Demi Lovato is an example of an artist who has been very vocal about her depression, eating disorder, and bipolar disorder, revealing that she struggled with suicidal thoughts as early as age 7. She further points out that such thoughts have reoccurred periodically throughout her life. Her story illustrates that the issue of depression is not so straightforward, and as pointed out in a similar post about Lady Gaga, it can't just go away -- relapses can happen, and that's totally normal and expected. Simon A. Rego, PsyD, a cognitive behavioral therapist, explains that "at least half of the people who have had a major depressive episode are at risk for more episodes down the road." https://www.refinery29.com/en-us/2018/03/194213/demi-lovato-depression-recovery-suicide-mental-health
Demi's story really brings out the nature vs. nurture question. She was a child star. When she was as young as 10 years old, she was already being subjected to the toxic nature of showbiz. She was likely predisposed to mental illness, but how much of her suffering had to do with or was exacerbated by a toxic workplace environment? Did her jobs have anything to do with her mental illness? A doctor with the National Institutes of Mental Health asserted that "It is not a question of genes versus environment. It is a question of how genes interact with whatever the environmental factors might be." Additionally, a psychiatrist at the University of Pittsburgh Medical Center“It’s also important to know that even if you don’t inherit a gene for mental illness, you can still have a genetic cause. Genes can alter after birth and contribute to mental illness also. This is called a de novo genetic change.” All these caveats make answering a simple question, much less simple.