Differential patterns of psychomotor functioning in unmedicated melancholic and nonmelancholic depressed patients

Linking inter-subject variability of cerebellar functional connectome to clinical symptoms in major depressive disorder

Major depressive disorder (MDD) is a highly prevalent psychiatric disorder with remarkable inter-subject variability in clinical manifestations. Neuroimaging changes of the cerebellum have been recently proposed as a way to characterize MDD-related brain disruptions and might further explain various clinical symptoms. However, the cerebellar contributions to MDD clinical heterogeneity remain largely unknown. The analyzed data consisted of 251 MDD patients and 235 matching healthy controls (HC). The inter-subject variability of functional connectomes (IVFC) was estimated via Pearson's correlation analysis between each pair of the cerebellar and cerebral regions based on resting-state functional magnetic resonance imaging (rs-fMRI). A partial least squares (PLS) regression analysis was performed to determine the potential dimension linking the IVFC to clinical symptom measures. The results indicated that similar spatial distribution patterns of the cerebellar IVFC were observed between MDD and HC, but the MDD group exhibited abnormal IVFC alterations in the bilateral Cerebelum_4_5, bilateral Cerebelum_6, Vermis_1_2 and Vermis_8. The PLS model revealed that the IVFC pattern in the left Cerebelum_6 was significantly associated with three HAMD-17 items including the work and activities, psychomotor retardation, and depressed mood. These findings provided new evidence for the cerebellar changes in MDD. Specifically, we found that the altered inter-subject variability measurements correlated with clinical manifestations of this illness. Elucidating this variability could prove helpful for the evaluation of MDD heterogeneity as well as for understanding its pathophysiological mechanism.

Processing speed and sustained attention in bipolar disorder and major depressive disorder: A systematic review and meta-analysis

OBJECTIVES

Cognitive impairment is a core feature of bipolar disorder (BD) and major depressive disorder (MDD). Deficits in processing speed (PS) and sustained attention (SA) may be particularly impaired and may underpin a broader profile of deficits, however current knowledge of the nature of these impairments is limited by heterogeneous results in the literature. Few reviews to date have attempted to disentangle sources of heterogeneity to assess the presence and magnitude of impairments in PS and SA in BD and MDD.

METHODS

One hundred and three studies were reviewed to examine performance in tests of PS and SA in BD (n = 3452) and MDD (n = 5461) compared to healthy controls (n = 8016). Neuropsychological methodology used in the literature was summarised. Data were meta-analysed to assess impairments in PS and SA for each neuropsychological test separately. Subgroup analysis was performed across mood states to investigate sources of heterogeneity.

RESULTS

Impairments were found across most neuropsychological tests, with small to large effect sizes for BD (range: d = 0.19-0.96) and MDD (range: d = 0.29-0.86). Impairments were present in symptomatic states and euthymia in most cases. Some outcome measures were not impaired in euthymia. Heterogeneity was observed for most neuropsychological tests and remained after separating by mood state. There inadequate data to meta-analyse some outcome measures, particularly for symptomatic groups.

CONCLUSION

Impairments in PS and SA in BD and MDD can be observed across most neuropsychological tests. Future research should further investigate the nature of these impairments across mood states, controlling for clinical confounds.

Limited time-specific and longitudinal effects of depressive and manic symptoms on cognition in bipolar spectrum disorders

OBJECTIVES

Previous research suggests that cognitive performance worsens during manic and depressed states in bipolar disorder (BD). However, studies have often relied upon between-subject, cross-sectional analyses and smaller sample sizes. The current study examined the relationship between mood symptoms and cognition in a within-subject, longitudinal study with a large sample.

METHODS

Seven hundred and seventy-three individuals with BD completed a neuropsychological battery and mood assessments at baseline and 1-year follow-up. The battery captured eight domains of cognition: fine motor dexterity, visual memory, auditory memory, emotion processing, and four aspects of executive functioning: verbal fluency and processing speed; conceptual reasoning and set shifting; processing speed with influence resolution; and inhibitory control. Structural equation modeling was conducted to examine the cross-sectional and longitudinal relationships between depressive symptoms, manic symptoms, and cognitive performance. Age and education were included as covariates. Eight models were run with the respective cognitive domains.

RESULTS

Baseline mood positively predicted 1-year mood, and baseline cognition positively predicted 1-year cognition. Mood and cognition were generally not related for the eight cognitive domains. Baseline mania was predictive in one of eight baseline domains (conceptual reasoning and set shifting); baseline cognition predicted 1-year symptoms (inhibitory control-depression symptoms, visual memory-manic symptoms).

CONCLUSIONS

In a large community sample of patients with bipolar spectrum disorder, cognitive performance appears to be largely unrelated to depressive and manic symptoms, suggesting that cognitive dysfunction is stable in BD and is not dependent on mood state in BD. Future work could examine how treatment affects relationship between cognition and mood.

SIGNIFICANT OUTCOMES

Cognitive dysfunction appears to be largely independent of mood symptoms in bipolar disorder.

LIMITATIONS

The sample was generally highly educated (M = 15.22), the majority of the subsample with elevated manic symptoms generally presented with concurrent depressive elevated symptoms, and the study did not stratify recruitment based on mood state.

Psychomotor semiology in depression: a standardized clinical psychomotor approach

BACKGROUND

Although psychomotor symptoms are associated with the clinical symptomatology of depression, they are rarely assessed and standardized clinical evaluation tools are lacking. Psychomotor retardation is sometimes assessed through direct patient observations by clinicians or through a clinical observation grid, in the absence of a standardized psychomotor assessment. In this pilot study, we evaluated the feasibility of standardized psychomotor examination of patients with major depressive disorder (MDD) and detailed a psychomotor semiology in these patients.

