For a study, researchers investigated moderators of cognitive-behavioral therapy (CBT) treatment effects and outcome predictors at 12-month follow-up in the CODES Trial (N=368), which compared CBT plus standardized medical care (SMC) vs. SMC-alone for dissociative seizures (DS). Investigators used moderator analyses of baseline characteristics to determine who benefited from receiving CBT 12 months after randomization. Monthly DS frequency, psychosocial functioning (Work and Social Adjustment Scale – WSAS), and health-related quality of life (Mental Component Summary (MCS) and Physical Component Summary (PCS) SF-12v2 scores) were among the outcomes studied. When moderating effects were absent, investigators tested whether baseline variables predicted change regardless of treatment allocation. Moderator analyses revealed that participants with more (≥22) symptoms (Modified PHQ-15) or more than equal to 1 current (M.I.N.I.-confirmed) comorbid psychiatric diagnosis at baseline benefited more (P<0.05) from CBT on DS frequency. Gender moderated the effect of CBT on PCS scores; women performed better than men in the CBT + SMC group. Not receiving disability benefits, lower anxiety and depression scores (PCS, MCS, WSAS); shorter duration, younger age at onset of DS, employment, fewer symptoms, and higher educational qualification (PCS, WSAS); and a stronger belief in the diagnosis and CBT as a “logical” treatment were all predictors of improved outcome (MCS). Some clinically relevant variables that might be expected to moderate/predict outcome (e.g., maladaptive personality traits, treatment confidence) were irrelevant. The treatment interacted with the patient’s complexity. CBT was more likely to reduce DS frequency in people with more comorbidities. Other patient characteristics predicted outcomes regardless of the intervention received.