Depression in Epilepsy: Ignoring Clinical Expression of Neuronal Network Dysfunction?

Self-control of epileptic seizures by nonpharmacological strategies

Despite the unpredictability of epileptic seizures, many patients report that they can anticipate seizure occurrence. Using certain alert symptoms (i.e., auras, prodromes, precipitant factors), patients can adopt behaviors to avoid injury during and after the seizure or may implement spontaneous cognitive and emotional strategies to try to control the seizure itself. From the patient's view point, potential means of enhancing seizure prediction and developing seizure control supports are seen as very important issues, especially when the epilepsy is drug-resistant. In this review, we first describe how some patients anticipate their seizures and whether this is effective in terms of seizure prediction. Secondly, we examine how these anticipatory elements might help patients to prevent or control their seizures and how the patient's neuropsychological profile, specifically parameters of perceived self-control (PSC) and locus of control (LOC), might impact these strategies and quality of life (QOL). Thirdly, we review the external supports that can help patients to better predict seizures. Finally, we look at nonpharmacological means of increasing perceived self-control and achieving potential reduction of seizure frequency (i.e., stress-based and arousal-based strategies). In the past few years, various approaches for detection and control of seizures have gained greater interest, but more research is needed to confirm a positive effect on seizure frequency as well as on QOL.

Depression and quality of life in Spanish-speaking immigrant persons with epilepsy compared with those in English-speaking US-born persons with epilepsy

OBJECTIVE

This study aimed to examine levels of depression and quality of life in Spanish-speaking (less acculturated) immigrants with epilepsy compared with those in English-speaking US-born persons with epilepsy (PWEs).

METHODS

The study included 85 PWEs - 38 Spanish-speaking immigrants with epilepsy and 47 US-born PWEs. All patients underwent video-EEG monitoring and completed depression and quality-of-life inventories in their dominant language (Spanish/English). Chart review of clinical epilepsy variables was conducted by an epileptologist.

RESULTS

Our study revealed that depression scores were significantly higher in Hispanic PWEs (21.65±14.6) than in US-born PWEs (14.50±10.2) (t (64.02)=-2.3, two-sided p=.025). Marital status, medical insurance, antidepressant use, seizure frequency, and number of antiepileptic drugs (AEDs) were tested as covariates in the ANCOVA framework and were not statistically significant at the 0.05 significance level. Fewer Hispanics were prescribed antidepressant medications (13.15% for Hispanics and 40.42% for US-born, χ(2) (1,85) 7.71, p=.005) and had access to comprehensive health insurance coverage (χ(2) (1,85)=13.70, p=0.000). Hispanic patients were also found to be receiving significantly less AEDs compared with their US-born peers (t (83, 85)=2.33, p=.02). Although quality of life was diminished in both groups, Seizure Worry was worse for Hispanics after accounting for potential effects of marital status, medical insurance, use of antidepressants, seizure frequency, and number of antiepileptic drugs (AEDs) ((1, 83), F=7.607, p=0.007).

SIGNIFICANCE

The present study is the first of its kind to examine depression and quality of life in Spanish-speaking US immigrants with epilepsy. Spanish-speaking immigrants with epilepsy have been identified as a group at risk. They demonstrated higher depression scores and more Seizure Worry independent of epilepsy and demographic characteristics compared with their US-born peers. The Hispanic group was receiving less treatment for depression, was taking less AEDs, and had less access to comprehensive health coverage compared with non-Hispanics.

Gender differences in depression, but not in anxiety in people with epilepsy

PURPOSE

Anxiety and depression are frequent comorbidities in people with epilepsy (PWE), but possible gender differences are often neglected. The aim of the present study was to analyze if men and women with epilepsy differ with regard to anxiety and depressive symptoms and to identify possible predictors.

METHODS

Adult consecutive PWE (N=302; 53% women) completed self-report questionnaires, including the depression module of the Patient Health Questionnaire (PHQ-9), the anxiety module of the Hospital Anxiety and Depression Scale (HADS-A) and the subscales "medication effects" and "seizure worry" of the Patient-weighted Quality of Life in Epilepsy Inventory-31-P (QOLIE-31-P).

RESULTS

There was no gender difference in extent of anxiety (p=.532), which was mainly due to higher anxiety levels in men compared to the general population. The gender difference in depressive symptoms was significant (p=.009), with female patients being more affected. The most important predictors for anxiety and depressive symptoms were detrimental effects of medication (QOL medication effects) and of seizure worry (QOL seizure worry). Moreover, these predictors were more closely associated with anxiety and depressive symptoms in men.

CONCLUSION

Future intervention studies could show whether providing more information about the illness and medication effects may improve anxiety and depression. Our results suggest that such interventions should be tailored to the different needs of men and women.

[About the comorbidity of affective and conversion disorders in epilepsy]

In this literature review, special attention is drawn to the pathogenesis of conversion disorders in patients with epilepsy, in particular, with psychogenic non-epileptic seizures. Diagnostic issues and pharmacotherapy of affective and conversion disorders in patients with epilepsy is discussed.

Suicidal risk, affective dysphoric disorders, and quality-of-life perception in patients with focal refractory epilepsy

OBJECTIVES

We aim to study the frequency of (suicidal ideation) in patients with focal refractory epilepsy and its possible association with factors such as perceived QOL (quality of life) and ASDD (affective somatoform dysphoric disorder) using the 2007 ILAE proposal to classify affective disorders of epilepsy.

METHODS

A total sample of 82 patients was divided into two groups depending on the presence of suicidal risk: (A) study group - with suicidal risk and (B) control group - without suicidal risk. Questionnaires, scales, interviews, and clinical charts were evaluated by professionals with expertise in neurology and epileptology (RAM and AGA), psychiatry (AGE), and neuropsychology (FGR). Suicidal risk was evaluated with the M.I.N.I. (Mini-International Neuropsychiatric Interview) suicidal module that specifies the current suicidal risk based on scores. Quality of life was evaluated with the Quality of Life in Epilepsy Inventory - 31 (QOLIE-31) survey. Logistic regression was conducted to ascertain if ASDD and QOL significantly predicted suicidal risk. The results were considered statistically significant when the p-value was <0.05.

RESULTS

Suicidal risk was present in 33 (40.3%) patients. It was classified as severe in 31.7% of the patients, and it was only present in cases with temporal lobe epilepsy (p=0.002). More than half (52%) of patients with ASDD had risk of suicide (p=0.006). The presence of ASDD was found to be a risk factor for suicidal risk (OR=3.86; IC=1.3-12.2). Patients with suicidal risk had a lower QOL score compared with patients without suicidal risk (57.8±16.9 vs. 46.0±18.2; p<0.05), and an affected QOL significantly increased suicidal risk (OR=2.9; CI=1.3-7.8). Multivariate analysis demonstrated that an impaired QOL (OR=2.2) and the presence of ASDD (OR=4.1) significantly increased the probability of having suicidal risk (x(2)=13.6; OR=5.2; p=0.009).

