An estimated 46.6 million U.S. adults struggle with mental illnesses, such as anxiety disorder, according to the National Institute of Mental Health.

But you don't have to be clinically diagnosed with a mental illness to experience the symptoms and effects of stress and anxiety, especially in the workplace. For millennials, specifically, research suggests that money and work are the biggest factors contributing to their stress.

Now, a recent survey from Mind Share Partners, a nonprofit that works with companies to improve mental health resources, examines the effects that mental health issues can have on employees.

For the survey, 1,500 people ages 16 and older who are employed at a company with at least 11 employees answered questions online about their mental health.

The survey questions included how often they experience mental health symptoms (for example, "sweating, rapid heartbeat, trembling, upset stomach, dizziness, or fainting"), how it impacts their work and whether they felt like they have adequate mental health support and resources in their workplace.

According to the findings, which are published in Harvard Business Review, 60% of people have experienced symptoms of mental health issues in the past year.

Further, half of millennial (defined in this survey as 23-38 years old) and 75% of Gen-Zer (18-22 years old) respondents have left a job, both voluntarily and involuntarily, partially due to mental health reasons. (To put that in perspective, only 20% of the total survey respondents reported doing the same.) For baby boomers (55-73 years old), the number was the lowest, with less than 10% leaving a job for mental health-related reasons.