Comparing psychological factors associated with somatic symptoms and seizure frequency in people with epilepsy and functional seizures: Intolerance of uncertainty, anxiety, and depression.

AIMS: Research suggests a bi-directional relationship between physical and psychological health in seizure disorders. Intolerance of uncertainty (IU), anxiety sensitivity (AS), anxiety, and depression have been associated with poor outcomes across physical and mental health conditions. This cross-sectional study investigates relationships between these characteristics, somatic symptoms, and seizure frequency in people with epilepsy (PWE) or functional seizures (PWFS). METHODS: A convenience sample of 86 adults (41 PWE, 45 PWFS), with self-reported diagnoses was recruited online and through clinical services. Participants completed measures: IU (Intolerance of Uncertainty Scale-12), AS (Anxiety Sensitivity Index-3), depression (Patient Health Questionnaire-9), anxiety (Generalised Anxiety Disorder-7), somatic symptoms (Patient Health Questionnaire-15), in addition to questions regarding seizure condition and seizure frequency over the last four weeks. Regression analyses examined which variables were independently associated with (i) somatic symptoms and (ii) seizure frequency. RESULTS: There were no significant between-group differences for measures, however, scores were elevated in both groups relative to published non-clinical benchmarks. In regression analyses only the condition composite (depression and anxiety) was independently associated with somatic symptoms; PHQ-15 was the only variable associated with seizure frequency, but this finding was not robust to extreme values. Key limitations were self-reported diagnoses and highly skewed seizure frequency data. CONCLUSION: This study provides new insights into associations between IU, AS, anxiety, depression, and somatic symptoms in seizure conditions, finding elevated levels across measures in both PWE and PWFS. Results further establish the importance of assessing for and supporting with psychological factors affecting those living with seizure conditions.