Somatoform Disorders

Somatic Symptom Disorders

At present, 17+X randomized controlled trials (RCTs) for psychodynamic therapy (PDT) in somatic symptom disorders (somatoform disorders, medically unexplained symptoms) exist  (Abbass et al., 2020). The quality of studies is sufficient for most studies (Abbass et al., 2020).

• Efficacy (PDT vs control conditions): PDT is significantly superior to minimal treatment/treatment-as-usual or waiting list in improving somatic symptoms with a medium effect size (SMD= -0.47, 95% CI -0.70, -0.23, k=10, N=795, I2 = 55%) (Abbass, 2022). Compared to active controls, PDT achieved an effect size (SMD) of -0.41 (95% CI -0.74, -0.09, k=7, N=644, I2 = 70%) (Abbass, 2022). The width of the CI for reduction of somatic symptoms for the comparison with all controls  post therapy, 3-6 and more than 6 months after therapy (Δ=0.47, 0.49, 0.46) is comparable to that found in somatic symptom disorder for psychotherapy in general (Δ =0.47)(van Dessel et al., 2014).

• Stability: Effect sizes for somatic symptoms in 3-6 month-follow-ups were stable, but tended to decrease in follow-ups lasting longer than 6 months (Abbass, 2022; Leichsenring et al., 2023).

• PDT achieved a medium effect size compared to minimal treatment/treatment-as-usual or waiting list in improving physical functioning at short-term (-0.58, 95% CI -1.16, -0.01).

• Comparative efficacy: Five RCTs suggest that PDT was at least as efficacious as other bona fide therapies including CBT(Abbass et al., 2020).

• Adverse events: No or only a few adverse events were reported in studies of PDT in somatic symptom disorders, with no differences to other bona fide therapies(Chavooshi et al., 2017; Lumley et al., 2017; Yarns et al., 2020).

• Effectiveness under real world conditions: In a large naturalistic study a psychodynamic inpatient treatment achieved a response rate of 47% in patients with somatoform disorders(Steinert et al., 2019). In two other naturalistic studies, patients with dissociative seizures and chronic pain both responded to PDT with reduced symptoms and health care costs in long-term follow-up (Lilliengren et al., 2020; Russell et al., 2016).

• Mechanisms of change: There is evidence for mechanisms of change of PDT in somatic symptom disorders (Leichsenring et al., 2023).

• Cost-effectiveness: There is evidence that PDT is a cost-effective treatment in somatic symptom disorders(Creed et al., 2003). Two naturalistic studies found PDT to reduce health service costs in long-term follow-up after treating chronic pain (Lilliengren et al., 2020) and dissociative seizures(Russell et al., 2016).

Summing up, in somatic symptom disorders PDT achieves clinically significant effects in comparison to controls and seems to be as efficacious as other active treatments. In addition, PDT achieves clinically significant effects in improving functioning. Effects are stable in follow-ups. Furthermore PDT is efficacious under real world conditions and there is evidence for cost-effectiveness and mechanisms of change of PDT.

As a result, PDT fulfils the updated criteria of the American Psychological Association  for empirically supported therapies (Tolin et al., 2015), warranting a strong recommendation for the treatment of somatic symptom disorders  (Leichsenring et al., 2023)