METHODS

We used a standardized psychomotor assessment to examine 25 patients with MDD and 25 age- and sex-matched healthy controls (HC) and compared their psychomotor profiles. Using standardized tests, we assessed muscle tone and posture, gross motor skills, perceptual-motor skills, and body image/organization. Clinical assessments of depressive symptoms (levels of psychomotor retardation, anxiety, and self-esteem) comprised this detailed psychomotor examination.

RESULTS

All participants were examined using the standardized psychomotor assessment. The main results of the psychomotor examination highlighted low body image of MDD participants (p < 0.001). Significant differences between groups were found in passive muscle tone, posture, emotional control, jumping, manual dexterity, walking, and praxis. Among these psychomotor variables, body image, passivity, jumping and rhythm scores predicted an MDD diagnosis.

CONCLUSIONS

Beyond the psychomotor retardation known to be present in MDD patients, this examination revealed an entire psychomotor symptomatology characterized by elevated muscle tone, poor body image associated with poor self-esteem, slowness in global motor skills and manual praxis, and poor rhythmic adaptation. In light of these results, we encourage clinicians to consider using a standardized tool to conduct detailed psychomotor examination of patients with depressive disorders.

TRIAL REGISTRATION

ClinicalTrials.gov identifier: NCT04031937 , 24/07/2019.

Depression Severity Is Related to Less Gross Body Movement: A Motion Energy Analysis

Psychomotor retardation is a well-known clinical phenomenon in depressed patients that can be measured in various ways. This study aimed to investigate objectively measured gross body movement (GBM) during a semi-structured clinical interview in patients with a depressive disorder and its relation with depression severity. A total of 41 patients with a diagnosis of depressive disorder were assessed both with a clinician-rated interview (Hamilton Depression Rating Scale) and a self-rating questionnaire (Beck Depression Inventory-II) for depression severity. Motion energy analysis (MEA) was applied on videos of additional semi-structured clinical interviews. We considered (partial) correlations between patients' GBM and depression scales. There was a significant, moderate negative correlation between both measures for depression severity (total scores) and GBM during the diagnostic interview. However, there was no significant correlation between the respective items assessing motor symptoms in the clinician-rated and the patient-rated depression severity scale and GBM. Findings imply that neither clinician ratings nor self-ratings of psychomotor symptoms in depressed patients are correlated with objectively measured GBM. MEA thus offers a unique insight into the embodied symptoms of depression that are not available via patients' self-ratings or clinician ratings.

Evaluating the severity of depressive symptoms using upper body motion captured by RGB-depth sensors and machine learning in a clinical interview setting: A preliminary study

BACKGROUND

Mood disorders have long been known to affect motor function. While methods to objectively assess such symptoms have been used in experiments, those same methods have not yet been applied in clinical practice because the methods are time-consuming, labor-intensive, or invasive.

METHODS

We videotaped the upper body of each subject using a Red-Green-Blue-Depth (RGB-D) sensor during a clinical interview setting. We then examined the relationship between depressive symptoms and body motion by comparing the head motion of patients with major depressive disorders (MDD) and bipolar disorders (BD) to the motion of healthy controls (HC). Furthermore, we attempted to predict the severity of depressive symptoms by using machine learning.

RESULTS

A total of 47 participants (HC, n = 16; MDD, n = 17; BD, n = 14) participated in the study, contributing to 144 data sets. It was found that patients with depression move significantly slower compared to HC in the 5th percentile and 50th percentile of motion speed. In addition, Hamilton Depression Rating Scale (HAMD)-17 scores correlated with 5th percentile, 50th percentile, and mean speed of motion. Moreover, using machine learning, the presence and/or severity of depressive symptoms based on HAMD-17 scores were distinguished by a kappa coefficient of 0.37 to 0.43.

LIMITATIONS

Limitations include the small number of subjects, especially the number of severe cases and young people.

CONCLUSIONS

The RGB-D sensor captured some differences in upper body motion between depressed patients and controls. If much larger samples are accumulated, machine learning may be useful in identifying objective measures for depression in the future.

Cerebral blood flow responses during prosaccade and antisaccade preparation in major depression

While impairments in executive functions have been well established in major depressive disorder (MDD), specific deficits in proactive control have scarcely been studied so far. Proactive control refers to cognitive processes during anticipation of a behaviorally relevant event that facilitate readiness to react. In this study, cerebral blood flow responses were investigated in MDD patients during a precued antisaccade task requiring preparatory attention and proactive inhibition. Using functional transcranial Doppler sonography, blood flow velocities in the middle cerebral arteries of both hemispheres were recorded in 40 MDD patients and 40 healthy controls. In the task, a target appeared left or right of the fixation point 5 s after a cuing stimulus; subjects had to move their gaze to the target (prosaccade) or its mirror image position (antisaccade). Video-based eye-tracking was applied for ocular recording. A right dominant blood flow increase arose during prosaccade and antisaccade preparation, which was smaller in MDD patients than controls. Patients exhibited a higher error rate than controls for antisaccades but not prosaccades. The smaller blood flow response may reflect blunted anticipatory activation of the dorsolateral prefrontal and inferior parietal cortices in MDD. The patients' increased antisaccade error rate suggests deficient inhibitory control. The findings support the notion of impairments in proactive control in MDD, which are clinically relevant as they may contribute to the deficits in cognition and behavioral regulation that characterize the disorder.

