Combining cognitive behavioral therapy (CBT) with standardized medical care did not significantly reduce monthly frequency of dissociative seizures compared to standardized medical care alone, according to findings published in Lancet Psychiatry.1 However, the longest seizure free period was increased, alongside improvements in several secondary measures.
Patients with dissociative seizures, paroxysmal episodes distinctive from epileptic seizures or syncope, often have comorbid psychiatric difficulties. Laura H. Goldstein, PhD, of the department of psychology, King’s College London, United Kingdom, and colleagues previously published a proof-of concept study (N=66) in 2010, demonstrating that CBT can reduce dissociative seizure frequency up until 6 months, when differences disappeared.2 They expanded upon this study in a pragmatic, parallel group multicenter randomized control trial (CODES), the largest known to date.
The CODES trial included adult participants with dissociative seizures from 27 neurology or epilepsy services in England, Scotland, and Wales. To be eligible, patients had to experience dissociative seizures within 8 weeks of recruitment and have had them confirmed by EEG, evaluation by 2 consultants treating the patient, or expert review by the research team.
Patients were provided with a neurology information booklet on dissociative seizures and completed a seizure diary for each week of the study, collected every 2 weeks. They were split into 2 treatment groups: CBT plus standardized medical care (n=186) and standardized medical care alone (n=182). CBT was provided by 39 therapists overall. While clinicians and study participants were aware of treatment allocation, the outcome data collectors and trial statisticians were blinded.
Monthly seizure frequency, assessed within the last 4 weeks of the 12 month study, did not significantly differ between the groups (estimated incidence rate ratio [IRR], 0.78; 95% CI, 0.56-1.09, P =.144). The researchers also assessed 16 secondary outcome measures, 9 of which showed significant improvement with CBT. Notably, there was an increase in the longest period of seizure freedom, assessed in the last 6 months of the trial, for the CBT group (estimated IRR, 1.64; 95% CI, 1.22-2.20; P =.001).
The CBT group reported better quality of life (P =.010), less bothersome seizures (P =.020), lower psychological distress (P =.013), and fewer somatic symptoms (P =.008). However, there were no significant differences between the groups in terms of patient-reported seizure severity, seizure freedom in the last 3 months of study, anxiety, or depressive symptoms. Nonetheless, the CBT group experienced greater clinical improvement at 12 months as rated by patients and clinicians (estimated mean differences, 0.66 and 0.47; 95% CI, 0.26-1.04 and 0.21-0.73; P =.001 and <.001, respectively).
Study limitations included potential bias in clinician or patient assessments caused by knowledge of treatment allocation or from the natural progression of the disease, which may spontaneously improve regardless of intervention.
The researchers concluded, “this trial suggest that dissociative seizure-specific CBT could contribute to improvement in clinically important aspects of psychosocial functioning and perceptions of health among patients with dissociative seizures.”
1. Goldstein LH, Robinson EJ, Mellers JDC, et al. Cognitive behavioural therapy for adults with dissociative seizures (CODES): a pragrmatic, multicentre, randomised controlled trial. Lancet Psychiatry 2020;7:491-505.
2. Goldstein LH, Chalder T, Chigwedere C, et al. Cognitive-behavioral therapy for psychogenic nonepileptic seizures: a pilot RCT. Neurology 2010;74:1986–94.