Researchers from Norway have recently published an investigation of thyroid function parameters amongst patients with psychosis who were treated with antipsychotics, comparing these people with healthy controls. 1345 patients with psychosis and 989 healthy controls all underwent assessment of medication data, and thyroid function tests. Lower levels of free T4 (median 13.70 vs 14.00, p < 0.001) were observed amongst psychotic patients treated with any antipsychotic in general (p = 0.001), and specifically with quetiapine (p = 0.003) and olanzapine (p = 0.018). Combined antipsychotics treatment in combination other psychotropic drugs, and particularly with antidepressants, was associated with a lower fT4 level (p < 0.001) than that observed with the use of antipsychotics alone. Another issue to monitor for during extended antipsychotic treatment.