Evaluating the Role of IL-17 as an Orchestrator of Peripheral-central Cross Talk in Depressive Symptoms

Initial dosing of Secukinimab at week 0, 1, 2, 3, 4 and maintenance doses will be determined by the standard care team. This will be 150mg or 300mg. This will be administered by the study team once confirmed and randomisation has occurred for secukinimab/ placebo allocation.

Initial dosing of bimkizumab at week 0 \& 4 and maintenance doses will be determined by the standard care team. This will be 160mg or 320mg. This will be administered by the study team once confirmed and randomisation has occurred for bimekizumab/ placebo allocation.

Initial dosing of Ixekizumab at week 0 \& 4 or week 0, 2 \& 4, maintenance doses will be determined by the standard care team. The initial dose will be 160mgs then 80mg dose will either be given 2 or 4 weekly. This will be administered by the study team once confirmed and randomisation has occurred for Ixekizumab/ placebo allocation.

Sodium chloride 0.9% for injection will be used as a placebo. A 1ml volume will be drawn up into a suitable sized syringe and labelled in accordance with standard practice at site. The dose will be administered as a subcutaneous injection in line with the Secukinumab/ Bimekizumab/ Ixekizumab dosing regimen. No dose adjustments are permitted.