise awareness and show that mental health issues can impact anyone, including celebrities.
"Looking back, it is clear to me that I did not always achieve this in my communications. If people, especially those with depression or other mental illnesses, did not feel as if I took them seriously or were hurt by this, I am sorry and I apologize," she wrote.
Content from the retreat, including a video clip of Hummels sitting on a rock in an evening gown that includes "#strongmindstrongbody" and "#strongbodystrongmind" in the caption, is still visible on her Instagram account.
Simon Gunning, CEO at the British mental health charity Campaign Against Living Miserably, said that acting responsibly is most important when it comes to online conversations about mental health.
"The internet is awash with pseudo-science, and whilst there is a section of people who's livelihoods are dependent on an unforgiving set of metrics — followers and likes, engagement and reach — we should all be bound by a duty of care," Gunning told CNBC's Make It.
The World Health Organization, citing data from the Institute for Health Metrics and Evaluation, estimated last year that roughly 280 million people around the globe have depression.
The U.N. health agency says depression is different from typical mood fluctuations and short-lived emotional responses to challenges in everyday life. Indeed, it can develop into a serious health condition, "especially when recurrent and with moderate or severe intensity," and people can suffer greatly as a result.
The WHO says that, at its worst, depression can lead to suicide. It is thought that more than 700,000 people die due to suicide each year, with suicide known to be the fourth leading cause of death in 15 to 29-year-olds.
Gunning said talking openly about topics like mental health was a paramount issue.
"Celebrities and Influencers have an important role to play in raising awareness and opening up the conversation around mental health and suicide," he said.
This sentiment is echoed by the Deutsche Depressionsliga, whose statement points out that these conversations often help raise awareness.
When raising these issues online, the charity said there are a few things to keep in mind.
"Don't portray this life threatening illness as something casual and easy or a temporary mood! Please choose your words carefully!" Deutsche Depressionsliga said. It added that people should always signpost ways for those with depression to get help and explain that the illness often requires therapy.
Making sure content is evidence-based is also key, according to Dr. David Crepaz-Keay from the U.K.-based Mental Health Foundation.
"As someone that is initiating or offering those conversations, it's really helpful to concentrate on things that have an evidence base, to share references and additional resources with people from trustable sources," he told CNBC's Make It.
This might include research from medical professionals or official health organizations, he says.
As a consumer, it's equally as important to make sure information you see online is from a reliable source, Crepaz-Keay explains.
"Take these things seriously and slowly and particularly before you act on any anything that looks like clinical advice, check it from more than one source," he said, adding that sense-checking this with people you trust is important.