Striatal Functional Connectivity Alterations After Two-Week Antidepressant Treatment Associated to Enduring Clinical Improvement in Major Depressive Disorder

Background: Only less than 40% of patients with Major depressive disorder (MDD) can achieve remission after several weeks of initial antidepressant treatment. Predicting whether the prescribed treatment is effective in the following course may help clinicians modify the treatment regimen in time, and reduce the staggering burden for patients and society. However, there are not yet reliable markers based on neurobiological change after a treatment regimen steadily applied, for predicting clinical treatment outcome. The striatal circuits often exhibit abnormality for MDD patients, and are implicated in antidepressant treatments. Methods: Nineteen first-episode drug-naive MDD patients (nine females, mean age was 30 years old) were recruited to undergo clinical symptom assessment and resting state fMRI scanning at baseline, after 2 and 8 weeks of treatment with duloxetine. A seed-based analysis was used to obtain functional connectivity (FC) maps of six sub-regions of the stratum, then we explored the relationship of 2-week changes of striatal FC with clinical symptom improvement after 8-week duloxetine treatment. Results: The results revealed that 2-week FC changes of the striatal cognitive and affective subdivisions with the frontoparietal regions positively correlated with 8-week symptom improvement. We also found that early FC changes between the striatal motor subdivision and the motor-related cortical regions negatively correlated with later symptom improvement. Conclusions: These findings suggest that change of the FC of the cortical-striatal circuits at the early stage of treatment is critical for later remission of MDD. Furthermore, the association between the FC change and symptom improvement may have significant implication for clinical practice to regard neural changes as reference for evaluating how antidepressant treatment works.

The utility of an RDoC motor domain to understand psychomotor symptoms in depression

Despite the clinical impact of motor symptoms such as agitation or retardation on the course of depression, these symptoms are poorly understood. Novel developments in the field of instrumentation and mobile devices allow for dimensional and continuous recording of motor behavior in various settings, particularly outside the laboratory. Likewise, the use of novel assessments enables to combine multimodal neuroimaging with behavioral measures in order to investigate the neural correlates of motor dysfunction in depression. The research domain criteria (RDoC) framework will soon include a motor domain that will provide a framework for studying motor dysfunction in mood disorders. In addition, new studies within this framework will allow investigators to study motor symptoms across different stages of depression as well as other psychiatric diagnoses. Finally, the introduction of the RDoC motor domain will help test how motor symptoms integrate with the original five RDoC domains (negative valence, positive valence, cognitive, social processes, and arousal/regulation).

Observer-rated retardation but not agitation corresponds to objective motor measures in depression

OBJECTIVE

To explore the correlations between observer ratings and instrumental parameters across domains of psychomotor functioning in depression.

METHOD

In total, 73 patients with major depressive disorder underwent extensive psychomotor and clinical testing. Psychomotor functioning was assessed with (i) an observer-rated scale (the CORE measure) and also objectively with (ii) 24-h actigraphy, and (iii) a fine motor drawing task.

RESULTS

Observer ratings of retardation correlated with instrumental assessments of fine and gross motor functioning. In contrast, observer ratings of agitation did not correlate with observer ratings of retardation or with the instrumental measures. These associations were partly influenced by age and, to a lesser extent, by depression severity.

CONCLUSION

Psychomotor disturbance is a complex concept with different manifestations in depressed patients. Although observer ratings of retardation correspond well with instrumental measures of the motor domains, objective measurement of agitation and other aspects of psychomotor disturbance require further research.

Distinguishing Subgroups Based on Psychomotor Functioning among Patients with Major Depressive Disorder

BACKGROUND

Retardation and agitation are symptoms of major depressive disorder (MDD), and their presence could play a role in determining clinically meaningful depressive subtypes such as nonmelancholic depression (NMD) and melancholic depression (MD). In this project, we explored whether three depression subgroups (NMD, MD with psychotic symptoms, and MD without psychotic symptoms) could be distinguished based on objective measures of psychomotor functioning.

METHODS

Sixty-nine patients with MDD underwent extensive clinical and psychomotor testing prior to treatment with electroconvulsive therapy. Psychomotor functioning was assessed subjectively using the Core Assessment of Psychomotor Change (CORE) and objectively by means of both 24-h actigraphy and performance on a fine motor drawing task.

RESULTS

The daytime activity levels measured by actigraphy were significantly lower (F = 7.1, p = 0.0004) in MD patients both with and without psychotic symptoms than in those with NMD. No objective psychomotor variable was able to distinguish between melancholic patients with and those without psychotic symptoms.

CONCLUSIONS

The depression subtypes NMD, MD with psychotic symptoms, and MD without psychotic symptoms are not marked by increasing psychomotor retardation, possibly because psychomotor disturbance in MD with psychotic symptoms often consists of agitation rather than retardation, or a mixture of the two. However, psychomotor functioning as measured by actigraphy can be used to distinguish between NMD patients and MD patients.

Functional connectivity of the left DLPFC to striatum predicts treatment response of depression to TMS

BACKGROUND

Repetitive transcranial magnetic stimulation (TMS) is a non-invasive, safe, and efficacious treatment for depression. TMS has been shown to normalize abnormal functional connectivity of cortico-cortical circuits in depression and baseline functional connectivity of these circuits predicts treatment response. Less is known about the relationship between functional connectivity of frontostriatal circuits and treatment response.

OBJECTIVE/HYPOTHESIS

We investigated whether baseline functional connectivity of distinct frontostriatal circuits predicted response to TMS.

