Characterisation of psychological and neurocognitive processes accompanying functional seizures.

Objectives: To examine the relationship between clinical, psychological, and cognitive characteristics of adults with functional seizures.

Methods: This study describes baseline characteristics of one-hundred and seven participants with a documented diagnosis of functional seizures recruited to the Re-PROGRAM randomised controlled trial. Participants completed a semi-structured interview, neuropsychological assessment, and questionnaire measures via Telehealth.

Results: Participants reported low levels of trust in body sensations, high levels of negative ruminative thinking, dissociation, somatisation, anxiety, depression, severe levels of functional impairment, and poor quality of life. At a group level, they had normal neurocognitive function, including mental control, processing speed, attention, and executive function. Anxiety (73%), depression (68%), post-traumatic stress disorder (49%), migraine (63%) and chronic pain (52%) were common comorbidities. Forty-three percent reported a family history of dementia. Somatic symptoms were associated with depression, anxiety, dissociation, ruminative negative thinking, and lower scores on the 'Not-distracting' interoception scale. Poorer psychosocial functioning was associated with depression and dissociation. Reduced mental quality of life was associated with higher levels of depression, anxiety, dissociation, ruminative negative thinking, and lower scores on the 'Trusting' interoception scale. There were no associations between the clinical or psychological variables and seizure frequency or seizure classification. Neither cognitive impairment nor failure on effort testing were associated with the clinical or psychological factors, quality of life or psychosocial functioning.

Significance: This study highlights the burden of psychiatric and physical comorbidity; and the relationship between psychological factors and functional impairment in a large cohort of patients with functional seizures despite normal cognitive function.