Specifying the Neuropsychology of Affective Disorders: Clinical, Demographic and Neurobiological Factors

A review on the impact of cognitive dysfunction on social, occupational, and general functional outcomes in bipolar disorder

OBJECTIVES

Bipolar disorder (BD) is associated with significant impairment in cognitive performance across multiple domains of function that often persist after clinical recovery. It remains unclear, however, as to whether this process is related to the clinical status of BD being depressed, manic/hypomanic, or euthymic. In this review, we examine the literature on the cross-sectional and longitudinal relationships between cognitive function and general function depending on the clinical phase of BD.

METHODS

A systematic review of original research that studied both cognitive function and general function in adults (18-60 years), restricted to BD, was conducted in a total of 18 studies meeting inclusion/exclusion criteria.

RESULTS

Results show cross-sectional and prospective relationships between cognitive function and general function in patients with BD in both symptomatic and euthymic patients with BD. While studies using general measures of function (e.g., Global Assessment of Function scale) show more inconsistent associations with cognitive function, those employing assessments of domain specific function, suggest a consistent relationship between social and occupational function and cognitive performance. Executive function is commonly affected by cognitive deficits in these patients, but in addition a variety of domains show associations with functional outcomes (e.g., social function, occupational function). Notably, the emerging evidence suggests that cognitive function may be a better predictor of future general function than affective symptom severity.

CONCLUSIONS

Despite some inconsistencies, in sum the literature on the relationship between cognitive function and general function in BD implicates both cross-sectional and longitudinal associations, both in symptomatic and euthymic patients with BD. And in terms of capturing these changes functional scales in particular domain-specific measures seem superior to general measures.

Influence of Pharmacotherapy on Cognitive Functions in Depression: A Review of the Literature

In addition to irregularities relating to the emotional sphere, the cognitive impairment in depression is a part of the clinical picture of this affective disorder. Some of the cognitive deficits may be associated with the severity of psychopathological symptoms of depression, while others are more established and can also occur during periods of remission. The participation in cognitive functioning of people with depression have a number of factors: the severity of symptoms, concurrent anxiety disorders, gender, age, education, duration of the disease, and number of previous episodes, as well as general somatic health or medication used. The pharmacological treatment may have varying impact on the different areas of cognition. Research on pharmacotherapy for depression and its impact on cognitive functioning continue and are very popular among clinicians and researchers. The relationship between antidepressants and cognitive abilities is always modulated by the type of depressive disorder, neurobiological factors, and demographic variables. This article presents a review of the studies relating to assessment of the effects of various antidepressants on cognitive abilities among patients with depression.

Midlife Eriksonian psychosocial development: Setting the stage for late-life cognitive and emotional health

Erikson's (1950) model of adult psychosocial development outlines the significance of successful involvement within one's relationships, work, and community for healthy aging. He theorized that the consequences of not meeting developmental challenges included stagnation and emotional despair. Drawing on this model, the present study uses prospective longitudinal data to examine how the quality of assessed Eriksonian psychosocial development in midlife relates to late-life cognitive and emotional functioning. In particular we were interested to see whether late-life depression mediated the relationship between Eriksonian development and specific domains of cognitive functioning (i.e., executive functioning and memory). Participants were 159 men from the over-75 year longitudinal Study of Adult Development. The sample was comprised of men from both higher and lower socioeconomic strata. Eriksonian psychosocial development was coded from men's narrative responses to interviews between the ages of 30-47 (Vaillant & Milofsky, 1980). In late life (ages 75-85) men completed a performance-based neuropsychological assessment measuring global cognitive status, executive functioning, and memory. In addition depressive symptomatology was assessed using the Geriatric Depression Scale. Our results indicated that higher midlife Eriksonian psychosocial development was associated with stronger global cognitive functioning and executive functioning, and lower levels of depression 3 to 4 decades later. There was no significant association between Eriksonian development and late-life memory. Late-life depression mediated the relationship between Eriksonian development and both global cognition and executive functioning. All of these results controlled for highest level of education and adolescent intelligence. Findings have important implications for understanding the lasting benefits of psychosocial engagement in mid-adulthood for late-life cognitive and emotional health. In addition, it may be that less successful psychosocial development increases levels of depression making individuals more vulnerable to specific areas of cognitive decline.

