Apparently the connection between 120+ IQ and mental health problems doesn't necessarily come from pressure alone, high IQ people have numerous issues, some of them caused by pressure, some by Society (understanding "everything" that is wrong when laid out and seemingly nobody gives a shit is kinda problematic for "us") and many are genetic corelations like Addiction, ADHD, Anxiety disorders, being more prone to depression, PTSD, OCD, Hoarding (rare) and many more.
There are measurements for humans to grasp them more accurately, but they can't be done with a shitty online test, they are done by Therapists or Psychiatrist or Psychologist. They basically take problem solving and logical skills (mostly what IQ is), Social Skills and some other measurements. They are more accurate at giving a good view about a person from a mind perspective. But keep in mind that the brain never stops developing and the scores change over time, especially problem solving and social skills can be trained over time or when left untrained, get worse.
There is a big impact of early life mathematics on IQ score for example, thats why African people score lower on the global average than for example European or North American people. However, a pressured environment seems to be counterproductive for development as seen in Japan South Korea and China for example, where children are in constant pressure to learn.