Skin condition associated with depression, anxiety and suicidal feelings

Psoriasis affects 1 percent to 3 percent of the general population, and estimates suggest 0.4 percent to 2.3 percent of adults have the condition but have not been diagnosed. "Psoriasis has long been recognized to be associated with potentially adverse effects on mental health," the authors write. "In the 1960s, a popular ad campaign labeled the emotional burden of this skin disease as the 'heartbreak of psoriasis.' However, there have been relatively few studies evaluating psychological outcomes in patients with psoriasis."

Shanu Kohli Kurd, M.D., M.S.C.E, M.H.S., and colleagues at the University of Pennsylvania, Philadelphia, studied data from electronic medical records in the United Kingdom from 1987 to 2002. The analyses included 146,042 patients with mild psoriasis, 3,956 patients with severe psoriasis and 766,950 patients without psoriasis (five control patients for each patient with psoriasis, selected from the same practice and similar entry dates). Patients were defined as having new-onset depression, anxiety or suicidality if corresponding diagnostic codes appeared in their records after follow-up began.

Of patients with mild or severe psoriasis, 25.9 per 1,000 individuals per year were diagnosed with depression, 20.9 per 1,000 per year with anxiety and 0.9 per 1,000 per year with suicidality. The rate of these cases attributable to psoriasis was 11.8 per 1,000 individuals per year for depression, 8.1 per 1,000 per year for anxiety and 0.4 per 1,000 per year for suicidality.

"Stated another way, the excess risk attributable to psoriasis is one case of depression for every 39 patients with severe psoriasis per year (or per 87 patients in patients with mild psoriasis per year)," the authors write. "The excess risks associated with psoriasis for anxiety and suicidality correspond to one case per 123 and 2,500 patients with psoriasis per year, respectively." Considering this data and the prevalence of psoriasis in the U.K., the authors estimate that there are more than 10,400 diagnoses of depression, 7,100 of anxiety and 350 of suicidality related to psoriasis each year.

"It is important to identify these psychiatric disorders because they represent substantial morbidity that can be improved with a variety of pharmacological and non-pharmacological approaches," the authors conclude. "Recent data suggest that psychiatric co-morbidity may negative affect response to certain psoriasis treatments (e.g., photochemotherapy), while other studies suggest that control of psoriasis is associated with improvements in psychological symptoms. Future studies are necessary to determine the mechanisms by which psoriasis is associated with depression, anxiety and suicidality as well as approaches to prevent such adverse outcomes in patients with psoriasis."