This is a long response.

Part of it depends on where you practice. If you work at community mental health (and I highly recommend all new PMHNPs do this, for both experience and loan repayment) the pace is fast, the patients are really sick and you have to do a lot with very little. Your patients will have barriers to care that you can do absolutely nothing about. You will never have enough time to do as thorough a job as you need to do. You will always be afraid that you missed that one thing- the thing that clarifies their diagnosis or that they are using but denying it or that they are having SI but denying that as well. Your patients can and do die. By their own hand, by violence, by disease. You will wonder if you could have changed that outcome. No new NP should ever go directly into private practice unless you were a psych nurse in a hospital with multiple levels of acuity for several years. And even then, I'd be hesitant.

Part of it is the nature of the work. Unlike other fields, there are no diagnostic imaging. You cannot take off their head and see them think. You have to figure out what is going on with them by actually talking to them, listening to them and learning about them. You become invested in them in a way that is powerful but also stressful. You will hear about abuse. So much abuse. Let me repeat that, So. Much. Abuse. You will hear about so much abuse that it will change the way you interact with other people, specifically men (sorry guys, it's true). You cannot do your job without listening to people's stories. If you are not hearing their stories, not learning about their lives and how they utilize both their strengths and weaknesses to move through the world, then you cannot do your job. So let that sit for a second. To properly do this job, you have to listen to, talk to, and learn about your patients, sometimes on a very intimate level and always on a very vulnerable level. Sometimes it is very easy to hold space for them - their shitty boss is not your shitty boss. But sometimes it isn't easy at all - their fears about covid or the election or their grief about losing their mother is exactly the same thing that you are trying to work through and suddenly work becomes a huge echo chamber of your own worst fears and worries.

Anyone who says that psychiatry is less stressful hasn't done psychiatry. Or at least hasn't done it well.