One way to be able to discuss depression and stress is objectively like in this video animation of how selective serotonin reuptake inhibitors work.[1] Prozac, described in this video, is used to treat both panic attacks and depression. Constant stress from triggers like a boss who insistently attacks and berates or from endless hours working on a project can deplete available serotonin which the body produces at a certain rate. Stress untreated can also in people with genetic preposition trigger more severe diseases like bipolar borderline personality disorder and schizophrenia. There are other chemical systems at play such as dopamine and epinephrine[2]. Another way to deplete available stores of serotonin is using MDMA (ecstasy) which releases all the stored serotonin in the brain at once, however, that chemical requires about three days without stress triggers to rebuild during which time a user will likely experience panic attacks which users often counter with SSRI or THC.
We can mitigate these problems with drugs or by natural means such as learning how thought patterns effect chemical states of the mind, having a low stress job, work in a high stress job without giving a shit -- care without caring, eating healthy balanced foods, and most important daily exercise.
A founder needs to realize that stressors are important motivators for productivity but they effect chemical balances in the body which hasn't evolved much in the last 40,000 years. Different employees will have different coping mechanisms and different types of chemical balances. When the chemical balances start to become off kilter there are several signs verbal and physical such as irritability and heavy shallow breathing. It helps to have an intuitive sense of these and make sure an employee doesn't cross a threshold or in the case an employee does it is a worthwhile investment to help.
[1] https://www.youtube.com/watch?v=ElJaPZtSHoU
[2] https://www.youtube.com/watch?v=ejq99wLEMTw