SIGNIFICANCE

Affective somatoform dysphoric disorder and low QOL perception increase, independently, the risk of suicide.

Sex differences in lateralization of semantic verbal fluency in temporal lobe epilepsy

When differences exist, women tend to outperform men on measures of verbal fluency, possibly due to greater bilateral language representation. Patients with temporal lobe epilepsy (TLE) have a higher rate of atypical cortical language representation than the general population, making them a population of interest for the study of language. For the current study, 78 TLE patients (51% male, 51% left temporal focus) underwent pre-surgical neuropsychological evaluations. Retrospective data analyses investigated the impact of seizure laterality and sex on letter and semantic verbal fluency. Results indicated an interaction between sex and laterality for semantic, but not letter, verbal fluency. Males with left TLE exhibited significantly worse semantic fluency than males with right TLE, whereas females' semantic fluency did not differ by seizure focus. These data indicate that females with TLE may indeed engage in more bilateral hemispheric processing of semantic verbal fluency, whereas males may be more reliant on left temporal cortical function for this task.

Temporal lobe epilepsy and affective disorders: the role of the subgenual anterior cingulate cortex

OBJECTIVE

Reduced deactivation within the default mode network (DMN) is common in individuals with primary affective disorders relative to healthy volunteers (HVs). It is unknown whether similar network abnormalities are present in temporal lobe epilepsy (TLE) patients with a history of affective psychopathology.

METHODS

17 TLE patients with a lifetime affective diagnosis, 31 TLE patients with no formal psychiatric history and 30 HVs were included. We used a visuo-spatial 'n-back' paradigm to compare working memory (WM) network activation between these groups. Post hoc analyses included voxel-based morphometry and diffusion tensor imaging. The Beck Depression Inventory-Fast Screen and Beck Anxiety Inventory were completed on the day of scanning.

FINDINGS

Each group activated the fronto-parietal WM networks and deactivated the typical DMN in response to increasing task demands. Group comparison revealed that TLE patients with lifetime affective morbidity showed significantly greater deactivation in subgenual anterior cingulate cortex (sACC) than either the TLE-only or the HVs (p<0.001). This effect persisted after covarying for current psychotropic medication and severity of current depressive/anxiety symptoms (all p<0.001). Correlational analysis revealed that this finding was not driven by differences in task performance. There were no significant differences in grey matter volume or structural connectivity between the TLE groups.

CONCLUSIONS

Our results provide novel evidence suggesting that affective psychopathology in TLE has a neurobiological correlate, and in this context the sACC performs differently compared with network activity in primary affective disorders.

Risk factors for suicide in epilepsy patients

ABSTRACT: 

Suicidal behavior is not uncommon in epilepsy patients. Risk factors for suicidal ideation are associated with social and vocational disturbances, such as low economic status, lack of social support and unemployment and psychiatric comorbidity. In epilepsy patients, interictal dysphoric disorder presents a depressive mood that may be associated with episodic suicidal ideation. Suicide may occur among patients with very severe epilepsy, but also in patients that recently achieved a complete seizure freedom. Recent research suggests that almost a third of epilepsy patients that endorsed suicidal ideation were euthymic or had only very mild depressive symptoms. People with epilepsy should be specifically asked about their psychiatric problems and potential suicidal ideation. Neurobiology of suicidal behavior in epilepsy patients is still unclear.

Validation of the Patient Health Questionnaire-9 (PHQ-9) for depression screening in adults with epilepsy

OBJECTIVE

This study aimed to assess the accuracy and operating characteristics of the Patient Health Questionnaire-9 (PHQ-9) for depression screening in adults with epilepsy.

METHODS

Tertiary epilepsy center patients served as the study population, with 237 agreeing to structured interview using the Mini-International Neuropsychiatric Interview (MINI), a "gold standard" instrument developed for rapid diagnosis of neuropsychiatric disorders, including major depressive disorder (MDD); 172 also completed the PHQ-9, and 127 completed both the PHQ-9 and the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) within two days of the MINI. Sensitivity, specificity, positive and negative predictive values, and areas under the ROC curves for each instrument were determined. Cut-points of 10 for the PHQ-9 and 15 for the NDDI-E were used, and ratings at or above the cut-points were considered screen-positive. The PHQ-9 was divided into cognitive/affective (PHQ-9/CA) and somatic (PHQ-9/S) subscales to determine comparative depression screening accuracy.

RESULTS

The calculated areas under the ROC curves for the PHQ-9 (n=172) and the PHQ-9/CA and PHQ-9/S subscales were 0.914, 0.924, and 0.846, respectively, with the PHQ-9 more accurate than the PHQ-9/S (p=0.002) but not different from the PHQ-9/CA (p=0.378). At cut-points of 10 and 15, respectively, the PHQ-9 had higher sensitivity (0.92 vs 0.87) but lower specificity (0.74 vs 0.89) compared with the NDDI-E. The areas under the ROC curves of the PHQ-9 and the NDDI-E showed similar accuracy (n=127; 0.930 vs 0.934; p=0.864).

SIGNIFICANCE

The PHQ-9 is an efficient and nonproprietary depression screening instrument with excellent accuracy validated for use in adult patients with epilepsy as well as multiple other medical populations.

Physiologic and cortical response to acute psychosocial stress in left temporal lobe epilepsy - a pilot cross-sectional fMRI study

Stress is commonly reported as a seizure precipitant in individuals with poorly controlled seizures including temporal lobe epilepsy. The aim of the study was to assess the neural and physiologic correlates of psychosocial stress response during functional magnetic resonance imaging (fMRI) and their relationship with seizure occurrence in patients with left temporal lobe epilepsy (LTLE). We enrolled 23 patients with LTLE and 23 age- and sex-matched healthy controls (HCs); all underwent fMRI with control math task (CMT) and stress math task (SMT) and pre-/post-fMRI salivary cortisol analysis (acute stress reactivity calculated as % reduction from post-stress to recovery baseline; dCORT). The Beck Depression Inventory-II (BDI-II) and Perceived Stress Scale (PSS-10) were administered. T-tests of performance and cortisol variables were performed. Processing and single-subject modeling of fMRI response to CMT positive feedback and SMT negative feedback, group comparisons, and whole-brain correlation of seizure occurrence and fMRI response in patients with poorly controlled LTLE were performed. Patients with LTLE and healthy controls were similar in demographics, math performance, heart rate, and PSS-10 scores (all p>0.05). Patients with LTLE exhibited greater dCORT (p=0.048) and lower BDI-II scores (p=0.016) compared with HCs. Patients with poorly controlled LTLE showed a positive association between seizure frequency and dCORT (r=0.73, p=0.016). Functional MRI activation to feedback was similar between groups, including midfrontal, temporal, parietal, and occipital regions. Regression analyses revealed no group differences to positive feedback, but, compared with HCs, patients with LTLE showed decreased activation to negative feedback in the left cerebellum/middle occipital/fusiform gyri, left hippocampus/parahippocampus, bilateral medial frontal/cingulate/superior frontal gyri, right postcentral gyrus/inferior parietal lobule, and right insula/postcentral gyrus (p<0.05, corrected). Patients with poorly controlled LTLE showed negative association between seizure frequency and activation in the bilateral subgenual anterior cingulate (p<0.05, corrected). This study is the first to characterize the cortical and physiologic responses to acute psychosocial stress and to show a significant relationship between seizure control in LTLE and both the hypothalamic-pituitary-adrenal axis and fMRI signal reactivity to acute psychosocial stress. These findings extend our understanding of the complex interplay between stress, physiologic stress markers, and seizures/epilepsy.