METHODS

Resting-state fMRI (rsfMRI) was acquired in 27 currently depressed subjects with treatment resistant depression and 27 healthy controls. Depressed subjects were treated with 5 weeks of daily TMS over the left dorsolateral prefrontal cortex (DLPFC). The functional connectivity between limbic, executive, rostral motor, and caudal motor regions of frontal cortex and their corresponding striatal targets were determined at baseline using an existing atlas based on diffusion tensor imaging. TMS treatment response was measured by percent reduction in the 24-item Hamilton Depression Rating Scale (HAMD24). In an exploratory analysis, correlations were determined between baseline functional connectivity and TMS treatment response.

RESULTS

Seven cortical clusters belonging to the executive and rostral motor frontostriatal projections had reduced functional connectivity in depression compared to healthy controls. No frontostriatal projections showed increased functional connectivity in depression (voxel-wise p < 0.01, family-wise α < 0.01). Only baseline functional connectivity between the left DLPFC and the striatum predicted TMS response. Higher baseline functional connectivity correlated with greater reductions in HAMD₂₄ (Pearson's R = 0.58, p = 0.002).

CONCLUSION(S)

In an exploratory analysis, higher functional connectivity between the left DLPFC and striatum predicted better treatment response. Our findings suggest that the antidepressant mechanism of action of TMS may require connectivity from cortex proximal to the stimulation site to the striatum.

Is nonverbal behavior in patients and interviewers relevant to the assessment of depression and its recovery? A study with Dutch and Brazilian patients

Nonverbal behaviors exhibited by patients with depression in their interactions with others may reflect social maladjustment and depression maintenance. Investigations of associations between unipolar depression and both patients' and interviewers' behaviors have been scarce and restricted to European samples. This study examined whether nonverbal behavior in patients and their interviewers is associated with depression severity and recovery. Cultural differences were explored. Seventy-eight depressed outpatients (28 Brazilians, 50 Dutch) were evaluated before and after 8-week pharmacological treatment. Patients were videotaped during the Hamilton Depression Scale interview before treatment, and the Brazilians were also videotaped after treatment. Nonverbal behaviors (patients' speaking effort and interviewers' encouragement) were analyzed using a two-factor ethogram. Results revealed that speaking effort was associated with encouragement and both are not influenced by baseline depression severity. However, from before to after treatment, whereas encouragement remained unchanged, speaking effort increased among unrecovered patients. Speaking effort was associated with patients' culture: Brazilians exhibited higher speaking effort than Dutch. These findings highlight that whereas the supportive nonverbal behavior of the interviewer may be stable, the set of nonverbal behaviors composed by head movements, eye contact and gestures displayed by the patients during their speaking in clinical interviews reflects depression persistence after treatment.

Neuropsychological changes in melancholic and atypical depression: A systematic review

There is not a consensus as to whether neuropsychological profiling can distinguish depressive subtypes. We aimed to systematically review and critically analyse the literature on cognitive function in patients with melancholic and atypical depression. We searched in databases PubMed, SCOPUS, Web of Knowledge and PsycInfo for papers comparing the neuropsychological performance of melancholic patients (MEL) to non-melancholic depressive patients (NMEL), including atypical depressives, and healthy controls (HC). All studies were scrutinised to determine the main methodological characteristics and particularly possible sources of bias influencing the results reported, using the STROBE statement checklist. We also provide effect size of the results reported for contrasts between MEL; patients and NMEL patients. Seventeen studies were included; most of them demonstrated higher neuropsychological impairments of MEL patients compared to both NMEL patients and HC on tasks requiring memory, executive function, attention and reaction time. Detailed analysis of the methodologies used in the studies revealed significant variability especially regarding the participants' sociodemographic characteristics, clinical characteristics of patients and differences in neuropsychological assessment. These findings suggest that MEL may have a distinct and impaired cognitive performance compared to NMEL depressive patients on tasks involving verbal and visual memory, executive function, sustained attention and span, as well as psychomotor speed, this last especially when cognitive load is increased. Additional studies with adequate control of potentially confounding variables will help to clarify further differences in the neuropsychological functioning of depressive subtypes.

A meta-analysis of cognitive performance in melancholic versus non-melancholic unipolar depression

BACKGROUND

Recently there is increasing recognition of cognitive dysfunction as a core feature of Major Depressive Disorder (MDD). The goal of the current meta-analysis was to review and examine in detail the specific features of cognitive dysfunction in Melancholic (MEL) versus Non-Melancholic (NMEL) MDD.

METHODS

An electronic literature search was performed to find studies comparing cognitive performance in MEL versus NMEL. A meta-analysis of broad cognitive domains (processing speed, reasoning/problem solving, verbal learning, visual learning, attention/working memory) was conducted on all included studies (n=9). Sensitivity and meta-regression analyses were also conducted to detect possible effects of moderator variables (age, gender, education, symptom severity and presence of treatments).

RESULTS

MEL patients were older and more severly depressed than NMEL subjects. The MEL group was characterized by a worse cognitive performance in attention/working memory (ES=-0.31), visual learning (ES=-0.35) and reasoning/problem solving (ES=-0.46). No difference was detected in drug-free patients by sensitivity analyses. No effect was found for any of our moderators on the cognitive performance in MEL vs NMEL.

CONCLUSION

Our findings seem to support a moderate but specific effect of melancholic features in affecting the cognitive performance of MDD, in particular as regards visual learning and executive functions.

