Psoriasis is a chronic skin disease associated with considerable physical and psychological comorbidities. Stress and emotional disturbances have been implicated in both triggering the onset and exacerbation of psoriasis. In order to determine the level of perceived stress and mood alterations in patients with psoriasis and their association with disease severity, 300 individuals completed diverse validated questionnaires assessing stress and psychological mood. Evaluation of perception of disease was also measured. A significant association between psoriasis severity and mood, emotional disturbances and an impact on assessments of the quality of life were observed. Particularly, Montgomery-Asberg Depression Rating Scale, Hamilton Rating Scale and Hospital Anxiety and Depression Scale for Depression detected a significant risk for depression in relation to the disease severity. The association between depression features, anxiety and perceived stress with psoriasis severity is important and can influence the appropriate management of psoriasis.