Severe hippocampal atrophy is not associated with depression in temporal lobe epilepsy

Depression in temporal lobe epilepsy (TLE) is common, is a strong predictor of subjective disability, and may have unique pathophysiological characteristics. Previous studies showed that reduced hippocampal volume is associated with significant depressive symptoms in patients with TLE. We utilized regions of interest analysis of high-resolution brain MRI and a reliable and valid measure of depressive symptoms to evaluate 28 consecutive adult subjects with video-EEG-confirmed TLE. Regions of interest were based on prior human and animal studies of mood and behavioral dysfunction. Forty-three percent of the entire group had significant symptoms of depression, defined by a Beck Depression Inventory (BDI) score of greater than 15. Total hippocampal volumes were significantly smaller in the group with BDI<15, (p<0.007). None of the subjects in the quartile with the smallest left hippocampal volume had a BDI score greater than 15 compared with 57% of the subjects in the upper three quartiles (p<0.008). No other limbic brain structures (amygdala, subcallosal gyrus, subgenual gyrus, gyrus rectus), or total cerebral volume were associated with depressive symptoms. Adequate hippocampal integrity may be necessary to maintain depression symptoms in mesial temporal lobe epilepsy. This finding also supports the possibility of a unique mechanism for depression in mesial temporal lobe epilepsy, such as hyperexcitable neuronal influence on the limbic network.

Biomarkers of epileptogenesis: psychiatric comorbidities (?)

The last decade has witnessed a significant shift on our understanding of the relationship between psychiatric disorders and epilepsy. While traditionally psychiatric disorders were considered as a complication of the underlying seizure disorder, new epidemiologic data, supported by clinical and experimental research, have suggested the existence of a bidirectional relation between the two types of conditions: not only are patients with epilepsy at greater risk of experiencing a psychiatric disorder, but patients with primary psychiatric disorders are at greater risk of developing epilepsy. Do these data suggest that some of the pathogenic mechanisms operant in psychiatric comorbidities play a role in epileptogenesis? The aim of this article is to review the epidemiologic data that demonstrate that primary psychiatric disorders are more frequent in people who develop epilepsy, before the onset of the seizure disorder than among controls. The next question looks at the available data of pathogenic mechanisms of primary mood disorders and their potential for facilitating the development and/or exacerbation in the severity of epileptic seizures. Finally, we review data derived from experimental studies in animal models of depression and epilepsy that support a potential role of pathogenic mechanisms of mood disorders in the development of epileptic seizures and epileptogenesis. The data presented in this article do not yet establish conclusive evidence of a pathogenic role of psychiatric comorbidities in epileptogenesis, but raise important research questions that need to be investigated in experimental, clinical, and population-based epidemiologic research studies.

Determinants of depression among patients with epilepsy in Athens, Greece

OBJECTIVE

Depression is common among patients with epilepsy. The aim of our study was twofold: to estimate the prevalence of a major depressive episode and to identify its determinants among patients with epilepsy treated in the largest Greek hospital in Athens.

METHODS

All consecutive patients with epilepsy that visited the epilepsy outpatient clinic of Evangelismos General Hospital were invited to participate in the study. Ninety-four patients met our inclusion criteria.

RESULTS

A diagnosis of a current major depressive episode was established in 21 out of 94 eligible to participate (22.3%) patients. Being a female was associated with a 19.68-fold increase in the odds of having a major depressive episode (95% CI 3.39-114.14, p=0.001); being unemployed was associated with a 6.46-fold increase in the odds of having a major depressive episode (95% CI 1.23-34.07, p=0.028), and each extra seizure experienced per month was associated with a 1.38-fold increase in the odds of having a major depressive episode (95% CI 1.03-1.85, p=0.031).

CONCLUSION

Unemployment, female gender, and seizure control are important determinants of a major depression episode among patients with epilepsy.

The use of the NDDI-E in Arabic to identify symptoms of depression of moderate or greater severity in people with epilepsy

AIM

The aims of the current study were to translate and to validate the NDDI-E to the Arabic language to be used as a screening instrument to identify moderately severe symptoms of depression in people with epilepsy.

METHODS

The English version of the NDDI-E was translated to Arabic and back translated to English by two independent translators. A total of 51 patients, aged 18-56years old, with a diagnosis of epilepsy, completed the Arabic versions of the Beck Depression Inventory (BDI-II) and the NDDI-E. Patients with BDI scores >20 were considered to be suffering from moderately severe depressive symptoms. Cutoff scores, sensitivity, specificity, and positive and negative predictive values of the NDDI-E to identify symptomatic patients on the BDI were calculated.

RESULTS

A sensitivity of 93.33% and a specificity of 94.44% were found with NDDI-E total scores >15. The positive predictive value was 87.5%, and the negative predictive value was 97.14%. Spearman's rank correlation between the BDI and the NDDI-E was high (r=.78, p=0.000, N=51). Internal consistency was at 0.926 (Cronbach's alpha).

CONCLUSION

The Arabic version of the NDDI-E appears to be a reliable and sensitive instrument in the identification of moderately severe or severe depressive symptoms in people with epilepsy, and it can be used with all Arabic-speaking patients.

Pathophysiology of mood disorders in temporal lobe epilepsy

OBJECTIVE

There is accumulating evidence that the limbic system is pathologically involved in cases of psychiatric comorbidities in temporal lobe epilepsy (TLE) patients. Our objective was to develop a conceptual framework describing how neuropathological, neurochemical and electrophysiological aspects might contribute to the development of psychiatric symptoms in TLE and the putative neurobiological mechanisms that cause mood disorders in this patient subgroup.

METHODS

In this review, clinical, experimental and neuropathological findings, as well as neurochemical features of the limbic system were examined together to enhance our understanding of the association between TLE and psychiatric comorbidities. Finally, the value of animal models in epilepsy and mood disorders was discussed.

