The Royal Society for Public Health's (RSPH) survey called #StatusofMind found the photo-sharing app negatively impacted on people's body image, sleep and fear of missing out.
Helen Cutteridge, who leads on emotional wellbeing for the Christian charity Youthscape, told Premier's News hour that she wasn't surprised by the findings.
She said: "Instagram is this platform for young people to constantly compare themselves to each other.
"If you're waking up in the morning and you've got gross hair and gross breath and you're comparing yourself to an image that your friend has spent half an hour taking - putting on make-up and adding the right filter - you're comparing yourself to something that's unattainable and this happens for young people daily."
However, the survey of 1,479 youngsters aged 14 to 24, found Instagram was positive in terms of self-expression and self-identity.
Respondents were asked to score how each of the social media platforms they use impact upon issues such as anxiety, loneliness and community building.
The RSPH's report said: "The platforms that are supposed to help young people connect with each other may actually be fuelling a mental health crisis."
The site with the most positive rating was YouTube, followed by Twitter. Facebook and Snapchat came third and fourth respectively.
Recommendations from the report included social media platforms discreetly signposting help to those potentially suffering from mental health issues.
The survey also found that seven in 10 people questioned supported introducing pop-ups on sites such as Twitter and Facebook to warn users about heavy usage.
Cutteridge however doesn't think young people will pay attention to these warnings and said adults can help.
She added: "As adults we need to portray and model better uses of social media and that sometimes means putting up photos where we don't look our best and being honest about our lives."
Listen to Helen Cutteridge speaking with Premier's Alex Williams: