Depression and the risk of neurological disorders

Recent Advances in Neuroimaging of Epilepsy

Human neuroimaging has had a major impact on the biological understanding of epilepsy and the relationship between pathophysiology, seizure management, and outcomes. This review highlights notable recent advancements in hardware, sequences, methods, analyses, and applications of human neuroimaging techniques utilized to assess epilepsy. These structural, functional, and metabolic assessments include magnetic resonance imaging (MRI), positron emission tomography (PET), and magnetoencephalography (MEG). Advancements that highlight non-invasive neuroimaging techniques used to study the whole brain are emphasized due to the advantages these provide in clinical and research applications. Thus, topics range across presurgical evaluations, understanding of epilepsy as a network disorder, and the interactions between epilepsy and comorbidities. New techniques and approaches are discussed which are expected to emerge into the mainstream within the next decade and impact our understanding of epilepsies. Further, an increasing breadth of investigations includes the interplay between epilepsy, mental health comorbidities, and aberrant brain networks. In the final section of this review, we focus on neuroimaging studies that assess bidirectional relationships between mental health comorbidities and epilepsy as a model for better understanding of the commonalities between both conditions.

Neurocognitive and psychological profiles of adult patients with epilepsy in Hong Kong

Cognitive deficits and psychological impairments are often associated with seizures. In order to describe the neuropsychological profiles of adult patients with epilepsy (PWEs) in Hong Kong China, a total of 186 PWEs were recruited with 102 being drug-responsive and 84 being drug-resistant. Symptoms of depression, anxiety, and epilepsy-specific quality of life (QOL) were measured. Cognitive assessments consisted of intelligence, memory, verbal and visual abilities, and executive function. Neurocognitive impairments were prevalent among PWEs, and patients with drug-resistant epilepsy had significantly more impaired psychological and cognitive profiles. Thirty-nine percent and 30% of patients with drug-resistant epilepsy reported moderate to severe levels of anxiety and depression, respectively, versus 16% and 7% of patients with drug-responsive epilepsy. The most commonly occurring cognitive deficit was memory. Thirty-five percent to 47% of patients with drug-resistant epilepsy and 26% to 35% of patients with drug-responsive epilepsy were compromised in verbal recall memory. Our findings also suggested significant correlations between psychological well-being and cognitive performance. Patients who reported more psychological symptoms tended to perform worse in neurocognitive tests. Identification and management of neuropsychological difficulties in PWEs are important and should be included in primary epilepsy care.

Neuroimaging changes in mesial temporal lobe epilepsy are magnified in the presence of depression

OBJECTIVE

The aim of this study was to investigate differences in gray matter volume between patients with mesial temporal lobe epilepsy (MTLE) with and without depression using voxel-based morphometry.

METHOD

We included 48 adults with refractory MTLE (31 women, 39.18 ± 8.4 years) and 96 healthy controls (75 women, 37.11 ± 8.9 years). For the psychiatric evaluation, the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders, Axis I, was used for the diagnosis of depression, and the Beck Depression Inventory, for the determination of symptom intensity. All patients underwent an MRI scan. Patients were separated into two groups: those with MTLE with depression (n = 24) and those with MTLE without depression (n = 24). We performed voxel-based morphometric analysis, comparing patients with controls using the t test.

RESULTS

The number of areas of gray matter volume loss was higher in patients with MTLE with depression than in those with MTLE without depression.

CONCLUSIONS

The evidence of more widespread gray matter volume loss in patients with MTLE and depression calls our attention to the importance of timely recognition and treatment of depression in patients with MTLE and also to the bidirectional relationship between the two disorders and their frequent co-occurrence.

Are psychiatric disorders independent risk factors for new-onset epilepsy in older individuals?

This retrospective study examined whether psychiatric conditions are directly related to epilepsy or, rather, are associated with underlying central nervous system (CNS) disorders linked to subsequent epilepsy. We examined data from a sample of older veterans (>65 years) receiving care from the Veterans Health Administration during fiscal year 2000. We compared individuals with new-onset epilepsy and individuals without epilepsy to examine the extent to which psychiatric disorders were associated with new-onset epilepsy; this analysis controlled for demographic and premorbid neurological risk factors previously associated with new-onset epilepsy. Premorbid psychiatric conditions occurred at higher rates in the epilepsy versus nonepilepsy groups, foremost including depression (17% vs 12%), anxiety (12% vs 8%), psychosis (12% vs 5%), and substance abuse (8% vs 4%). However, in the final model, only psychosis (OR=1.4, CI 1.2-1.6) was significantly associated with epilepsy when controlling for neurological disorders and psychiatric conditions (e.g., stroke, dementia, brain tumor, head injury).