CONCLUSIONS

TLE and psychiatric symptoms coexist more frequently than chance would predict. Alterations and neurotransmission disturbance among critical anatomical networks, and impaired or aberrant plastic changes might predispose patients with TLE to mood disorders. Clinical and experimental studies of the effects of seizures on behavior and electrophysiological patterns may offer a model of how limbic seizures increase the vulnerability of TLE patients to precipitants of psychiatric symptoms.

Psychiatric symptoms in children prior to epilepsy surgery differ according to suspected seizure focus

PURPOSE

Children and adolescents with epilepsy have an overrepresentation of psychiatric illness. However, few studies in pediatrics have characterized specific psychiatric conditions associated with seizure localization. In addition, degree to which psychiatric illness may be more prominent in children refractory to standard medical treatment for epilepsy is not known. The aim of this study was to assess psychiatric symptoms in children with medically refractory epilepsy and ascertain whether symptoms were associated with specific localization.

METHODS

Case records were reviewed for 40 children with medically refractory epilepsy at the time of their referral for presurgical evaluation. Patients received a clinical psychiatric evaluation and parents completed the Child Behavioral Checklist (CBCL). Seizure localization was verified by pediatric epileptologists, and suitability for surgical procedures was verified by neurosurgical specialists. Groups were compared based on localization of seizure foci, either in the temporal lobe or predominantly extratemporal.

KEY FINDINGS

The majority of the sample had psychiatric diagnoses and behavior problems, well beyond the level reported in chronic epilepsy populations. In addition, children with temporal lobe seizure foci had more CBCL behavioral problem categories rated in the clinically significant range, and also were more likely to have clinical diagnoses of depression.

SIGNIFICANCE

Routine psychiatric evaluation prior to epilepsy surgery may be important for pediatric patients with medically refractory epilepsy. Psychiatric illness, particularly depression, may be especially prominent for those with temporal lobe seizure foci.

Not all depression is created equal: sex interacts with disease to precipitate depression

Depression is a common mental disorder that co-occurs in other neurological and somatic diseases. Further, sex differences exist in the prevalence rates of many of these diseases, as well as within non-disease associated depression. In this review, the case is made for needing a better recognition of the source of the symptoms of depression with respect to the sex of the individual; in that, some disease states, which includes the neuroendocrine and immune reactions to the underlying pathophysiology of the disease, may initiate depressive symptoms more often in one sex over the other. The diseases specifically addressed to make this argument are: epilepsy, Alzheimer’s disease, cancer, and cardiovascular disease. For each of these conditions, a review of the following are presented: prevalence rates of the conditions within each sex, prevalence rates of depressive symptoms within the conditions, identified relationships to gonadal hormones, and possible interactions between gonadal hormones, adrenal hormones, and immune signaling. Conclusions are drawn suggesting that an evaluation of the root causes for depressive symptoms in patients with these conditions is necessary, as the underlying mechanisms for eliciting the depressive symptoms may be qualitatively different across the four diseases discussed. This review attempts to identify and understand the mechanisms of depression associated with these diseases, in the context of the known sex differences in the disease prevalence and its age of onset. Hence, more extensive, sex-specific model systems are warranted that utilize these disease states to elicit depressive symptoms in order to create more focused, efficient, and sex-specific treatments for patients suffering from these diseases and concurrent depressive symptoms.

Rates of DSM-IV mood, anxiety disorders, and suicidality in Australian adult epilepsy outpatients: a comparison of well-controlled versus refractory epilepsy

Despite recent research into the impact of seizure control on mood disorders in epilepsy, it is often assumed that rates of psychiatric disorders are higher in people with refractory rather than well-controlled epilepsy. We assessed the point prevalence of mood and anxiety disorders and suicide risk using the Mini International Neuropsychiatric Interview (MINI) in a consecutive sample of epilepsy outpatients from a tertiary referral center. One hundred and thirty patients, whose epilepsy was categorized as well-controlled versus drug-treatment-refractory epilepsy (69; 53% well-controlled epilepsy) were recruited. High rates of mood disorders (n = 34; 26%), anxiety disorders (n = 37; 29%) and suicide risk (n = 43; 33%) were found. However, there was no difference in rates of disorders or suicide risk for those with refractory versus well-controlled epilepsy. These results underscore the importance of assessment and management of psychopathology in all people with epilepsy, regardless of their seizure control.

Screening for major depressive episodes in Japanese patients with epilepsy: validation and translation of the Japanese version of Neurological Disorders Depression Inventory for Epilepsy (NDDI-E)

We validated and translated into Japanese the English version of the screening instrument Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) to identify major depressive episodes in patients with epilepsy. A total of 159 Japanese subjects with epilepsy underwent a psychiatric structured interview with the Japanese version of the Mini International Neuropsychiatric Interview (M.I.N.I.-J) followed by completion of the Japanese version of NDDI-E (NDDI-E-J). Twelve participants met the M.I.N.I.-J criteria of current major depressive episode. Participants had no difficulties completing the NDDI-E-J. Its Cronbach's alpha coefficient was 0.83 and a cut-off score greater than 16 provided a sensitivity of 0.92, a specificity of 0.89, and a negative predictive value of 0.99. The NDDI-E-J appears to be useful for primary care clinicians to screen for major depressive episodes in epilepsy patients. Routine use of this brief and self-administered instrument in busy clinical settings will likely improve management of depression in Japanese individuals with epilepsy.

Exploration of age and sex differences in depressive symptoms and illness attitudes for youth with epilepsy and juvenile rheumatic disease

The aim was to explore the relationship of youth age and sex to depressive symptoms and illness attitudes in youth with epilepsy and juvenile rheumatic disease. Youth with epilepsy or juvenile rheumatic disease between the ages of 7 and 19 years completed measures of depressive symptoms and illness attitudes. A significant 3-way interaction, Disease Group × Sex × Age, was found when predicting depressive symptoms. Post hoc analyses revealed a simple 2-way Disease Group × Age interaction for males and females. Younger males and adolescent females with epilepsy reported greater depressive symptoms than younger males and adolescent females with a juvenile rheumatic disease. Youth with epilepsy reported more negative illness attitudes than youth diagnosed with a juvenile rheumatic disease, but no other main effects or interactions were found. Results suggest early screening of depressive symptoms, with particular attention to younger males and adolescent females with epilepsy.

Depression but not seizure factors or quality of life predicts suicidality in epilepsy

The objective of this study was to determine prevalence and predictive risk factors of suicidality in a large sample of epilepsy outpatients. We prospectively examined 193 consecutive adult epilepsy outpatients for depression, including suicidal ideation. Demographic and epilepsy factors, medication toxicity and health-related quality of life were also evaluated. The prevalence of suicidal ideation within the past two weeks was 11.9%. Although medication toxicity, health-related quality of life and BDI scores were each associated with suicidal ideation in the bivariate analyses, only the BDI remained significant in the logistic regression analysis. About one-fourth of the subjects with suicidal ideation had no significant symptoms of depression. Recent thoughts of suicide are a common occurrence in the outpatient epilepsy clinic setting, but these are not predicted by gender, age, seizure factors, medication toxicity or self-perceived quality of life. Although depression is associated with suicidal ideation, about one-fourth of the suicidal subjects were euthymic or only mildly depressed.

