Can Kaddish be said when a non Jew is going through a tough patch?

I was in the synagogue for prayers on Friday evening. I read in the siddur there is half Kaddish and full Kaddish. Furthermore, I believe we said half Kaddish on Friday. Can a non Jew recite when they are going through a rough patch? Because it says it is a mourner’s prayer. If not, what prayers can you suggest a non Jew going through a rough patch in life? There’s always Tehillim but which ones specifically and anything else besides Tehillim? I found the Parashat Veyeshev very inspiring too.

However, when I looked it up on Halachpedia, it seems it has to be recited during different situations as listed here in the halachpedia.