Jurassic World Evolution 2

This is very easy and can be done in 15-20 minutes or less.

You can find Psychological Trauma on the new Challenge maps included in the update. Specifically, Washington State Wreckage mentions it in the Challenge description. I've read it also appears at Pennsylvania Headquarters but I've yet to try it.

Washington State Wreckage is perfect for this achievement so I recommend going for it there. You won't need to worry about completing the challenge and if you play on Easy you'll have sufficient money and you won't have to worry about income.

So, start up the challenge on Easy. Demolish all the existing fences and build a large enclosure around the 5 Kentrosaurus. They need quite a lot of space but there should be plenty of room to expand - build along most of the left side of the area to save some hassle. You can also fence in the pair of Pachy's, tranq. them or just ignore them.

Build up the basics (Science Centre*, Response Facility and Paleo-Medical Facility). Do not build a Viewing Gallery or anything related to guests.
* Possibly not required...

The Kentrosaurus should all be suffering from Psychological Trauma. You'll need to perform a Status Check and send the Paleo-Medical team to diagnose them.

To fix the Trauma, you need to do 2 things. First, you need to satisfy their needs - aside from space they need Ground Fiber, Forest and Water. The second requirement is that they are away from the public eye. No Viewing Galleries should be enough but you can also close the park (click on the Arrival Point and select the option there) to make sure.

Edit: Okay, 3 things... As TymanTheLong says in the comments, you also need a Scientist with the Psychologist trait. Fortunately you will always start with one on this challenge map.

Once these conditions are met, hover over one of the Kentrosaurus and you'll see a timer. It just so turns out that there are 5 of them, and you need to heal 5 for this achievement!

Once the counter, which is about 5 minutes, expires all 5 dinosaurs will be healed and this achievement will unlock. Pretty easy!