Cognitive Dysfunction in Major Depressive Disorder. A Translational Review in Animal Models of the Disease

Major Depressive Disorder (MDD) is the most common psychiatric disease, affecting millions of people worldwide. In addition to the well-defined depressive symptoms, patients suffering from MDD consistently complain about cognitive disturbances, significantly exacerbating the burden of this illness. Among cognitive symptoms, impairments in attention, working memory, learning and memory or executive functions are often reported. However, available data about the heterogeneity of MDD patients and magnitude of cognitive symptoms through the different phases of MDD remain difficult to summarize. Thus, the first part of this review briefly overviewed clinical studies, focusing on the cognitive dysfunctions depending on the MDD type. As animal models are essential translational tools for underpinning the mechanisms of cognitive deficits in MDD, the second part of this review synthetized preclinical studies observing cognitive deficits in different rodent models of anxiety/depression. For each cognitive domain, we determined whether deficits could be shared across models. Particularly, we established whether specific stress-related procedures or unspecific criteria (such as species, sex or age) could segregate common cognitive alteration across models. Finally, the role of adult hippocampal neurogenesis in rodents in cognitive dysfunctions during MDD state was also discussed.

Cognitive Deficits as a Mediator of Poor Occupational Function in Remitted Major Depressive Disorder Patients

Cognitive deficits in major depressive disorder (MDD) patients have been described in numerous studies. However, few reports have aimed to describe cognitive deficits in the remitted state of MDD and the mediational effect of cognitive deficits on occupational outcome. The aim of the current review is to synthesize the literature on the mediating and moderating effects of specific domains of cognition on occupational impairment among people with remitted MDD. In addition, predictors of cognitive deficits found to be vocationally important will be examined. Upon examination of the extant literature, attention, executive function and verbal memory are areas of consistent impairment in remitted MDD patients. Cognitive domains shown to have considerable impact on vocational functioning include deficits in memory, attention, learning and executive function. Factors that adversely affect cognitive function related to occupational accommodation include higher age, late age at onset, residual depressive symptoms, history of melancholic/psychotic depression, and physical/psychiatric comorbidity, whereas higher levels of education showed a protective effect against cognitive deficit. Cognitive deficits are a principal mediator of occupational impairment in remitted MDD patients. Therapeutic interventions specifically targeting cognitive deficits in MDD are needed, even in the remitted state, to improve functional recovery, especially in patients who have a higher risk of cognitive deficit.

Electrical mapping in bipolar disorder patients during the oddball paradigm

Bipolar disorder (BD) is characterized by an alternated occurrence between acute mania episodes and depression or remission moments. The objective of this study is to analyze the information processing changes in BP (Bipolar Patients) (euthymia, depression and mania) during the oddball paradigm, focusing on the P300 component, an electric potential of the cerebral cortex generated in response to external sensorial stimuli, which involves more complex neurophysiological processes related to stimulus interpretation. Twenty-eight bipolar disorder patients (BP) (17 women and 11 men with average age of 32.5, SD: 9.5) and eleven healthy controls (HC) (7 women and 4 men with average age of 29.78, SD: 6.89) were enrolled in this study. The bipolar patients were divided into 3 major groups (i.e., euthymic, depressive and maniac) according to the score on the Clinical Global Impression--Bipolar Version (CGI-BP). The subjects performed the oddball paradigm simultaneously to the EEG record. EEG data were also recorded before and after the execution of the task. A one-way ANOVA was applied to compare the P300 component among the groups. After observing P300 and the subcomponents P3a and P3b, a similarity of amplitude and latency between euthymic and depressive patients was observed, as well as small amplitude in the pre-frontal cortex and reduced P3a response. This can be evidence of impaired information processing, cognitive flexibility, working memory, executive functions and ability to shift the attention and processing to the target and away from distracting stimuli in BD. Such neuropsychological impairments are related to different BD symptoms, which should be known and considered, in order to develop effective clinical treatment strategies.

Eye Movement in Unipolar and Bipolar Depression: A Systematic Review of the Literature

BACKGROUND

The analysis of eye movements (EM) by eye-tracking has been carried out for several decades to investigate mood regulation, emotional information processing, and psychomotor disturbances in depressive disorders.

METHOD

A systematic review of all English language PubMed articles using the terms "saccadic eye movements" OR "eye-tracking" AND "depression" OR "bipolar disorders" was conducted using PRISMA guidelines. The aim of this review was to characterize the specific alterations of EM in unipolar and bipolar depression.

RESULTS

Findings regarding psychomotor disturbance showed an increase in reaction time in prosaccade and antisaccade tasks in both unipolar and bipolar disorders. In both disorders, patients have been reported to have an attraction for negative emotions, especially for negative pictures in unipolar and threatening images in bipolar disorder. However, the pattern could change with aging, elderly unipolar patients disengaging key features of sad and neutral stimuli. METHODological limitations generally include small sample sizes with mixed unipolar and bipolar depressed patients.

CONCLUSION

Eye movement analysis can be used to discriminate patients with depressive disorders from controls, as well as patients with bipolar disorder from patients with unipolar depression. General knowledge concerning psychomotor alterations and affective regulation strategies associated with each disorder can also be gained thanks to the analysis. Future directions for research on eye movement and depression are proposed in this review.

Cognitive and emotional biomarkers of melancholic depression: An iSPOT-D report

BACKGROUND

Depressed patients with melancholic features have distinct impairments in cognition and anhedonia, but it remains unknown whether these impairments can be quantified on neurocognitive biomarker tests of behavioral performance. We compared melancholic major depressive disorder (MDD) patients to non-melancholic MDD patients and controls on a neurocognitive test battery that assesses eight general and emotional cognitive domains including the hypothesized decision-making and reward-threat perception.

METHODS

MDD outpatients (n=1008) were assessed using a computerized battery of tests. MDD participants met DSM-IV criteria for MDD and had a score ≥16 on the 17-item Hamilton Rating Scale for Depression. Melancholic MDD was defined using the Mini-International Neuropsychiatric Interview and a psychomotor disturbance observer-rated CORE measure score >7. Controls were age- and gender-matched with no previous DSM-IV or significant medical history.

