Clinical and sociodemographic variables associated with interictal dysphoric disorder and interictal personality in patients with drug-resistant temporal lobe epilepsy: A controlled study

- Psychiatric disorders have a high prevalence and negative impact on patients with epilepsy (PWE).
- It is necessary to identify behavioral conditions in PWE not present in psychiatric classifications.
- The presence of Interictal Dysphoric Disorder (IDD) and Interictal Personality (IP) was assessed.
- IDD was observed in 18 patients (18.4%) and IP in 36 (37.9%).
- Association between IDD and IP with clinical and sociodemographic factors were observed.

Psychiatric disorders (PD) have an elevated prevalence and an important negative impact on patients with epilepsy (PWE) since they are associated with lower quality of life and clinical refractoriness. However, it is also necessary to identify behavioral conditions possibly associated with epilepsy that are not part of the standard psychiatric classifications, such as Interictal Dysphoric Disorder (IDD) and Interictal Personality (IP). The frequency of IDD and IP in patients with drug-resistant temporal lobe epilepsy and mesial temporal sclerosis (TLE-MTS) was assessed. The Brazilian versions of the Neurobehavioral Inventory (NBI) and Interictal Dysphoric Disorder Inventory (IDDI) were applied to patients and to a control group. Psychiatric standard assessment was conducted through the Diagnostic and Statistical Manual for Psychiatric Disorders - 5th edition (DSM-5). The value of p considered significant was < 0.05. Ninety-five patients (51 women; 53.6%) and 50 controls (29 women; 58.0%) were assessed. Axis I PD were observed in 41 patients (43.1%). Interictal Dysphoric Disorder was observed in 18 patients (18.4%) and IP in 36 (37.9%). Interictal Dysphoric Disorder was associated with left-sided MTS (OR = 3.22; p = 0.008), previous psychiatric treatment (OR = 4.29; p = 0.007), and more than one AED used (OR = 2.73; p = 0.02) while presence of bilateral MTS (OR = 3.27; p = 0.008), longer disease duration (OR = 3.39; p = 0.006), and presence of Major Depressive Disorder (OR = 4.73; p = 0.004) were associated with IP. In the present study, there was a high prevalence of IDD and IP in patients with drug-resistant TLE-MTS; studies should be conducted to identify the presence of behavioral conditions that are not present in the conventional psychiatric classifications.