Symptom retention after successful intensive trauma-focused treatment for post-traumatic stress disorder

<b>Background:</b> Evidence suggests that individuals undergoing successful treatment for post-traumatic stress disorder (PTSD) continue to experience PTSD symptoms. <b>Objective:</b> To determine the extent to which people continue to suffer from PTSD symptoms after intensive trauma-focused treatment and at six-month follow-up, despite no longer meeting diagnostic criteria for PTSD. <b>Method:</b> In total, 1015 individuals with PTSD participated in an eight-day intensive trauma-focused treatment programme combining psychoeducation, physical activity, prolonged exposure, and EMDR therapy. PTSD symptoms were assessed using the Clinician-Administered PTSD Scale for DSM-5 (CAPS-5) at baseline, post-treatment, and at six-months follow-up. Residual symptoms among those who no longer met PTSD diagnostic criteria were identified. Logistic regression analyses explored baseline predictors of the most persistent symptoms. <b>Results:</b> CAPS-5 total scores showed a significant reduction from pre- to post-treatment (<i>d</i> = 1.99) and remained improved at six-month follow-up (<i>d</i> = 1.48), despite a small to moderate increase in symptoms between post-treatment and follow-up (<i>d</i> = −0.38). Among those no longer meeting PTSD criteria post-treatment (75.8%) or at follow-up (63.2%), a substantial proportion (56.1% and 44.7% respectively) reported residual symptoms. The most frequently reported residual symptoms at six-months follow-up were negative beliefs (32.2%), negative feelings (28.7%), and intrusive memories (26.9%). The most persistent symptoms, based on odds ratios, were avoidance of thoughts or feelings (C1, OR = 0.03), intrusive memories (B1, OR = 0.04), and negative feelings (D4, OR = 0.05). Predictors of these residual symptoms included number of traumatic events, sexual trauma, suicidality, country of birth and receiving governmental income support. <b>Conclusions:</b> The results support growing awareness that, after seemingly successful trauma-focused treatment, a notable proportion of patients continue to suffer from specific PTSD symptoms. These findings underscore the importance of continued monitoring and tailored interventions targeting residual symptoms following treatment. Approximately half of the individuals in the current study who lost their diagnostic status post-treatment still experienced PTSD symptoms.The symptoms that were most likely to persist at the six-month follow-up were avoidance of thoughts or feelings, intrusive memories and negative feelings.These results underscore the complexity of interpreting treatment outcomes and highlight that the absence of a diagnosis does not guarantee the alleviation of symptoms and associated impairment. Approximately half of the individuals in the current study who lost their diagnostic status post-treatment still experienced PTSD symptoms. The symptoms that were most likely to persist at the six-month follow-up were avoidance of thoughts or feelings, intrusive memories and negative feelings. These results underscore the complexity of interpreting treatment outcomes and highlight that the absence of a diagnosis does not guarantee the alleviation of symptoms and associated impairment.