This is an ethics-approved, multi-national, multi-site Phase IV, 1-cohort prospective observational study. The main purpose of this study is to assess the effect of tildrakizumab on the overall wellbeing in patients with moderate-to-severe psoriasis using the 5-item World Health Organization Wellbeing Index (WHO-5) questionnaire.

Inclusion Criteria:

• Patient with diagnosis of moderate-to-severe chronic plaque psoriasis documented in the medical chart.
• Patient who need systemic biologic therapy and qualify for treatment with an IL-23p19 inhibitor. Tildrakizumab must be the anti-IL-23p19 selected therapy before including the patient in the study.
• Patient aged 18 years or older at the time of patient recruitment.
• Patient who have provided written informed consent (if required by country regulations).

Exclusion Criteria:

• Patients unable to comply with the requirements of the study (fulfilling of the study questionnaires) or who, in the opinion of the study physician, should not participate in the study.
• Patients included in a clinical trial.

The study population consists of patients with moderate-to-severe plaque psoriasis who need systemic biologic therapy and qualify for treatment with an IL-23p19 inhibitor treatment in real-world clinical practice.