This randomized controlled trial aims to compare the efficacy of methotrexate (MTX) monotherapy versus combined methotrexate and selective serotonin reuptake inhibitor (SSRI) therapy in patients with psoriasis and comorbid depression and/or anxiety. Participants will be randomly assigned to two groups: one receiving MTX alone and the other receiving MTX plus escitalopram. Clinical outcomes will be evaluated over a 6-month period, including psoriasis severity using the Psoriasis Area and Severity Index (PASI) and Body Surface Area (BSA), quality of life using the Dermatology Life Quality Index (DLQI), and psychological status using the Beck Depression Inventory (BDI), Beck Anxiety Inventory (BAI), Hamilton Depression Rating Scale (HAM-D), and Hamilton Anxiety Rating Scale (HAM-A). The study will assess whether combination therapy provides superior clinical and psychological outcomes.

Inclusion Criteria:

• Adults aged >18 and <60 years
• Moderate to severe psoriasis (PASI ≥10 or BSA ≥10%)
• Moderate to severe depression (BDI ≥20 or HAM-D ≥17) and/or moderate to severe anxiety (BAI ≥16 or HAM-A ≥25)

Exclusion Criteria:

• Current substance abuse
• Systemic psoriasis treatment within the past 3 months
• Pregnancy or breastfeeding
• Hypersensitivity to methotrexate or escitalopram
• Erythrodermic or pustular psoriasis
• Contraindications to methotrexate (e.g., hepatic disease or malignancy)