Depression and epilepsy: epidemiologic and neurobiologic perspectives that may explain their high comorbid occurrence

Depression is the most frequent psychiatric comorbidity in people with epilepsy (PWE) with lifetime prevalence rates ranging between 30 and 35%. Multifactorial variables play a pathogenic role in the high comorbid occurrence of these two disorders. These variables were critically examined during an international symposium held in Chicago in September 2010, the results of which are presented in two companion manuscripts. The first manuscript summarizes new epidemiologic data highlighting the bidirectional relation between depression and epilepsy and related methodological issues in studying this relationship. An examination of the neurobiologic aspects of primary mood disorders, mood disorders in PWE and pathogenic mechanisms of epilepsy derived from studies in animal models and humans is allowing a better understanding of the complex relation between the two conditions. In the first manuscript, we review data from animal models of epilepsy in which equivalent symptoms of depression and anxiety disorders develop and, conversely, animal models of depression in which the kindling process is facilitated. Data from structural and functional neuroimaging studies in humans provide a further understanding of potential common pathogenic mechanisms operant in depression and epilepsy that may explain their high comorbidity. The negative impact of depression on the control of seizure disorders has been documented in various studies. In this manuscript, these data are reviewed and potential mechanisms explaining this phenomenon are proposed.

Depression symptoms as a function of duration of intractable or controlled epilepsy

We examined if depression symptoms in patients with intractable (IE) or controlled epilepsy (CE) differ and how long after onset of epilepsy these effects would be most pronounced. The NDDI-E was administered to all outpatients (n=358) seen in a comprehensive epilepsy program clinic over a two-year period. Patients who met inclusion criteria (n=223) completed a total of 431 NDDI-E surveys over this time. Patients with a diagnosis of IE (n=72) or CE (n=151) were compared as a function of time since their epilepsy onset, segmented into 10-year epochs. Depression symptoms were higher in patients with IE compared to CE at 10-<20 years and did not differ at other time points. This study reveals differences in depression symptoms as a function of duration of epilepsy. Attending to the dynamic nature of depression symptoms in different epochs of epilepsy may be an important treatment target in patients with epilepsy.

Psychiatric comorbidity in patients with pharmacoresistant focal epilepsy and psychiatric outcome after epilepsy surgery

There are only a few studies in which both preoperative psychiatric comorbidity in pharmacoresistant focal epilepsy and its outcome after epilepsy surgery have been investigated. In this study, 144 patients evaluated for epilepsy surgery received psychiatric examination, 84 proceeding to intervention were reassessed postoperatively. Preoperatively, 60% met criteria for ICD-10- or epilepsy-specific psychiatric diagnosis. Twenty-seven percent, predominantly female, suffered from dysphoric disorder (DD) associated with temporal epileptogenic foci. Prevalence of DD correlated with complex partial seizure frequency and presence of ictal fear suggesting limbic-cortical dysregulation. Psychotic syndromes were linked to a history of febrile convulsions and left-sided temporomesial epileptogenic foci. High seizure frequency and early epilepsy onset predisposed to the development of personality disorders. Postoperative assessment revealed 18% of patients with "de novo" interictal affective disorders after surgery. Symptoms in 48% of patients with preoperative affective syndromes and 60% of patients with DD remitted after surgery. Seizure freedom and improved psychosocial status predicted remission of preoperative psychopathology.

Determinants of health-related quality of life in pharmacoresistant epilepsy: results from a large multicenter study of consecutively enrolled patients using validated quantitative assessments

PURPOSE

To evaluate the relative contribution of demographic and epilepsy-related variables, depressive symptoms, and adverse effects (AEs) of antiepileptic drugs (AEDs) to health-related quality of life (HRQOL) in adults with pharmacoresistant epilepsy.

METHODS

Individuals with epilepsy whose seizures failed to respond to at least one AED were enrolled consecutively at 11 tertiary referral centers. HRQOL was assessed by the Quality of Life in Epilepsy Inventory-31 (QOLIE-31), AEs by the Adverse Event Profile (AEP), and depressive symptoms by the Beck Depression Inventory-II (BDI-II). Multivariate linear regression models were used to identify variables associated with QOLIE-31 total score and subscale scores.

KEY FINDINGS

Of 933 enrolled individuals aged 16 years or older, 809 (87%) were able to complete the self-assessment instruments and were included in the analysis. Overall, 61% of the variance in QOLIE-31 scores was explained by the final model. The strongest predictors of HRQOL were AEP total scores (β = -0.451, p < 0.001) and BDI-II scores (β = -0.398, p < 0.001). These factors were also the strongest predictors of scores in each of the seven QOLIE-31 subscales. Other predictors of HRQOL were age (β = -0.060, p = 0.008), lack of a driving license (β = -0.053, p = 0.018), pharmacoresistance grade, with higher HRQOL in individuals who had failed only one AED (β = 0.066, p = 0.004), and location of the enrolling center. Epilepsy-related variables (seizure frequency, occurrence of tonic-clonic seizures, age of epilepsy onset, disease duration) and number of AEDs had no significant predictive value on HRQOL. The AEP total score was the strongest negative predictor of HRQOL in the subgroup of 362 patients without depressive symptoms (BDI-II score <10), but even in this subgroup the BDI-II score was retained as a significant predictor.

SIGNIFICANCE

In individuals with pharmacoresistant epilepsy, AEs of medication and depressive symptoms are far more important determinants of HRQOL than seizures themselves. When seizure freedom cannot be achieved, addressing depressive comorbidity and reducing the burden of AED toxicity is likely to be far more beneficial than interventions aimed at reducing the frequency of seizures.

Cognitive-behavioral therapy for depression in patients with temporal lobe epilepsy: a pilot study

Depression has a high prevalence among patients with temporal lobe epilepsy (TLE). A pilot study was carried out to evaluate group cognitive-behavioral therapy (CBT) as a treatment for depression in patients with TLE. Twenty-three outpatients with TLE and major depressive disorder, according to DSM-IV criteria, were enrolled and divided into two groups to receive 16 weekly sessions of CBT. The primary outcome measures were depression severity (assessed with the Beck Depression Inventory) and quality of life (measured with the Quality of Life in Epilepsy-31). Sixteen patients (70%) completed at least 80% of the sessions. From week 8, CBT had a significant positive effect on severity of depression that lasted until the end of treatment. A significant improvement in quality of life was also observed. CBT seems to be a useful intervention for treating depression and improving quality of life in patients with TLE.

