How Childhood Maltreatment Is Related to Suicidality, Bipolarity and Central Serotonergic Activity in Patients with Major Depressive Disorder: A Cross-Sectional Pilot Study

Objective-The aims of this study were to determine whether childhood maltreatment contributes to the occurrence of major depressive disorder (MDD) with bipolarity, and whether there is a relationship between central serotonergic activity, as assessed using loudness dependence of auditory evoked potentials (LDAEP), and childhood maltreatment. Methods-Thirty-five MDD patients were stratified according to the presence or absence of childhood trauma into two subgroups, childhood trauma (CT) and no childhood trauma (NCT), using the Korean version of the Childhood Trauma Questionnaire (K-CTQ). The CT group was subjected to further analysis. Several psychometric ratings were also applied. In addition, auditory processing for the loudness dependence of auditory evoked potentials (LDAEP), which was used as a marker of serotonergic activity, was measured before beginning medication. Results-There was a significant difference in total Korean Bipolar Spectrum Disorder Scale score between the CT and NCT groups (t=-2.14, p=0.04). The total K-CTQ score was positively correlated with the total Beck Scale for Suicidal Ideation (BSS) score (r=0.36, p=0.036). In particular, emotional abuse was positively correlated with the total Barratt Impulsiveness Scale (r=0.38, p=0.026), BSS (r=0.38, p=0.025), and Hamilton Depression Rating Scale (HAMD) (r=0.36, p=0.035) scores. There was also a positive correlation between LDAEP and total Hypomania Personality Scale (r=0.49, p=0.02) and HAMD (r=0.58, p=0.004) scores within CT group. Conclusion-The findings of this study support that there is a relationship between childhood maltreatment and bipolarity in patients with MDD.