Conversion disorder and coexisting nonepileptic seizures in patients with refractory seizures

Nonepileptic seizures (NES) are commonly observed in patients with seizures resistant to antiepileptic drugs (AEDs). However, NES may be symptomatic of different diagnoses, in particular, conversion disorder (CD) and coexisting NES and epileptic seizures (CENES). We compared the clinical characteristics of these disorders in 219 patients with refractory seizures. The prevalence of NES was similar in children (11%) and adults (16%). In both groups, CENES represented the most frequent cause of NES (75%). In adults, CD was associated with a shorter duration of illness and normal neuroimaging and interictal EEG compared with the other groups. Patients with CD represented one-quarter of all patients with AED-resistant seizures with normal presentation during interictal investigations. In both children and adults with AED-resistant seizures, NES are frequently observed and are three times more likely to be CENES than CD.

Symptoms of epilepsy and organic brain dysfunctions in patients with acute, brief depression combined with other fluctuating psychiatric symptoms: a controlled study from an acute psychiatric department

BACKGROUND

In psychiatric acute departments some patients present with brief depressive periods accompanied with fluctuating arrays of other psychiatric symptoms like psychosis, panic or mania. For the purpose of the present study we call this condition Acute Unstable Depressive Syndrome (AUDS). The aims of the present study were to compare clinical signs of organic brain dysfunctions and epilepsy in patients with AUDS and Major Depressive Episode (MDE).

METHODS

Out of 1038 consecutive patients admitted to a psychiatric acute ward, 16 patients with AUDS and 16 age- and gender-matched MDE patients were included in the study. Using standardized instruments and methods we recorded clinical data, EEG and MRI.

RESULTS

A history of epileptic seizures and pathologic EEG activity was more common in the AUDS group than in the MDE group (seizures, n = 6 vs. 0, p = 0.018; pathologic EEG activity, n = 8 vs. 1, p = 0.015). Five patients in the AUDS group were diagnosed as having epilepsy, whereas none of those with MDE had epilepsy (p = 0.043). There were no differences between the groups regarding pathological findings in neurological bedside examination and cerebral MRI investigation.

CONCLUSION

Compared to patients admitted with mood symptoms fulfilling DSM 4 criteria of a major depressive disorder, short-lasting atypical depressive symptoms seem to be associated with a high frequency of epileptic and pathologic EEG activity in patients admitted to psychiatric acute departments.

TRIAL REGISTRATION

NCT00201474.

No association between APOE and major depressive disorder in a community sample of 17,507 adults

Mood-related phenotypes are commonly comorbid with, and have been implicated in the development of, neurological disorders. APOE is a major susceptibility gene for neurodegeneration. Recent evidence from case-control studies has suggested that the apoE 2 allele is associated with major depressive disorder (MDD). However, evidence from large-scale community-based studies is limited. APOE was genotyped for 17,507 men and women, aged 41-80 years, participating in the European Prospective Investigation into Cancer-Norfolk study, who had also completed a psychosocial assessment that included measures of emotional health status defined by MDD, psychological distress (as represented by the Mental Health Inventory, MHI-5), and by an assessment of neuroticism. No associations were found between APOE genotypes and measures either of past-year or lifetime MDD, or of emotional health defined according to the MHI-5 or by neuroticism. Data from this large-scale, community-based, study are not supportive of an association between either MDD or associated measures of emotional state and APOE genotype. These findings suggest that the association between APOE and MDD risk is more modest than has been previously reported.

Remodeling of hippocampal spine synapses in the rat learned helplessness model of depression

BACKGROUND

Although it has been postulated for many years that depression is associated with loss of synapses, primarily in the hippocampus, and that antidepressants facilitate synapse growth, we still lack ultrastructural evidence that changes in depressive behavior are indeed correlated with structural synaptic modifications.

METHODS

We analyzed hippocampal spine synapses of male rats (n=127) with electron microscopic stereology in association with performance in the learned helplessness paradigm.

RESULTS

Inescapable footshock (IES) caused an acute and persistent loss of spine synapses in each of CA1, CA3, and dentate gyrus, which was associated with a severe escape deficit in learned helplessness. On the other hand, IES elicited no significant synaptic alterations in motor cortex. A single injection of corticosterone reproduced both the hippocampal synaptic changes and the behavioral responses induced by IES. Treatment of IES-exposed animals for 6 days with desipramine reversed both the hippocampal spine synapse loss and the escape deficit in learned helplessness. We noted, however, that desipramine failed to restore the number of CA1 spine synapses to nonstressed levels, which was associated with a minor escape deficit compared with nonstressed control rats. Shorter, 1-day or 3-day desipramine treatments, however, had neither synaptic nor behavioral effects.

CONCLUSIONS

These results indicate that changes in depressive behavior are associated with remarkable remodeling of hippocampal spine synapses at the ultrastructural level. Because spine synapse loss contributes to hippocampal dysfunction, this cellular mechanism may be an important component in the neurobiology of stress-related disorders such as depression.

