TG and myalgic encephalomeyelitis/chronic fatigue syndrome: Concurrent use of thyroid hormone and an antidepressant occurred in six persons from the CFS group (5.3% of the whole group or 14.6% of persons with CFS who took antidepressants) and 4 from the ISF group (1.5% of the entire ISF group or 9.8% of persons with ISF who took antidepressants) but in none from the Well group (p-value for linear trend = 0.004, for the whole groups, p-value for linear trend = 0.22 for the subgroups on antidepressants).