> I've lately been wondering if schizophrenia causes this connection-seeing, or if connections cause indicators of schizophrenia/psychosis.

IANAD, but my reading of the literature is that the genes for schizophrenia cause connection seeing, which on its own is mostly net neutral (slightly negative on average, but positive for many people). But it’s not having the ability to think critically about those connections, along with trauma and lack of social support, that causes this ability to see connections to manifest as mental illness. The genes for schizophrenia on their own though are, on average, only slightly net negative in terms of their impact.