Comment on ‘The overlapping relationship among depression,anxiety,and somatic symptom disorder and its impact on the quality of life of people with epilepsy’

We found the research paper by Shen et al. ¹ to be insightful. The authors investigated the prevalence of depression, SSD (Social Support Deficiency), and anxiety – three of the most common emotional disorders in people with epilepsy (PWE) – and their impact on the quality of life (QOL) of PWE. The study revealed that depression had the greatest effect on the QOL of PWE, followed by SSD and anxiety. The QOL of PWE was negatively correlated with an increase in the number of comorbid emotional disorders. The authors suggest that screening for depression, SSD, and anxiety in PWE is necessary. However, it is important to note that psychiatric symptoms in epilepsy can be complex and atypical, so it is also crucial to consider Interictal Dysphoric Disorder (IDD), a condition specific to epilepsy, ² in the screening process. IDD is characterized by eight symptoms, including labile depressive symptoms and affective and specific symptoms.^2,3 The literature suggests that IDD alone is associated with comorbid psychiatric disorders, refractory complex partial seizures, earlier onset of epilepsy, and adverse effects of antiepileptic drugs. ⁴ Patients with IDD and additional psychiatric comorbidity had higher seizure frequency, higher levels of side effects from antiepileptic treatment, and lower QOL compared with patients with normal screening or patients with IDD as the only comorbidity. ⁵

To assess the possibility of IDD, two self-reported questionnaires are available: the Seizure Questionnaire (SQ) ⁶ and the Interictal Dysphoric Disorder Inventory (IDDI).^2,3 Both questionnaires evaluate the core symptoms of IDD, including anergia, pain, insomnia, fear/panic, anxiety, depression, euphoria, and irritability. The SQ includes questions to assess the eight key symptoms of IDD, while the IDDI comprises eight main inquiries and six additional questions that assess the time course of the disorder, duration of dysphoric symptoms, and their association with seizures or antiepileptic drug therapy. IDD is diagnosed when at least three of the eight key symptoms are present, of moderate or severe severity, and causing moderate or severe distress. The main difference between the two questionnaires is that the SQ requires evaluation by an examiner after completion, while the IDDI relies solely on self-evaluation.^2,3,6

In conclusion, recognizing IDD and other psychiatric conditions such as mood, somatoform, and anxiety is crucial for providing optimized antiepileptic and psychiatric treatment for PWE.