Paediatric postmarketing pharmacovigilance using prescription-event monitoring: comparison of the adverse event profiles of lamotrigine prescribed to children and adults in England

BACKGROUND

Using postmarketing pharmacovigilance data collected shortly after market authorization of lamotrigine in the UK, a study was conducted to compare the adverse event (AE) profiles of children and adults taking lamotrigine, using modified signal detection methods.

METHODS

Data from the lamotrigine Prescription Event Monitoring (PEM) study, an observational cohort study, were stratified by age and examined using summary statistics for adverse drug reactions (ADRs), reasons for stopping treatment, deaths and follow-up information. Incidence densities of AEs in children (0-17 years) and adults (> or =18 years) in the first month of treatment were compared with months 2-6 to examine whether the AE rates were different in these two periods. AE rates in children were compared with those in adults (proportional reporting ratio [PRR] and incidence rate ratios), to compare the AE profiles between these age groups.

RESULTS

The cohort included 2457 children and 7379 adults. Differences in the AE profiles between children and adults were observed. Rash (PRR 1.2) and Stevens-Johnson syndrome (PRR 4.5) were more commonly reported in children, and confusion more frequently in adults (PRR 6.3). In children, 33% of ADRs were reported to the Regulatory Authority compared with 44% in adults. A higher proportion of children stopped treatment due to lack of effectiveness (45% vs 38%). No deaths were attributed to lamotrigine.

CONCLUSIONS

This study demonstrated that signal detection methods can be used to detect quantitative and qualitative differences in the AE profiles between the first children and adults taking a newly licensed drug.

Antiepileptic drugs and suicidality

The risk of suicide in patients with epilepsy is significantly higher than the general population. There are many hypotheses as to the reasons for this, but the potential role of anti-epileptic drugs (AEDs) in increasing suicidality has recently been brought into question. In 2008, the U.S. Food and Drug Administration (FDA) published a warning after a meta-analysis of data from all clinical trials involving AEDs found a suicidality risk of 0.43 per 1000 patients in active drug arms of these clinical trials compared to a rate in the placebo arm of 0.22. While an increased risk for individual AEDs was found in two, the FDA decided to issue a warning for the entire AED class. While this decision and the meta-analysis findings have been considered controversial, and have created concern that this stated risk may dissuade use of AEDs by patients who would benefit from them, it has led to increased awareness of the risk of suicidality and psychiatric co-morbidity in this patient group. In this article, the association of epilepsy and AEDs with psychiatric disease and suicidality are reviewed, perspective as to the significance and limitations of the FDA’s findings are discussed, and some options for suicidality screening and their potential utility in clinical care are evaluated.

The effect of amygdala kindling on hippocampal neurogenesis coincides with decreased reelin and DISC1 expression in the adult dentate gyrus

Temporal lobe seizures can induce the proliferation and abnormal migration of newly generated dentate granule cells, but little is known about the molecular mechanisms that govern these pathological events. Reelin and DISC1 (disrupted-in-schizophrenia 1) are proteins that play a regulatory role in the maturation and integration of new neurons in the developing and adult brain. In this study, we examined whether amygdala kindling results in aberrant neurogenesis and altered expression of reelin and DISC1 in the adult dentate gyrus. Using doublecortin immunohistochemistry, we found that short-term kindling (i.e., 30 electrical stimulations) significantly increased the number of immature neurons in the dentate subgranular zone (SGZ), whereas long-term kindling (i.e., 99 electrical stimulations) did not. However, doublecortin-labeled neurons in long-term kindled rats showed greater dendritic complexity than they did in short-term kindled or control rats. We also found that long-term kindling decreased the number of reelin-positive cells and decreased DISC1 expression in the dentate granule cell layer and subgranular zone. Interestingly, kindling-induced changes in reelin and DISC1 expression coincided with the appearance of ectopically located Prox1-labeled granule cells in the hilus. These effects occurred independently of alterations in granule cell layer length, dentate volume, or the number of hilar neurons. Taken together, these findings suggest a novel role for DISC1 in the pathophysiology of temporal lobe epilepsy and further suggest that changes in reelin and DISC1 expression may contribute to aberrant neurogenesis in the kindling model.

Association of serotonin transporter promoter (5-HTTLPR) and intron 2 (VNTR-2) polymorphisms with treatment response in temporal lobe epilepsy

PURPOSE

Temporal lobe epilepsy (TLE) is the most common epilepsy and about 30% of patients have poorly controlled seizures. Neurobiology underlying responsiveness to medical treatment in TLE patients is unclear and there are currently no biological tests to predict course of the disease. Animal and human studies repeatedly suggested serotonergic dysfunction in subjects with TLE. We investigated association of serotonin transporter (5-HTT) gene polymorphisms with medical treatment response in patients with TLE.

METHODS

We analyzed 5-HTT gene linked polymorphic region (5-HTTLPR) in promoter and variable number of tandem repeats in the second intron of the 5-HTT gene (VNTR-2) in 101 consecutive subjects with TLE.

RESULTS

TLE patients with the combination of transcriptionally more efficient genotypes, i.e. 5-HTTLPR L/L and VNTR-2 12/12, had increased seizure refractoriness to antiepileptic medication therapy and shorter periods of seizure freedom, than subjects with other combinations of the 5-HTT genotypes. There were no other clinical or demographic differences among patient groups based on the 5-HTT genotypes.

CONCLUSION

Combination of the 5-HTT genotypes linked with higher 5-HTT gene expression was found to be associated with worse response to optimal drug therapy. Further studies should determine potential role of this 5-HTT genotype polymorphism in epileptogenesis.

Suicide in patients with epilepsy

Epilepsy and Risk of Suicide: A Population-Based Case–Control Study. Christensen J, Vestergaard M, Mortensen PB, Sidenius P, Agerbo E. Lancet Neurology 2007;6(8):693–698.

Background

Studies have linked epilepsy with an increased suicide risk, but the association might be modified by psychiatric, demographic, and socioeconomic factors.

Methods

Suicide cases were identified in the Cause of Death Register in Denmark from 1981 to 1997. Up to 20 controls, matched by sex, birth year, and calendar date, were assigned to each suicide case.

Findings

We identified 21,169 cases of suicide and 423,128 controls. In total, 492 (2.32%) individuals who committed suicide had epilepsy compared with 3,140 (0.74%) controls, corresponding to a three times higher risk (rate ratio [RR] 3.17 [95% CI 2.88–3.50]; p < 0.0001). The RR remained high after excluding those with a history of psychiatric disease and adjusting for socioeconomic factors (1.99, 1.71–2.32; p < 0.0001). The highest risk of suicide was identified in patients with epilepsy and comorbid psychiatric disease, even after adjusting for socioeconomic factors (13.7, 11.8–16.0; p < 0.0001). In individuals with epilepsy, the highest risk of suicide was found during the first half year after diagnosis was made (5.35, 3.43–8.33; p < 0.0001), and was especially high in those with a history of comorbid psychiatric disease (29.2, 16.4–51.9; p < 0.0001).

