This study investigated the combinational risk factors influencing the long-term trajectory of posttraumatic stress disorder (PTSD) symptoms in 624 individuals severely affected by the Great East Japan Earthquake. Using the Massive Parallel Limitless-Arity Multiple-testing Procedure (MP-LAMP), the study identified 56 significant combinational risk factors, including 15 independent variables, which were not detected by conventional bivariate analysis. The strongest association was found with the combination of short resting time, short walking time, unemployment, and evacuation without preparation. The results highlight the importance of comprehensive combinational analysis for understanding multifactorial psychiatric symptoms.

Yuta Takahashi, Kazuki Yoshizoe, Masao Ueki, Gen Tamiya, Yu Zhiqian, Yusuke Utsumi, Atsushi Sakuma, Koji Tsuda, Atsushi Hozawa, Ichiro Tsuji, Hiroaki Tomita