Does depression matter in neuropsychological performances in anorexia nervosa? A descriptive review

OBJECTIVE

This review aims to examine the impact of depressive symptoms on the assessment of cognitive flexibility, central coherence, and decision-making in individuals with anorexia nervosa (AN).

METHOD

An online search was carried out using PubMed and PsycInfo. Articles were selected for review if they were published in English between 1990 and 2014 and used the Wisconsin Card Sorting Test, the Trail Making Task parts A and B, the Brixton Test, the Rey-Osterrieth Complex Figure Test, and/or the Iowa Gambling Task.

RESULTS

Sixty-two studies were included. Thirty (48%) of the studies statistically assessed the association between depression and neurocognition in AN versus healthy controls. Where significant correlations were found, it became clear that the more serious the depression, the greater the neuropsychological impairment. Only six (10%) studies examined whether increased depressive symptoms were able to eliminate the differences between individuals with AN and healthy controls, and one study found that depressive symptoms did eliminate group differences in cognitive flexibility and decision-making.

DISCUSSION

Only a subgroup of articles on neuropsychology in AN adjusted for depression. However, given the role of depression that some articles suggest, future studies should pay closer attention to the evaluation of this potential confounder.

Nice or effective? Social problem solving strategies in patients with major depressive disorder

Our study addressed distinct aspects of social problem solving in 28 hospitalized patients with Major Depressive Disorder (MDD) and 28 matched healthy controls. Three scenario-based tests assessed the ability to infer the mental states of story characters in difficult interpersonal situations, the capacity to freely generate good strategies for dealing with such situations and the ability to identify the best solutions among less optimal alternatives. Also, standard tests assessing attention, memory, executive function and trait empathy were administered. Compared to controls, MDD patients showed impaired interpretation of other peoples' sarcastic remarks but not of the mental states underlying other peoples' actions. Furthermore, MDD patients generated fewer strategies that were socially sensitive and practically effective at the same time or at least only socially sensitive. Overall, while the free generation of adequate strategies for difficult social situations was impaired, recognition of optimal solutions among alternatives was spared in MDD patients. Higher generation scores were associated with higher trait empathy and cognitive flexibility scores. We suggest that this specific pattern of impairments ought to be considered in the development of therapies addressing impaired social skills in MDD.

Rumination in bipolar disorder: a systematic review

OBJECTIVE

To conduct a systematic review of the literature about the symptom of rumination in bipolar disorder (BD).

METHODS

We searched the MEDLINE (PubMed), ISI Web of Knowledge, PsycINFO, and SciELO databases using the descriptors "rumination" and "bipolar disorder" and no time limits. This strategy yielded 105 references, of which 74 were selected. Inclusion criteria were studies involving patients with BD and the use of at least one validated scale for the assessment of rumination. Review articles were excluded. Seventeen articles were ultimately analyzed and included in the review.

RESULTS

Rumination is present in all BD phases, is a stable interepisodic symptom, is associated with symptoms of depression, anxiety, and hypomania, and may occur in response to both positive and negative affect. There is no research on rumination and neurobiological findings in patients with BD.

CONCLUSIONS

Rumination seems to be independent of mood state, but shows close relationship with it. It is possible that rumination has a negative impact on cognitive and executive functions, particularly inhibitory control. Finally, rumination is an important symptom in both phases of BD, and, therefore, may be a useful target for further exploration as a dimensional domain and a transdiagnostic phenomenon in Research Domain Criteria (RDoC) projects.

