In 1985, a long-term study of Swedish adolescents was begun in Gothenburg, Sweden. First, every eighth grader (4291 students born in 1970) was screened for anorexia nervosa (AN). This uncovered 254 teens with the disease, to be included in a long-term study. An additional 27 adolescents with anorexia who were born in the early 1970s were added to the study. The final study group included 51 patients with AN and 51 healthy gender-matched controls, bringing the total number of participants to 102.
Follow-up has been done every 10 years (the last at the 30-year mark), and the researchers were able to include all but 4 of the original group in the follow-up, for a 96% rate. Sandra Rydberg Dubros and colleagues noted that the outcome might be more favorable due to the fact that teens only were included and half the sample came from the general community (Br J Psychiatry.doi.org/10.1192/bpj.2019.11).
Results: Age and perfectionism played a role
There were no deaths, but as for full recovery, the outcome was the same as that reported in earlier long-term studies. Seventy-six of the original 102 patients had fully recovered. During the elapsed 30 years, participants had an eating disorder for 10 years, on average, and 23% did not receive psychiatric treatment. Good outcome was predicted by later age at onset among individuals with adolescent-onset eating disorders and premorbid perfectionism.
At an earlier follow-up point 18 years after the study was begun, 6 of the 51 participants with AN still had their eating disorder. Twelve years later, the researchers were very surprised to learn that the percentage of those with eating disorders had modestly risen, not fallen, as expected. The outcome was more favorable than most clinicians would expect, perhaps due to the non-clinical portion of the sample.