Psychopathological and peripheral levels of neurobiological correlates of obsessive-compulsive symptoms in patients with epilepsy: a hospital-based study

Abstract

Objectives: Obsessive-compulsive symptoms (OCSs) and disorder (OCD) are often underdiagnosed in the out-patient epilepsy clinic. This work aimed at determining the risks and comorbidities (psychopathological and neurobiological correlates) of OCSs in treated adults with idiopathic epilepsy recruited from a university hospital.

Methods: Psychiatric evaluation was done using DSM-IV (The Diagnostic and Statistical Manual of Mental Health Disorders). Obsessive-compulsive disorder was identified using the Mini International Neuropsychiatric Interview (MINI). The Beck Depression Inventory (BDI-II), Hamilton Anxiety Rating Scale (HAM-A), and Yale-Brown Obsessive Compulsive Scale (Y-BOCS) were used to determine the severity of the related psychiatric symptoms.

Results: Out of 474 patients screened, included in this study were 107 with no psychiatric symptoms and 188 with OCSs [classified as those with at least OCSs=93; mild OCSs=36; moderate, severe, and extreme OCSs=59]. A hundred healthy subjects were included as controls. Blood concentrations of serotonin, adrenaline, noradrenaline, and dopamine were measured. Compared with controls, patients with OCSs had higher frequencies of depression and anxiety. Low concentrations of serotonin, adrenaline, noradrenaline, and dopamine were reported regardless of the presence or the absence of psychiatric symptoms, OCS severities, and antiepileptic drug (AED)-related variables (dose and serum drug level). Significant correlations were identified between Y-BOCS, BDI-II, and HAM-A scores, age, age at onset, and concentrations of noradrenaline.

Conclusion: This study indicates that a) OCSs are common in patients with epilepsy. Male sex, age, duration of illness, seizure focus, lateralization, and intractability to AEDs are its main risks; b) depression and anxiety are comorbid psychopathologies; and c) serotonin, catecholamines, and dopamine are linked to epilepsy-related variables and its comorbid psychopathies but not to its medications.