Shared dimensions of performance and activation dysfunction in cognitive control in females with mood disorders

Major depressive disorder and bipolar disorder share symptoms that may reflect core mood disorder features. This has led to the pursuit of intermediate phenotypes and a dimensional approach to understand neurobiological disruptions in mood disorders. Executive dysfunction, including cognitive control, may represent a promising intermediate phenotype across major depressive disorder and bipolar disorder. This study examined dimensions of cognitive control in women with major depressive disorder or bipolar disorder in comparison to healthy control subjects using two separate, consecutive experiments. For Experiment 1, participants completed a behavioural cognitive control task (healthy controls = 150, major depressive disorder = 260, bipolar disorder = 202; age range 17-84 years). A sample of those participants (healthy controls = 17, major depressive disorder = 19, and bipolar disorder = 16) completed a similar cognitive control task in an event-related design functional magnetic resonance imaging protocol for Experiment 2. Results for Experiment 1 showed greater impairments on the cognitive control task in patients with mood disorders relative to healthy controls (P < 0.001), with more of those in the mood disorder group falling into the 'impaired' range when using clinical cut-offs (<5th percentile). Experiment 2 revealed only a few areas of shared activation differences in mood disorder greater than healthy controls. Activation analyses using performance as a regressor, irrespective of diagnosis, revealed within and extra-network areas that were more active in poor performers. In summary, performance and activation during cognitive control tasks may represent an intermediate phenotype for mood disorders. However, cognitive control dysfunction is not uniform across women with mood disorders, and activation is linked to performance more so than disease. These findings support subtype and dimensional approaches to understanding risk and expression of mood disorders and are a promising area of inquiry, in line with the Research Domain Criteria initiative of NIMH.

Cognitive functioning after deep brain stimulation in subcallosal cingulate gyrus for treatment-resistant depression: an exploratory study

Deep brain stimulation (DBS) is being investigated as a therapeutic alternative for patients with treatment-resistant depression (TRD), but its cognitive safety has been scarcely explored. The aim of this exploratory study is to evaluate cognitive function of patients before and after deep brain stimulation of the subgenual cingulate gyrus (SCG). Eight treatment-resistant depressed patients were implanted in subgenual cingulate gyrus. A neuropsychological battery was used to evaluate patients before surgery and 1-year after. A matched group of eight first-episode patients was also assessed. A MANOVA was performed for each cognitive domain and those tests showing main time effects were then correlated with depressive symptoms and with medication load. There were significant group and time effects for memory and a group effect for language. No significant interactions between groups or cognitive domains were observed. Medication load was negatively correlated with memory at time 1, and clinical change negatively correlated with memory improvement. These findings support the cognitive safety of DBS of subgenual cingulate gyrus, as cognitive function did not worsen after chronic stimulation and memory performance even improved. The results, though, should be interpreted cautiously given the small sample size and the fact that some treatment-resistant patients received electroconvulsive therapy (ECT) before implantation.

Pharmacological and non-pharmacological interventions to improve cognitive dysfunction and functional ability in clinical depression--a systematic review

Cognitive dysfunction is of clinical significance and exerts longstanding implication on patients׳ function. Pharmacological and non-pharmacological treatments of cognitive dysfunction are emerging. This review evaluates pharmacological and non-pharmacological treatments of cognitive impairment primarily in the domains of memory, attention, processing speed and executive function in clinical depression. A total of 35 studies were retrieved from Pubmed, PsycInfo and Scopus after applying inclusion and exclusion criteria. Results show that various classes of antidepressants exert improving effects on cognitive function across several cognitive domains. Specifically, studies suggest that SSRIs, the SSRE tianeptine, the SNRI duloxetine, vortioxetine and other antidepressants such as bupropion and moclobemide may exert certain improving effects on cognitive function in depression, such as in learning and memory and executive function. Class-specific cognitive domains or specific dose-response relationships were not identified yet. The few non-pharmacological studies conducted employing cognitive orientated treatments and cognitive remediation therapy show promising results for the improvement of cognitive impairment in depression. However, several methodological constraints of studies limit generalizability of the results and caution the interpretation. Future direction should consider the development of a neuropsychological consensus cognitive battery to support the discovery, clinical assessment, comparison of studies and registration of new agents in clinical depression.

