Depression, Fatigue Before Treatment
At the study's start, about a third of participants in both groups appeared to be mildly to severely depressed.
The patients also reported more fatigue than the general public, the researchers note.
Depression, Fatigue After Treatment
Depression and fatigue eased for both treatment groups, with bigger gains reported for patients taking Enbrel.
By the study's end, depressed patients had significant improvements in areas including sexual symptoms, interest, appearance, and work or other activities.
More patients taking Enbrel also reached the study's goal for improvement in joint and skin problems caused by psoriasis. That goal was reached by 47% of the Enbrel group, compared with 5% of the placebo group.
The most common side effects were reactions at the injection sites. Infections were more common in the Enbrel group but not by much, the researchers note.
"Surprisingly, the majority of patients in this study did not have significant depression at baseline, by contrast with what is known about the general psoriasis population," write Tyring and colleagues.
They suggest that the study's design might partly explain that. Patients were excluded if they had a history of psychiatric disorders that might interfere with study participation.
The study was partly designed by Immunex, which invented Enbrel. Immunex and Wyeth Research funded the study. Amgen, which now owns Immunex, provided "editorial assistance" in writing the paper, the researchers write.