Depression, catastrophising and repetitive negative thinking in patients with psychogenic non-epileptic seizures

A systematic review identified 34 studies allowing direct comparisons of depression in patients with psychogenic non-epileptic seizures (PNES) and patients with epilepsy. A meta-analysis found patients with PNES self-reported significantly higher levels of depression than patients with epilepsy. However, group differences in rates of clinical depression were less pronounced, suggesting either under-diagnosis or over self-reporting of depression in patients with PNES. Patients with PNES reported more physical symptoms of depression than those with epilepsy. Whilst depression had a similar effect on health-related quality of life in both patient groups, it was more closely associated with seizure-related variables in patients with epilepsy and interpersonal factors in patients with PNES. A core cognitive feature of depression is repetitive negative thinking, which is a common element of many psychiatric disorders. To explore repetitive negative thinking and catastrophising of seizures in patients with PNES and patients with epilepsy, 59 participants completed a series of self-report questionnaires and 29 also completed a masked and unmasked emotional Stroop task. Patients with PNES self-reported higher levels of repetitive negative thinking, catastrophising of seizures, anxiety and depression than patients with epilepsy; although no significant group differences were found on either emotional Stroop task. This suggested a difference between self-reported catastrophising of seizures and implicit seizure phobia. A possible link between repetitive negative thinking and emotional avoidance could account for these findings. The elevated levels of repetitive negative thinking in patients with PNES suggest this could be a target for psychological intervention.