Neuropsychological functioning in adolescents and young adults with major depressive disorder--a review

While neuropsychological dysfunction is a contributor to major depressive disorder (MDD) in adult MDD, little is known about neuropsychological function in MDD during adolescence and early adulthood. The aim of this review is to evaluate literature on neuropsychological function in this young age group. A database search of Medline, the Cochrane database and PsycInfo was conducted. Inclusion/exclusion criteria yielded seven case-control studies on neuropsychological functioning in MDD (12-25 years of age) published since 1995. Effect sizes were calculated. Results show a broader range of statistically significant neuropsychological deficits in MDD compared to controls in the cognitive domains of executive function (EF), working memory (WM), psychomotor and processing speed (PPS), verbal fluency (VF) and visual (-spatial) memory (VM). Most convincingly, three out of four studies investigating WM and three out of four studies investigating PPS found statistically significant impairments in MDD with varying effect sizes. EF deficits were reported only in three out of seven studies with small, medium and large effect sizes. While some evidence was found for impaired VM and VF, no evidence was observed for attention and verbal learning and memory; however, these domains have been less extensively studied. Further research is required to broaden the study base.

Investigating biases of attention and memory for alcohol-related and negative words in alcohol-dependents with and without major depression after day-clinic treatment

This study aimed to investigate attentional and memory biases in alcohol-dependents with and without major depression compared to healthy controls. We assumed that both groups of alcohol-dependents would show attentional and memory biases for alcohol-related words. For the alcohol-dependents with depression, we additionally expected both types of biases for negative words. Alcohol-dependents without co-morbidity (Alc) and alcohol-dependents with major depression (D-Alc) as well as control participants with a moderate consumption of alcohol (Con) completed an alcohol Stroop task and a directed forgetting paradigm using word stimuli from three categories: neutral, negative, and alcohol-related. Stroop effects showed that not only alcohol-dependents but also control participants were more distracted by alcohol-related than by negative words. In the directed forgetting procedure, all participants showed a significant effect for each word-category, including alcohol-related and negative words. The D-Alc-group memorized more alcohol-related than negative to-be-remembered words. The results do not corroborate the hypothesis of more pronounced attentional and memory biases in alcohol-dependents. However, in alcohol-dependents with depression a memory bias for alcohol-related material was found, suggesting that this group may be more pre-occupied with alcohol than patients without such co-morbidity.

Advancing biomarker research: utilizing 'Big Data' approaches for the characterization and prevention of bipolar disorder

OBJECTIVE

To provide a strategic framework for the prevention of bipolar disorder (BD) that incorporates a 'Big Data' approach to risk assessment for BD.

METHODS

Computerized databases (e.g., Pubmed, PsychInfo, and MedlinePlus) were used to access English-language articles published between 1966 and 2012 with the search terms bipolar disorder, prodrome, 'Big Data', and biomarkers cross-referenced with genomics/genetics, transcriptomics, proteomics, metabolomics, inflammation, oxidative stress, neurotrophic factors, cytokines, cognition, neurocognition, and neuroimaging. Papers were selected from the initial search if the primary outcome(s) of interest was (were) categorized in any of the following domains: (i) 'omics' (e.g., genomics), (ii) molecular, (iii) neuroimaging, and (iv) neurocognitive.

RESULTS

The current strategic approach to identifying individuals at risk for BD, with an emphasis on phenotypic information and family history, has insufficient predictive validity and is clinically inadequate. The heterogeneous clinical presentation of BD, as well as its pathoetiological complexity, suggests that it is unlikely that a single biomarker (or an exclusive biomarker approach) will sufficiently augment currently inadequate phenotypic-centric prediction models. We propose a 'Big Data'- bioinformatics approach that integrates vast and complex phenotypic, anamnestic, behavioral, family, and personal 'omics' profiling. Bioinformatic processing approaches, utilizing cloud- and grid-enabled computing, are now capable of analyzing data on the order of tera-, peta-, and exabytes, providing hitherto unheard of opportunities to fundamentally revolutionize how psychiatric disorders are predicted, prevented, and treated. High-throughput networks dedicated to research on, and the treatment of, BD, integrating both adult and younger populations, will be essential to sufficiently enroll adequate samples of individuals across the neurodevelopmental trajectory in studies to enable the characterization and prevention of this heterogeneous disorder.