RESULTS

Melancholic participants (33.7% of the MDD sample) exhibited significantly poorer performance than controls across each domain of cognitive function and for speed of emotion identification and implicit emotion priming. Compared to the non-melancholic group, specific disturbances were seen on tests of information speed, decision speed, and reward-relevant emotional processing of happy expressions, even after co-varying for symptom severity.

LIMITATIONS

Assessments were taken at only one medication-free time point. Reward was investigated using an emotional faces task.

CONCLUSIONS

Melancholic MDD is distinguished by a specific neurocognitive marker profile consistent with reduced decision-making capacity under time demands and loss of reward sensitivity. This profile suggests an underlying deficit in mesolimbic-cortical circuitry for motivationally-directed behavior.

Adaptive learning can result in a failure to profit from good conditions: implications for understanding depression

BACKGROUND AND OBJECTIVES

Depression is a major medical problem diagnosed in an increasing proportion of people and for which commonly prescribed psychoactive drugs are frequently ineffective. Development of treatment options may be facilitated by an evolutionary perspective; several adaptive reasons for proneness to depression have been proposed. A common feature of many explanations is that depressive behaviour is a way to avoid costly effort where benefits are small and/or unlikely. However, this viewpoint fails to explain why low mood persists when the situation improves. We investigate whether a behavioural rule that is adapted to a stochastically changing world can cause inactivity which appears similar to the effect of depression, in that it persists after the situation has improved.

METHODOLOGY

We develop an adaptive learning model in which an individual has repeated choices of whether to invest costly effort that may result in a net benefit. Investing effort also provides information about the current conditions and rates of change of the conditions.

RESULTS

An individual following the optimal behavioural strategy may sometimes remain inactive when conditions are favourable (i.e. when it would be better to invest effort) when it is poorly informed about the current environmental state. Initially benign conditions can predispose an individual to inactivity after a relatively brief period of negative experiences.

CONCLUSIONS AND IMPLICATIONS

Our approach suggests that the antecedent factors causing depressed behaviour could go much further back in an individual s history than is currently appreciated. The insights from our approach have implications for the ongoing debate about best treatment options for patients with depressive symptoms.

Impairment and distress patterns distinguishing the melancholic depression subtype: an iSPOT-D report

BACKGROUND

This study seeks to provide a comprehensive and systematic evaluation of baseline clinical and psychological features and treatment response characteristics that differentiate Major Depressive Disorder (MDD) outpatients with and without melancholic features. Reflecting the emphasis in DSM-5, we also include impairment and distress.

METHODS

Participants were assessed pre-treatment on clinical features (severity, risk factors, comorbid conditions, illness course), psychological profile (personality, emotion regulation), functional capacity (social and occupational function, quality of life) and distress/coping (negativity bias, emotional resilience, social skills, satisfaction with life). Participants were randomized to sertraline, escitalopram or venlafaxine extended-release and re-assessed post-treatment at 8 weeks regarding remission, response, and change in impairment and distress.

RESULTS

Patients with melancholic features (n=339; 33.7%) were distinguished clinically from non-melancholics by more severe depressive symptoms and greater exposure to abuse in childhood. Psychologically, melancholic patients were defined by introversion, and a greater use of suppression to regulate negative emotion. Melancholics also had poorer capacity for social and occupational function, and physical and psychological quality of life, along with poorer coping, reflected in less emotional resilience and capacity for social skills. Post-treatment, melancholic patients had lower remission and response, but some of this effect was due to the more severe symptoms pre-treatment. The distress/coping outcome measure of capacity for social skills remained significantly lower for melancholic participants.

LIMITATIONS

Due to the cross-sectional nature of this study, causal pathways cannot be concluded.

CONCLUSIONS

Findings provide new insights into a melancholic profile of reduced ability to function interpersonally or effectively deal with one׳s emotions. This distinctly poorer capacity for social skills remained post-treatment. The pre-treatment profile may account for some of the difficulty in achieving remission or response with treatment.

Melancholic-Like behaviors and circadian neurobiological abnormalities in melatonin MT1 receptor knockout mice

BACKGROUND

Melancholic depression, described also as endogenous depression, is a mood disorder with distinctive specific psychopathological features and biological homogeneity, including anhedonia, circadian variation of mood, psychomotor activation, weight loss, diurnal cortisol changes, and sleep disturbances. Although several hypotheses have been proposed, the etiology of this disorder is still unknown.

METHODS

Behavioral, electrophysiological and biochemical approaches were used to characterize the emotional phenotype, serotonergic and noradrenergic electrical activity, and corticosterone in melatonin MT1 receptor knockout mice and their wild type counterparts, during both light and dark phases.

RESULTS

Melatonin MT1 receptor knockout mice have decreased mobility in the forced swim and tail suspension tests as well as decreased sucrose consumption, mostly during the dark/inactive phase. These mood variations are reversed by chronic treatment with the tricyclic antidepressant desipramine. In addition, MT1 receptor knockout mice exhibit psychomotor disturbances, higher serum levels of corticosterone the dark phase, and a blunted circadian variation of corticosterone levels. In vivo electrophysiological recordings show a decreased burst-firing activity of locus coeruleus norepinephrine neurons during the dark phase. The circadian physiological variation in the spontaneous firing activity of high-firing neuronal subpopulations of both norepinephrine neurons and dorsal raphe serotonin neurons are abolished in MT1 knockout mice.