Interpretation

Individuals with epilepsy have a higher risk of suicide, even if coexisting psychiatric disease, demographic differences, and socioeconomic factors are taken into account. Our study identifies people with newly diagnosed epilepsy as a vulnerable group that require special attention. Depression and Suicide in Epileptic Victims: A Population-Based Study of Suicide Victims during the Years 1988–2002 in Northern Finland. Mainio A, Alamäki K, Karvonen K, Hakko H, Särkioja T, Räsänen P. Epilepsy Behav 2007; 11:389–393. Patients with epilepsy are known to have comorbid affective disorders and a higher risk for suicide compared with the general population. Epilepsy, depression, and suicidal behavior have been shown to have common pathogenic mechanisms in their etiology. We evaluated the association between epilepsy, suicidal behavior, and depression by using the comprehensive database of all suicides ( n = 1,877) committed in northern Finland during the years 1988–2002 with information on all hospital-treated somatic and psychiatric disorders. Hospital-treated epilepsy occurred in 1.3% of the victims. Compared with other suicide victims, those with epilepsy were more often female, were older, and had significantly more often suffered from depression. Epilepsy was first diagnosed 8.8 (3.9–11.6) years before suicide, and depression, about 1 year after epilepsy diagnosis. Interictal depression among patients with chronic epilepsy is often classified as atypical or chronic depression, or it can mimic a dysthymic disorder. Therefore, diagnosis and treatment of depression among patients with epilepsy constitute a great challenge in clinical practice.

Imaging of serotonin mechanisms in epilepsy

Advances in positron emission tomography (PET) techniques have allowed the measurement and imaging of neurotransmitter synthesis, transport, and receptor binding to be performed in vivo. With regard to epileptic disorders, imaging of neurotransmitter systems not only assists in the identification of epileptic foci for surgical treatment, but also provides insights into the basic mechanisms of human epilepsy. Recent investigative interest in epilepsy has focused on PET imaging of tryptophan metabolism, via the serotonin and kynurenine pathways, as well as on imaging of serotonin receptors. This review summarizes advances in PET imaging and how these techniques can be applied clinically for epilepsy treatment.

Handedness, alexithymia, and focus laterality as risk factors for psychiatric comorbidity in patients with epilepsy

The aim of the current study was to evaluate the effect of seizure lateralization, handedness, and alexithymia on psychopathology in patients with temporal lobe epilepsy. One hundred five patients were included in the study. The Hopkins Symptom Checklist--90 (SCL-90) and Toronto Alexithymia Scale (TAS-26) were used for psychopathological assessment of patients. Handedness was evaluated using Annett's scale. Among the patients studied were 74 right-handers and 31 left-handers, and 25 alexithymic and 80 nonalexithymic persons. Left-sided foci were observed in 52, and right-sided foci in 53 persons. MANOVA was used for analysis of the interrelationship between nominal fixed factors (handedness, alexithymia, and focus laterality) and the dependent variables SCL-90, Hamilton Rating Scale for Depression, and Hamilton Rating Scale for Anxiety. MANOVA revealed that alexithymia exerts maximal effect on psychopathological variables, and maximal values of SCL-90 constructs were observed for persons with alexithymia/left-handedness and alexithymia/right-sided seizure focus combinations.

Monotherapy of epilepsy in women: psychiatric and neuroendocrine aspects

The aim of the present work was to perform a comparative assessment of the efficacy and safety of traditional and contemporary antiepileptic agents in women of reproductive age. The experimental group consisted of 65 patients, of whom 48 had partial epilepsy and 17 had idiopathic generalized epilepsy. A number of issues were addressed in studies of a larger group of patients (110), including both women (65) and men (45). The following agents were studied: Topamax, valproates, carbamazepine, and barbiturates, all used as monotherapy. Patients' status was evaluated using clinical (neurological, psychiatric), psychometric, neuropsychological, and hormonal parameters. The data led to the general conclusion that Topamax had advantages over the other study agents in the treatment of women with epilepsy.

Spike-wave discharges are necessary for the expression of behavioral depression-like symptoms

PURPOSE

The WAG/Rij strain of rats, a well-established model for absence epilepsy, has comorbidity for depression. These rats exhibit depression-like behavioral symptoms such as increased immobility in the forced swimming test and decreased sucrose intake and preference (anhedonia). These depression-like behavioral symptoms are evident in WAG/Rij rats, both at 3-4 and 5-6 months of age, with a tendency to aggravate in parallel with an increase in seizure duration. Here we investigated whether the behavioral symptoms of depression could be prevented by the suppression of absence seizures.

METHODS

Ethosuximide (ETX; 300 mg/kg/day, in the drinking water) was chronically applied to WAG/Rij rats from postnatal day 21 until 5 months. Behavioral tests were done before the cessation of the treatment. Electroencephalography (EEG) recordings were made before and after cessation of treatment to measure seizure severity at serial time-points.

RESULTS

ETX-treated WAG/Rij rats exhibited no symptoms of depression-like behavior in contrast to untreated WAG/Rij rats of the same age. Moreover, treated WAG/Rij rats did not differ from control age-matched Wistar rats. ETX treatment led to almost complete suppression of spike-wave discharges (SWDs) in 5-6 month old WAG/Rij rats. Discontinuation of chronic treatment was accompanied by a gradual emergence of SWDs; however, a persistent reduction in seizure activity was still present 47 days after discontinuation of the chronic treatment.

DISCUSSION

The results suggest that seizure activity is necessary for the expression of depression-like behavioral symptoms and confirm that epileptogenesis can be prevented by early and chronic treatment.

Co-morbidities in people living with epilepsy: hospital based case-control study from a resource-poor setting

PURPOSE

Evaluating co-morbidity in people living with epilepsy (PWE) is essential and its modification might improve their quality of life. We analyzed the various co-morbidities in PWE in comparison with the normal healthy controls.

METHOD

This prospective study was conducted from July 2006 to December 2007. PWE attending neurology outpatient services (n=250) with age ranging from 16 to 60 years (29.66+/-11.31 years; M:F 116:134) were recruited after obtaining informed consent. Healthy matched controls (n=250; 30.35+/-11.05 years; M:F 114:136) were also recruited.