CONCLUSIONS

Advances in bioinformatics using a 'Big Data' approach provide an opportunity for novel insights regarding the pathoetiology of BD. The coordinated integration of research centers, inclusive of mixed-age populations, is a promising strategic direction for advancing this line of neuropsychiatric research.

Verbal learning on depressive pseudodementia: accentuate impairment of free recall, moderate on learning processes, and spared short-term and recognition memory

OBJECTIVE

Depressive pseudodementia (DPD) is a clinical condition characterized by depressive symptoms followed by cognitive and functional impairment characteristics of dementia. Memory complaints are one of the most related cognitive symptoms in DPD. The present study aims to assess the verbal learning profile of elderly patients with DPD.

METHODS

Ninety-six older adults (34 DPD and 62 controls) were assessed by neuropsychological tests including the Rey auditory-verbal learning test (RAVLT). A multivariate general linear model was used to assess group differences and controlled for demographic factors.

RESULTS

Moderate or large effects were found on all RAVLT components, except for short-term and recognition memory.

CONCLUSION

DPD impairs verbal memory, with large effect size on free recall and moderate effect size on the learning. Short-term storage and recognition memory are useful in clinical contexts when the differential diagnosis is required.

Effects of acute cortisol administration on response inhibition in patients with major depression and healthy controls

Glucocorticoids (GCs) have repeatedly been shown to impair hippocampus-mediated, declarative memory retrieval and prefrontal cortex-based working memory in healthy subjects. However, recent experimental studies indicated that patients with major depressive disorder (MDD) lack these impairing effects. These missing effects have been suggested to result from dysfunctional brain GC receptors. The purpose of the present study was to investigate whether response inhibition, an executive function relying on the integrity of the prefrontal cortex, would be impaired after cortisol administration in patients with MDD. In a placebo-controlled, double blind crossover study, 50 inpatients with MDD and 54 healthy control participants conducted an emotional go/no-go task consisting of human face stimuli (fearful, happy, and neutral) after receiving a dose of 10 mg hydrocortisone and after placebo. GC administration had an enhancing effect on inhibitory performance in healthy control participants, indicated by faster responses, while no GC effect was revealed for the patients group. Moreover, patients showed an overall worse performance than healthy participants. In conclusion, this study further supports the hypothesis of impaired central glucocorticoid receptor function in MDD patients. Regarding the importance of inhibitory functioning for daily living, further studies are needed to examine the impact of glucocorticoids on response inhibition.

Physical aggression, diagnostic presentation, and executive functioning in inpatient adolescents diagnosed with mood disorders

While a relationship has been identified between physical aggression and executive functioning within the adult population, this relationship has not yet been consistently examined in the adolescent population. This study examined the association between physical aggression towards others, self-reported depressive symptoms, and executive functioning within an adolescent inpatient sample diagnosed with a mood disorder. This study consisted of a retrospective chart review of 105 adolescent inpatients (ages 13-19) that received a diagnosis of a mood disorder (excluding Bipolar Disorder). Participants were grouped based on history of aggression towards others, resulting in a mood disorder with physically aggressive symptoms group (n = 49) and a mood disorder without physically aggressive symptoms group (n = 56). Ten scores on various measures of executive functioning were grouped into five executive functioning subdomains: Problem Solving/Planning, Cognitive Flexibility/Set Shifting, Response Inhibition/Interference Control, Fluency, and Working Memory/Simple Attention. Results from analyses of covariance indicated that there were no significant differences (p < .01) between aggression groups on any executive functioning subdomains. Correlation analyses (p < .01) indicated a negative correlation between disruptive behavior disorders and response inhibition/interference control, while anxiety disorders were negatively correlated with problem solving/planning. These findings provide important information regarding the presence of executive dysfunction in adolescent psychiatric conditions, and the specific executive subdomains that are implicated.