CONCLUSIONS

These data demonstrate that melatonin MT1 receptor knockout mice recapitulate several behavioral and neurobiological circadian changes of human melancholic depression and, for the first time, suggest that the MT1 receptor may be implicated in the pathogenesis of melancholic depression and is a potential pharmacological target for this mental condition.

Digital Clock Drawing: differentiating "thinking" versus "doing" in younger and older adults with depression

Psychomotor slowing has been documented in depression. The digital Clock Drawing Test (dCDT) provides: (i) a novel technique to assess both cognitive and motor aspects of psychomotor speed within the same task and (ii) the potential to uncover subtleties of behavior not previously detected with non-digitized modes of data collection. Using digitized pen technology in 106 participants grouped by Age (younger/older) and Affect (euthymic/unmedicated depressed), we recorded cognitive and motor output by capturing how the clock is drawn rather than focusing on the final product. We divided time to completion (TTC) for Command and Copy conditions of the dCDT into metrics of percent of drawing (%Ink) versus non-drawing (%Think) time. We also obtained composite Z-scores of cognition, including attention/information processing (AIP), to explore associations of %Ink and %Think times to cognitive and motor performance. Despite equivalent TTC, %Ink and %Think Command times (Copy n.s.) were significant (AgeXAffect interaction: p=.03)-younger depressed spent a smaller proportion of time drawing relative to thinking compared to the older depressed group. Command %Think time negatively correlated with AIP in the older depressed group (r=-.46; p=.02). Copy %Think time negatively correlated with AIP in the younger depressed (r=-.47; p=.03) and older euthymic groups (r=-.51; p=.01). The dCDT differentiated aspects of psychomotor slowing in depression regardless of age, while dCDT/cognitive associates for younger adults with depression mimicked patterns of older euthymics.

Psychomotor retardation in elderly untreated depressed patients

BACKGROUND

Psychomotor retardation (PR) is one of the core features in depression according to DSM V (1), but also aging in itself causes cognitive and psychomotor slowing. This is the first study investigating PR in relation to cognitive functioning and to the concomitant effect of depression and aging in a geriatric population ruling out contending effects of psychotropic medication.

METHODS

A group of 28 non-demented depressed elderly is compared to a matched control group of 20 healthy elderly. All participants underwent a test battery containing clinical depression measures, cognitive measures of processing speed, executive function and memory, clinical ratings of PR, and objective computerized fine motor skill-tests. Statistical analysis consisted of a General Linear Method multivariate analysis of variance to compare the clinical, cognitive, and psychomotor outcomes of the two groups.

RESULTS

Patients performed worse on all clinical, cognitive, and PR measures. Both groups showed an effect of cognitive load on fine motor function but the influence was significantly larger for patients than for healthy elderly except for the initiation time.

LIMITATIONS

Due to the restrictive inclusion criteria, only a relatively limited sample size could be obtained.

CONCLUSION

With a medication free sample, an additive effect of depression and aging on cognition and PR in geriatric patients was found. As this effect was independent of demand of effort (by varying the cognitive load), it was apparently not a motivational slowing effect of depression.

Psychomotor retardation in depression: a systematic review of diagnostic, pathophysiologic, and therapeutic implications

Psychomotor retardation is a central feature of depression which includes motor and cognitive impairments. Effective management may be useful to improve the classification of depressive subtypes and treatment selection, as well as prediction of outcome in patients with depression. The aim of this paper was to review the current status of knowledge regarding psychomotor retardation in depression, in order to clarify its role in the diagnostic management of mood disorders. Retardation modifies all the actions of the individual, including motility, mental activity, and speech. Objective assessments can highlight the diagnostic importance of psychomotor retardation, especially in melancholic and bipolar depression. Psychomotor retardation is also related to depression severity and therapeutic change and could be considered a good criterion for the prediction of therapeutic effect. The neurobiological process underlying the inhibition of activity includes functional deficits in the prefrontal cortex and abnormalities in dopamine neurotransmission. Future investigations of psychomotor retardation should help improve the understanding of the pathophysiological mechanisms underlying mood disorders and contribute to improving their therapeutic management.

Psychomotor retardation in depression: a systematic review of diagnostic, pathophysiologic, and therapeutic implications

Psychomotor retardation is a central feature of depression which includes motor and cognitive impairments. Effective management may be useful to improve the classification of depressive subtypes and treatment selection, as well as prediction of outcome in patients with depression. The aim of this paper was to review the current status of knowledge regarding psychomotor retardation in depression, in order to clarify its role in the diagnostic management of mood disorders. Retardation modifies all the actions of the individual, including motility, mental activity, and speech. Objective assessments can highlight the diagnostic importance of psychomotor retardation, especially in melancholic and bipolar depression. Psychomotor retardation is also related to depression severity and therapeutic change and could be considered a good criterion for the prediction of therapeutic effect. The neurobiological process underlying the inhibition of activity includes functional deficits in the prefrontal cortex and abnormalities in dopamine neurotransmission. Future investigations of psychomotor retardation should help improve the understanding of the pathophysiological mechanisms underlying mood disorders and contribute to improving their therapeutic management.

The impact of high-frequency repetitive transcranial magnetic stimulation on fine motor functions in medication-resistant major depression

OBJECTIVES

Although high-frequency repetitive transcranial magnetic stimulation (HF-rTMS) over the left dorsolateral prefrontal cortex (DLPFC) has been reported to improve mood symptoms in major depressive disorder (MDD), research on its impact on psychomotor symptoms is scarce. This study assessed the psychomotor effects of 1 and 10 sessions, respectively, of HF-rTMS over the left DLPFC.

