うつ病の発症予防に対する感情的作業記憶トレーニングの効果 (CTE 2019)

実験的：positive emotion working memory (PEWM )training

The PEWM task is a computerized n-back task. The stimulus presents 2000ms. The longer stimulus duration compared to a standard n-back task is intended to allow participants to more elaboratedly process positive emotion. During the PEWM, each session has 25-35 minutes.

行動：positive emotion working memory(PEWM) training

Participants take 10 sessions of positive emotion working memory training with n-bak task of positive words for two-week at itinal and 8 booster sessions at 6 months follow-up.

実験的：negative emotion working memory (NEWM) training

The NEWM task was a computerized dual n-back task. The visual stimulus presents 500 milliseconds (ms), followed by a blank screen for 2500 ms. The auditory stimulus presents 500-950 ms at the same time. Participants monitor both modalities. Each session takes 25-35 minutes. The first three sessions started with 1 n-level. From the fourth session , it starts from 2 n-level. The tasks are adjusted difficulty on the participant's performance. When accuracy rates equal to or larger than 90% for both the auditory and visual response, participants give an option to advance a n level or keep the same level.

行動：negative emtion working memory(NEWM) training

Participants take ten 16 × (21 + n) trial sessions of NEWM with dual n-back task with sad facial pictures for visual modality and sad words for auditory modality for 2 weeks at initial and 8 booster sessions for 2 weeks at 6 months follow-up.

実験的：Positive attention bias Training (PABT)

The PABT task was a variation of the computerized visual dot-probe task from a previous attention bias modification (ABM) study (Yang, et al., 2015, 2016). The stimuli present 2000 ms. The longer stimulus duration compared to a standard dot-probe task was intended to allow participants to have time to more fully process the content of the stimulus. During the PABT, 27 neutral-positive word pairs were presented 8 times (8 × 27) in each 10-min session.

行動：PABT

Participants take ten 216-trial sessions of PABT with 90% probe dot fallen on positive words for 2 weeks and eight 216-trial booster sessions for 2 weeks at 6 months follow-up.

プラセボコンパレーター：placebo (neutral attention bias training, NABT)

The placebo task was identical to the active PABT, except 90% of the probes appeared at the neutral position, 10% at the positive position.During the training, 27 pairs of neutral-positive words are presented 8 times (8 × 27) in each 10-min session. Participants take ten 216-trial sessions for 2 weeks at inital and 8 booster sessions for 2 weeks at 6 months follow-up.

行動：placebo (NABT)

Participants take ten 216-trial sessions of placebo training with 90% probe-dot fallen on neutral concrete words for 2 weeks at initial and 8 booster sessions for 2 weeks at 6 month follow-up.

Onset of a major depressive episode

Clinicians interviewed the participants using the Kiddie Schedule for Affective Disorders and Schizophrenia for School-Age Children (K-SADS) at initial, 6 months , 12 months and 24 months follow-ups after training and using Structured Clinical Interviews for Diagnostic and Statistical Manual of Mental Disorders, fifth edition ( SCID-5) at 5 years follow-up. The person has at least 4 depressive symptoms and mild to moderate impairment for a probable episode of major depression, or has 5 or more than 5 symptoms and mild to moderate impairment for a definite episode of major depression.

Self-reported depressive symptoms and clinical significant changes

Self-reported depressive symptoms assessed by Beck Depression Inventory-the second version (BDI-II). The BDI-II contains 21 questions, each with a score from 0 to 3. The total scores range form 21 to 60. To evaluate clinical significant changes of depressive symptoms, we follow the procedures outlined by Jacobson and Truax (Jacobson & Truax, 1991) . A participant is classified as meeting criteria for clinically significant change if (a) the post-training score falls within the range (mean ± 2 SDs) of the nonclinical population on the basis of BDI-II data (Yang, Wu, &Peng, 2012), and (b) if they display a statistically reliable reduction in scores from pre- to post- or to folloow-up assessment based to the reliable change index.