Is bipolar disorder an inflammatory condition? The relevance of microglial activation

PURPOSE OF REVIEW

Literature published over the past few years indicates that bipolar disorder has an inflammatory component but does not explicitly define bipolar disorder as an inflammatory or a noninflammatory condition.

RECENT FINDINGS

Recent studies have shown that bipolar disorder involves microglial activation and alterations in peripheral cytokines and have pointed to the efficacy of adjunctive anti-inflammatory therapies in bipolar depression.

SUMMARY

The presence of active microglia and increased proinflammatory cytokines in bipolar disorder suggests an important role of inflammatory components in the pathophysiology of the disease, as well as a possible link between neuroinflammation and peripheral toxicity.

Anhedonia and emotional word memory in patients with depression

Anhedonia is a key diagnostic criterion for major depression. Investigating the relation between the specific symptoms and emotional processing may help to understand the underlying cognitive mechanism of anhedonia in depression. In this study, we explored the potential association between memory for emotional words and anhedonia in 71 patients with depression and 61 healthy individuals. An emotional word-rating task was administered to assess self-reported emotional experience to words on both valence and arousal dimensions, and subsequent recall and recognition memory for these words. Depressed patients demonstrated a reduction in pleasure and arousal experience to positive words, but an increase in arousal experience to negative words. Depressed patients also displayed a lower overall memory performance in recall measure and a bias to memory of more negative words. Moreover, state anhedonia and trait anhedonia were associated with attenuated positive experience and enhanced negative experience in patients with depression only. Higher levels of anhedonia and depression severity were also associated with fewer positive words and more negative words memory. Patients with depression displayed a flat pattern of emotional experience to positive stimuli and a tendency towards rating negative stimuli more intensely.

Neuropsychological performance in a sample of 13-25 year olds with a history of non-psychotic major depressive disorder

BACKGROUND

There is evidence for neuropsychological dysfunction in depression among adult and elderly participants but little research has been conducted on the neuropsychological functioning of youth with depression. The aim of the present study was to investigate the neuropsychological functioning of outpatient young participants with depression.

METHODS

Computerised neuropsychological tests requiring executive functioning, working memory, attention, verbal memory and learning, planning, and visuospatial skills were carried out in a sample of 13-25year-olds with a lifetime history of non-psychotic major depression (n=32) and in healthy age balanced controls (n=65). Psychiatric diagnoses were ascertained using the MINI International Neuropsychiatric Interview.

RESULTS

Participants with current or previous major depressive disorder demonstrated impairments in executive function tasks requiring conceptual skills and set-shifting, attention and working memory. However, planning skills were found to be largely intact. Positive affect was associated to better attention, working memory and verbal learning in depressed participants, independently from gender and education.

LIMITATIONS

The results may be affected by the small sample size and heterogeneity of the sample.

CONCLUSION

The findings from this study indicate, and are one of the first to identify, that young subjects aged between 13 and 25, with a lifetime history of depression, have impaired executive and working memory functioning.

Remission of cognitive deficits in Parkinson's disease: recovery from a nonamnestic mild cognitive impairment or psychiatric symptoms remission?

Mild cognitive impairment is a clinical condition more frequent in patients with Parkinson's disease than in general population. The nonamnestic presentations, usually characterized by executive dysfunction, are most prevalent. We present a case report of a Parkinson's disease patient diagnosed with nonamnestic mild cognitive impairment that showed complete remission of cognitive symptoms after one year. We discuss the possible causes for the remission, focusing on the treatment of medical conditions such as a major depressive episode and vitamin B12 deficiency, in addition to the change of pharmacological treatment. In a third assessment, cognitive performance remained normal. The case report highlights the importance of controlling clinical comorbidities on the assessment and followup of mild cognitive impairment, especially on Parkinson's disease.

Tumor necrosis factor gene variation predicts hippocampus volume in healthy individuals

BACKGROUND

Cytokines such as tumor necrosis factor (TNF) α have been implicated in neurodegeneration relevant to various neuropsychiatric disorders. Little is known about the genetic predisposition to neurodegenerative properties of cytokine genes on brain function and on hippocampus (HC) function in particular. In this study we investigate the neurodegenerative role of TNF polymorphisms on brain morphology in healthy individuals.

