Table 1_Direct and indirect associations of hypochondriasis with suicidality in psychiatric outpatients: mediating roles of anxiety and depression.docx

IntroductionAlthough both hypochondriasis and suicidality are common in psychiatric patients and related to anxiety and depression, their association in psychiatric patients remains unclear. This study investigated the direct association of hypochondriasis with suicidality and the indirect associations via anxiety and depression in psychiatric patients.
MethodsClinical records of 5484 psychiatric outpatients were reviewed. Hypochondriasis, Suicidality, Anxiety, and Depression were evaluated using the hypochondriasis item of the Hamilton Depression Rating Scale, the suicidality item of the 17-item Hamilton Depression Rating Scale (HAM-D17), the Hamilton Anxiety Rating Scale (HAM-A), and the 6-item subscale of the Hamilton Depression Rating Scale (HAM-D6), respectively. The associations among Hypochondriasis, Suicidality, Anxiety, and Depression were examined using a parallel mediation model. The model was estimated using the lavaan package in R with 10, 000 bootstrap resamples, adjusted for age and sex. Moderation by age and sex was also investigated.
ResultsSignificant positive indirect associations via Anxiety (point estimate = 0.05, 95% CI [0.03, 0.06]) and Depression (point estimate = 0.17, 95% CI [0.15, 0.19]) were observed between Hypochondriasis and Suicidality. Conversely, the direct association between Hypochondriasis and Suicidality was also significant but in a negative direction (B = −0.16, p <.001). As the total indirect association was stronger than the direct association, the total association of Hypochondriasis with Suicidality was significantly positive (B = 0.05, p = 0.002). The negative direct association of Hypochondriasis with Suicidality was significantly stronger in younger patients (interaction term = 0.004, p <.001).
ConclusionAnxiety and depression mediated the association between hypochondriasis and increased suicidality. In contrast, hypochondriasis was associated with decreased suicidality after accounting for the mediators. As the indirect association was stronger than the direct association, hypochondriasis was associated with increased suicidality overall. The direct association between hypochondriasis and decreased suicidality was stronger in younger patients.