Verbal memory following weight gain in adult patients with anorexia nervosa: A longitudinal study.

BACKGROUND

Patients with Anorexia Nervosa (AN) show a moderate deficit in overall neuropsychological functioning. Since previous studies on memory performance mainly employed cross-sectional designs, the present study aims to investigate changes in verbal memory following weight-gain.

METHODS

Verbal memory was assessed with the Wechsler Memory Scale-Revised (WMS-R; 'logical memory'-story-recall-subtest) and the California Verbal Learning Test-II (CVLT-II; 'verbal learning'). Included were 31 female patients with AN (18 restricting-, 13 purging-subtype; average disease duration: 5.1 years; average baseline BMI: 14.4 kg/m2 ) and 24 medication-free normal-weight healthy women adjusted for age at baseline (T0). In a post-treatment assessment of approx. 6 weeks with weight increase (T1), 18 patients with AN and 20 healthy women were assessed again. Group differences in verbal memory (i.e., WMS-R, CVLT-II) were assessed for the baseline comparisons with a multivariate ANOVA and longitudinal data were analysed with repeated measures (RM) ANOVAs.

RESULTS

At baseline, patients with AN as compared to healthy women displayed deficits in logical memory. In the follow-up assessment, patients with AN improved their logical memory significantly compared to healthy controls (p < 0.006). Furthermore, groups did not differ in verbal learning neither before nor after inpatient treatment.

CONCLUSIONS

Enhanced logical memory in patients with AN following weight-gain is probably due to the impaired memory as compared to healthy controls at T0. A survivorship bias could explain the improved memory performance in longitudinal data in contrast to cross-sectional studies. Patients with AN with poorer memory performance before inpatient treatment are at higher risk to drop out and need support.