Stress, anxiety, depression, and epilepsy: investigating the relationship between psychological factors and seizures

OBJECTIVE

The goal of the study described here was to examine the interrelationship between psychological factors (anxiety, stress, and depression) and seizures.

METHODS

In this longitudinal cohort study, data on anxiety, depression, perceived stress, and seizure recency (time since last seizure) and frequency were collected at two time points using standard validated questionnaire measures. Empirically based models with psychological factors explaining change in (1) seizure recency and (2) seizure frequency scores across time were specified. We then tested how these psychological factors acted together in predicting seizure recency and frequency. Our data were used to test whether these models were valid for the study population. Latent variable structural equation modeling was used for the analysis.

RESULTS

Four hundred thirty-three of the 558 individuals who initially consented to participate provided two waves of data for this analysis. Stress (beta=0.25, P<0.01), anxiety (beta=0.30, P<0.01), and depression (beta=0.30, P<0.01) all predicted change in seizure recency. However, it was depression that mediated the relationship of both anxiety and stress with modeled change in seizure recency (beta=0.19, P<0.01) and seizure frequency (beta=0.30, P<0.01) over time.

CONCLUSION

Depression mediates the relationship between stress and anxiety and change in seizure recency and seizure frequency. These findings highlight the importance of depression management in addition to seizure management in the assessment and treatment of epilepsy in an adult population.

Negative affect predicts subsequent cognitive change in multiple sclerosis

Baseline predictors of cognitive change were explored in a sample of persons with multiple sclerosis (MS). Potential predictors included demographic features, baseline clinical characteristics, and psychological state. Participants were 38 individuals diagnosed with either relapsing remitting or secondary progressive MS who did not meet criteria for a current major depressive episode. Subjects were tested at baseline and approximately 1 year in an ongoing longitudinal study of cognition in MS. Participants completed neuropsychological tests sensitive to impairment in MS. They also completed self-report measures of depression, anxiety, fatigue, apathy, and positive and negative affect. Baseline measures of negative affect (e.g., depressed mood, state anxiety, and negative affective state) consistently predicted cognitive change over the course of the study. Higher baseline levels of negative affect were associated with greater relative declines in cognitive performance. This longitudinal relation occurred in the absence of a cross-sectional relation between negative affect and overall cognition. High baseline negative affect particularly predicted a relative decline in episodic memory for newly learned verbal and visuospatial information. The negative affect measures were unique in their predictive value among all the baseline measures assessed. (JINS, 2009, 15, 53-61.).

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.

Depressive Störungen

Das Spektrum depressiver Erkrankungen macht den Hauptteil affektiver Störungen aus und gehört mit einer Inzidenz von ca. 8–20% zu den häufigsten psychischen Erkrankungen. Depressionen werden nach wie vor zu selten einer adäquaten Therapie (Antidepressiva, störungsspezifische Psychotherapie wie z. B. kognitive Verhaltenstherapie) zugeführt.

Depressive disorders and anti-parkinson drug treatment: a case register study

OBJECTIVE

To estimate the rate of treatment with anti-parkinson drugs (APD) among patients with depression.

METHOD

In a nationwide case register linkage study, all persons with a main diagnosis of depression during 5 years were identified. A control group of persons with diagnoses of osteoarthritis was included. The subsequent risk of getting treatment with APD was estimated for the two groups. Statistical analyses involved Poisson's regression and competing risk models.

RESULTS

A total of 14 991 persons were included. The rate of getting APD was 2.57 (95% CI: 1.46-4.52) times higher for persons with depression than for persons with osteoarthritis. Overall, the rate was highest for men. However, women with depression had a 3.89 (95% CI: 1.98-7.62) times higher rate of APD treatment as women with osteoarthritis while no significant difference was found among men.

CONCLUSION

Provided that prescription of APD reflects the presence of Parkinson's disease, results support a positive statistical association between depressive disorders and Parkinson's disease.

Treatment with antidepressants and lithium is associated with increased risk of treatment with antiparkinson drugs: a pharmacoepidemiological study

OBJECTIVE

To estimate the risk for persons treated with antidepressants or lithium of subsequent treatment with antiparkinson drugs (APD).

METHODS

The Danish national prescription database supplied data on all persons who received antidepressants, lithium, or antidiabetics (first control group). A second control group was included comprising persons from the general population. Outcome was purchase of APD and the study period was 1995 to 1999.

RESULTS

In total, 1 293 789 persons were included. The rate ratio of treatment with APD after treatment with antidepressants was 2.27 (95% CI 2.14 to 2.42) for men and 1.50 (95% CI 1.43 to 1.58) for women. Figures for lithium were almost identical.

CONCLUSION

Persons treated with antidepressants or lithium are at increased risk of subsequently treatment with APD, showing an association between anxiety/affective disorder and Parkinson's disease.