METHODS

Voxel-based morphometry was used in a large sample of healthy individuals (n = 303) to analyze the associations between genetic variants of TNF (rs1800629; rs361525) and brain morphology (gray matter concentration).

RESULTS

In a region of interest analysis of the HC, for rs1800629, we observed a strong genotype effect on bilateral HC gray matter concentration. Carriers of one or two A-alleles had significantly smaller volumes compared with GG-homozygotes. For rs361525, a similar effect was observed at almost the same location, with the A-allele resulting in smaller HC volumes compared with GG homozygotes.

CONCLUSIONS

The findings suggest a neurodegenerative role of the A-alleles of the TNF single nucleotide polymorphisms rs1800629 (-308G/A) and rs361525 (-238G/A) on hippocampal volumes in healthy individuals. Future imaging studies on the role of these single nucleotide polymorphisms in psychiatric populations of diseases with neurodegenerative components are warranted.

Interleukin-6 gene (IL-6): a possible role in brain morphology in the healthy adult brain

Background

Cytokines such as interleukin 6 (IL-6) have been implicated in dual functions in neuropsychiatric disorders. Little is known about the genetic predisposition to neurodegenerative and neuroproliferative properties of cytokine genes. In this study the potential dual role of several IL-6 polymorphisms in brain morphology is investigated.

Methodology

In a large sample of healthy individuals (N = 303), associations between genetic variants of IL-6 (rs1800795; rs1800796, rs2069833, rs2069840) and brain volume (gray matter volume) were analyzed using voxel-based morphometry (VBM). Selection of single nucleotide polymorphisms (SNPs) followed a tagging SNP approach (e.g., Stampa algorigthm), yielding a capture 97.08% of the variation in the IL-6 gene using four tagging SNPs.

Principal findings/results

In a whole-brain analysis, the polymorphism rs1800795 (−174 C/G) showed a strong main effect of genotype (43 CC vs. 150 CG vs. 100 GG; x = 24, y = −10, z = −15; F(2,286) = 8.54, p_uncorrected = 0.0002; p_{AlphaSim-corrected} = 0.002; cluster size k = 577) within the right hippocampus head. Homozygous carriers of the G-allele had significantly larger hippocampus gray matter volumes compared to heterozygous subjects. None of the other investigated SNPs showed a significant association with grey matter volume in whole-brain analyses.

Conclusions/significance

These findings suggest a possible neuroprotective role of the G-allele of the SNP rs1800795 on hippocampal volumes. Studies on the role of this SNP in psychiatric populations and especially in those with an affected hippocampus (e.g., by maltreatment, stress) are warranted.

The effects of most commonly prescribed second generation antidepressants on driving ability: a systematic review : 70th Birthday Prof. Riederer

Driving a car is vital for the functional autonomy of patients to take part in activities of daily living. Both psychopathologic symptoms and psychopharmacologic treatment may impair driving ability. This article provides a systematic review of published studies (1980-2011) on commonly prescribed newer antidepressants and driving performance. A total of 21 studies could be included in the review, indicating that there is a lack of controlled patient studies. Investigations on newer antidepressants were frequently undertaken in healthy subjects focusing on acute or subchronic effects of application, predominately in young male participants, with dosages usually given in an ambulatory setting. No data, according to selection criteria, were found with respect to agomelatine, duloxetine, bupropion and viloxazine. There is evidence that the SSRIs (citalopram, escitalopram, fluoxetine, fluvoxamine, sertraline, paroxetine) and the SNRI venlafaxine have no deleterious effects on driving ability. Acute use of mirtazapine does produce impairments that diminish to some degree when given as a nocturnal dose and cannot be seen after repeated dosing in healthy controls. Patients obviously benefit from treatment with newer antidepressants; however, at least a subgroup does not reach performance level of healthy subjects. More patient studies are needed that elaborate specific relationships between clinical subtypes of the illness and response to different antidepressants, considering course and duration of illness, co-morbidities and not least neuropsychological and neurobiological characteristics.