RESULTS

The seizure types were: generalized (62.4%), complex-partial (21.6%), simple-partial (8.8%), and unclassified (7.2%). Sixty-nine percent were on monotherapy, and rest required polytherapy, with 90.8% on adequate dosages of anti-convulsants. About 83.2% were compliant and 70.4% had satisfactory control of seizures. At least 1 co-morbid condition was noted in 152 (60.8%) cases and among them, 62 (24.8%) had > or =2 co-morbidities. Control population was also evaluated for the presence of same co-morbidities and compared with cases. The various significant co-morbidities included: migraine (cases: 25.6% vs. controls: 15.2%; p=0.02), anxiety (cases: 2.4% vs. controls: 0%; p=0.04), depression (case: 5.2% vs. controls: 0.4%; p=0.0009), sleep disturbances (case: 6.8% vs. controls: 0.4%; p=0.0002), neurocysticercosis (cases: 15.6% vs. controls: 0%; p=<0.001), pulmonary tuberculosis (cases: 3.6% vs. controls: 0%; p=0.002) and extra-pulmonary tuberculosis (cases: 2.8% vs. controls: 0.4%; p=0.03). Less common co-morbidities were hypertension, diabetes, osteoarthritis, asthma, hypothyroidism, and acid-peptic disease.

CONCLUSION

In people living with epilepsy attending neurology OPD services, co-morbid illnesses were commonly observed compared to healthy controls.

Suicide and depression in the quantitative analysis of glutamic acid decarboxylase-Immunoreactive neuropil

BACKGROUND

Alterations of GABAergic neurotransmission are assumed to play a crucial role in the pathophysiology of mood disorders. Glutamic acid decarboxylase (GAD) is the key enzyme of GABA synthesis.

METHODS

Immunohistochemical staining of GAD 65/67 was performed in the orbitofrontal, anterior cingulate and dorsolateral prefrontal cortex (DLC), the entorhinal cortex (EC), the hippocampal formation, and the medial dorsal and lateral dorsal thalamic nuclei, with consecutive determination of GAD-immunoreactive (-ir) neuropil relative density. The study was performed on paraffin-embedded brains from 21 depressed patients (14 of whom had committed suicide) and 18 matched controls. The data were tested using Kruskal-Wallis, Mann-Whitney (U) and Spearman statistical procedures.

RESULTS

As shown by post-hoc U-tests, an increase in the relative density of GAD-ir neuropil was present in the hippocampal formation, specific for suicidal patients. The EC was the only area where non-suicidal patients also revealed an increase compared with controls. On the contrary, the DLC was the only area where a significant decrease existed, specific for non-suicidal patients. Numerous negative correlations were found between the investigated parameter and psychotropic medication.

LIMITATIONS

A major limitation of this study is the relatively small case number. A further limitation is given by the lack of data on drug exposure across the whole life span. The possible impact of unipolar-bipolar dichotomy of mood disorders on the obtained results should also be considered.

CONCLUSION

The study, revealing predominantly an increased relative density of GAD-ir neuropil, suggests the diathesis of GABAergic system specific for depressed suicidal patients.

Neurocognitive and behavioral functioning in frontal lobe epilepsy: a review

Frontal lobe epilepsy (FLE) is a seizure disorder with a lower prevalence than temporal lobe epilepsy (TLE). Despite its consequences on cognitive and emotional well-being, the neuropsychology of FLE has not been well studied. By contrast, TLE has been studied meticulously, leading to a relevant understanding of memory and the functional characteristics of the temporal and limbic circuits. The neuropsychological studies on FLE report deficits in motor coordination and planning, reduced attention span, and difficulties in response inhibition in complex cognitive tasks. This review aims to illustrate the most relevant neurocognitive dimensions, psychiatric comorbidity, and postoperative neuropsychological outcome of FLE. Methodological suggestions for future research are also included by critically reviewing the existing literature.

Consensus statement: the evaluation and treatment of people with epilepsy and affective disorders

Affective disorders in people with epilepsy (PWE) have become increasingly recognized as a primary factor in the morbidity and mortality of epilepsy. To improve the recognition and treatment of affective disorders in PWE, an expert panel comprising members from the Epilepsy Foundation's Mood Disorders Initiative have composed a Consensus Statement. This document focuses on depressive disorders in particular and reviews the appearance and treatment of the disorder in children, adolescents, and adults. Idiosyncratic aspects of the appearance of depression in this population, along with physiological and cognitive issues and barriers to treatment, are reviewed. Finally, a suggested approach to the diagnosis of affective disorders in PWE is presented in detail. This includes the use of psychometric tools for diagnosis and a stepwise algorithmic approach to treatment. Recommendations are based on the general depression literature as well as epilepsy-specific studies. It is hoped that this document will improve the overall detection and subsequent treatment of affective illnesses in PWE.

The use of neuroimaging to study behavior in patients with epilepsy

Structural and functional neuroimaging continues to play an increasing role in the presurgical evaluation of patients with epilepsy. In addition to its value in localizing the epileptogenic zone and eloquent cortex, neuroimaging is contributing to our understanding of mood comorbidity in epilepsy. Although the vast majority of research has focused on patients with temporal lobe epilepsy (TLE), neuroimaging studies of patients with extratemporal epilepsy and primary generalized epilepsy are increasing in number. In this review, structural and functional imaging modalities that have received considerable research attention in recent years are reviewed, and their strengths and limitations for understanding behavior in epilepsy are assessed. In addition, advances in multimodal imaging are discussed along with their potential application to the presurgical evaluation of patients with seizure disorders.

Direct enhancement of hippocampal dopamine or serotonin levels as a pharmacodynamic measure of combined antidepressant-anticonvulsant action

The neurobiological relationships between epilepsy and depression are receiving increased experimental attention. A key role for limbic monoamines in depression has been established and we recently showed the importance of hippocampal monoamines in limbic seizure control. We here studied whether anticonvulsant compounds are antidepressant and can elevate hippocampal dopamine (DA) or serotonin (5-HT) levels determined by in vivo microdialysis in rats. We used assessment of seizure severity in the focal pilocarpine model, antidepressant-like activity within the rat forced swim and the mouse tail suspension tests, and locomotor activity in an open field as behavioural tests. We studied the tricyclic antidepressant imipramine, the selective 5-HT reuptake inhibitor citalopram and the selective DA reuptake blocker GBR-12909. These compounds with combined antidepressant-anticonvulsant properties all directly enhanced extracellular hippocampal DA or 5-HT levels. Since glutamate-mediated hyperexcitability in temporal lobe regions seems to be involved in disturbed emotional behaviour, we next investigated possible antidepressant effects and hippocampal DA or 5-HT modulations exerted by selective ionotropic and metabotropic glutamate receptor ligands with anticonvulsant properties. Combined anticonvulsant-antidepressant activities of the NMDA antagonist MK-801 and the mGluR group I antagonists (AIDA, MPEP) were also associated with locally elicited increases in hippocampal DA and/or 5-HT levels. This study highlights that the hippocampus is an important site of action of combined anticonvulsant-antidepressant and monoamine enhancing effects.