You may find it interesting that the presence of nonnative bushes (especially variegated ones) generally tended to severely worsen my mood even back in the days when I was unfluent in botany. They seemed very boring/depressing because they never visibly did much and were largely ignored by insects.
(Nowadays I still dislike their nonnativeness and frequent failure to support (native) insects of course, but after reading about the fascinating adaptions they had in their original habitats I softened on them and now like them somewhat. If given a choice between standing in a perfectly blank room and a blank room with a non-native plant in it, nowadays I’d choose the latter. However, this slight preference does not translate into any noticeable improvement in my psychological health; this is is contrast to articles I’ve read of people-who-aren’t-the-oversentimental-treehugger type still experiencing massive and obvious relief from the symptoms of, for example, depression after “spending time in nature”. And native plants/animals do not noticeably improve my mental health under normal circumstances either.)