Cross-national differences in hypochondriasis symptoms between Korean and American outpatients with major depressive disorder.

Hypochondriasis is defined as the tendency to worry excessively about having a serious illness. This study aimed to investigate cross-national differences in hypochondriasis symptoms between Korean and American patients with major depressive disorder (MDD). This study examined 1592 Korean and 3744 American MDD outpatients of age ≥18 years using the Hamilton Rating Scale for Depression (HAM-D) and the Quality of Life Enjoyment and Satisfaction Questionnaire (Q-LES-Q-SF). Korean MDD patients exhibited significantly higher scores for hypochondriasis than Americans after controlling for total HAM-D scores and demographic variables (p<0.0001), even though Americans had significantly higher total HAM-D scores (p<0.0001). Multivariate logistic regression analyses revealed that hypochondriasis was significantly associated with somatic and psychic anxiety, insomnia-middle, and suicide for both Korean and American MDD patients after adjusting for demographic covariates. Among all factors, somatic anxiety was the most strongly associated with hypochondriasis in both Korean (AOR=2.14, 95% CI 1.31-3.52) and American (AOR=1.98, 95% CI 1.69-2.31) MDD outpatients. Hypochondriasis symptoms are more prevalent among Korean than American MDD patients but appear to be associated with high levels of somatic anxiety regardless of culture. This suggests that cultural and personal factors play a shared role in the presentation of hypochondriasis symptoms.