(I'm being a little vague here, but given the still-extant stigma around "mental illness" and the amount of data collection that is now commonplace, I'm a bit paranoid about revealing enough to identify myself even under a throwaway account)
After ~20 years of on-and-off psychiatric treatment (some fairly intensive, some not, none especially effective), I found a psychiatrist with enough sense to strongly recommend that I get the relevant lab test. He had to tell me to request it from my primary care doc, because according to the worldview of American health insurance a psychiatrist is not qualified to order said lab test. My primary care doc gave me a questionnaire. My score was just below the threshold where the lab test is considered warranted. He told me he'd figure out how to make it work. I guess he did, because I got the test, got it interpreted by ${DOMAIN_EXPERT}, and got a prescription for treatment that seems to be working pretty well (albeit not perfectly).
After ~20 years of on-and-off psychiatric treatment (some fairly intensive, some not, none especially effective), I found a psychiatrist with enough sense to strongly recommend that I get the relevant lab test. He had to tell me to request it from my primary care doc, because according to the worldview of American health insurance a psychiatrist is not qualified to order said lab test. My primary care doc gave me a questionnaire. My score was just below the threshold where the lab test is considered warranted. He told me he'd figure out how to make it work. I guess he did, because I got the test, got it interpreted by ${DOMAIN_EXPERT}, and got a prescription for treatment that seems to be working pretty well (albeit not perfectly).