METHODS

Ten HF-rTMS sessions were applied in 21 medication-free MDD patients over a 2-week period. At the beginning, one placebo (sham)-controlled rTMS session was also applied in a cross-over, single-blind design. Psychomotor variables were digitally recorded during completion of a Fitts' task, at baseline, after the first and second real/sham session and at the end point.

RESULTS

The total 10-session treatment period resulted in a decrease of depression severity. One HF-rTMS session resulted in improvements on the Fitts' task, without a difference between active and sham stimulation, however. No further improvements occurred from session 2 to session 10.

CONCLUSIONS

No evidence was provided to link the observed psychomotor improvements to HF-rTMS stimulation, as a practice effect could have impacted the significant psychomotor outcomes.

Gender differences in symptomatic profiles of depression: results from the São Paulo Megacity Mental Health Survey

BACKGROUND

Few studies have investigated symptomatic subtypes of depression and their correlates by gender.

METHODS

Data are from the São Paulo Megacity Mental Health Survey. Symptom profiles of 1207 subjects (864 women; 343 men) based upon symptoms of the worst depressive episode in lifetime were examined through latent class analysis. Correlates of gender-specific latent classes were analyzed by logistic regression.

RESULTS

For both men and women, a 3-class model was the best solution. A mild class was found in both genders (41.1% in women; 40.1% in men). Gender differences appeared in the most symptomatic classes. In women, they were labeled melancholic (39.3%) and atypical (19.5%), differing among each other in somatic/vegetative symptoms. The melancholic class presented inhibition and eating/sleeping symptoms in the direction of decreasing, whereas the atypical class had increased appetite/weight, and hypersomnia. For men, symptoms that differentiate the two most symptomatic classes were related to psychomotor activity: a melancholic/psychomotor retarded (40.4%) and agitated depression (19.6%). The highest between-class proportion of agitation and racing thoughts was found among men in the agitated class, with similarity to bipolar mixed state.

LIMITATIONS

Analyses were restricted to those who endorsed questions about their worst lifetime depressive episode; the standardized assessment by lay interviewers; the small male sample size.

CONCLUSIONS

The construct of depression of current classifications is heterogeneous at the symptom level, where gender different subtypes can be identified. These symptom profiles have potential implications for the nosology and the therapeutics of depression.

Major depressive disorder is associated with broad impairments on neuropsychological measures of executive function: a meta-analysis and review

Cognitive impairments are now widely acknowledged as an important aspect of major depressive disorder (MDD), and it has been proposed that executive function (EF) may be particularly impaired in patients with MDD. However, the existence and nature of EF impairments associated with depression remain strongly debated. Although many studies have found significant deficits associated with MDD on neuropsychological measures of EF, others have not, potentially due to low statistical power, task impurity, and diverse patient samples, and there have been no recent, comprehensive, meta-analyses investigating EF in patients with MDD. The current meta-analysis uses random-effects models to synthesize 113 previous research studies that compared participants with MDD to healthy control participants on at least one neuropsychological measure of EF. Results of the meta-analysis demonstrate that MDD is reliably associated with impaired performance on neuropsychological measures of EF, with effect sizes ranging from 0.32 to 0.97. Although patients with MDD also have slower processing speed, motor slowing alone cannot account for these results. In addition, some evidence suggests that deficits on neuropsychological measures of EF are greater in patients with more severe current depression symptoms, and those taking psychotropic medications, whereas evidence for effects of age was weaker. The results are consistent with the theory that MDD is associated with broad impairment in multiple aspects of EF. Implications for treatment of MDD and theories of EF are discussed. Future research is needed to establish the specificity and causal link between MDD and EF impairments.

Impact of one HF-rTMS session on fine motor function in right-handed healthy female subjects: a comparison of stimulation over the left versus the right dorsolateral prefrontal cortex

BACKGROUND

Repetitive transcranial magnetic stimulation (rTMS) is a non-invasive tool to investigate neural conduction in motor processes. Most rTMS research has been conducted by targeting the primary motor cortex. Several studies have also found increased psychomotor speed after rTMS of the dorsolateral prefrontal cortex (DLPFC). However, these studies were mainly performed in psychiatric patients, only targeting the left DLPFC, and often without sham control. Moreover, psychomotor speed is mostly measured based on tasks that also require higher executive functions.

METHODS

Here, we examined the lateralized effect of one sham-controlled high-frequency rTMS session applied to the left or right DLPFC on fine motor function in 36 healthy right-handed females, using the Fitts' paradigm.

RESULTS

We found a significant improvement in psychomotor speed only after actively stimulating the right DLPFC.

CONCLUSION

Our results support the assumption of a right prefrontal neural network implicated in visuomotor behavior and performance processes, and that the improvement in psychomotor speed is not a secondary effect of decreased mood.

Neural correlates of disbalanced motor control in major depression

BACKGROUND

Motor retardation is a common symptom of major depressive disorder (MDD). Despite the existence of various assessment methods, little is known on the pathobiology of motor retardation. We aimed to elucidate aspects of motor control investigating the association of objective motor activity and resting state cerebral blood flow (CBF).

METHODS

Nineteen control subjects and 20 MDD patients were investigated using arterial spin labeling (ASL) at 3T in the morning to quantify resting state CBF. Afterwards wrist actigraphy was recorded for 24h. CBF, group and activity level (AL) were entered into a whole brain general linear model.

RESULTS

MDD patients had reduced AL. Both groups had linear associations of AL and CBF in bilateral rostral prefrontal cortex. Groups differed in four clusters associated with motor control. In controls a positive association was found in the left caudal cingulate zone (CCZ) and an inverse association in the right external globus pallidus (GPe). MDD patients had positive associations in the right orbitofrontal cortex and inverse associations in the left supplemental motor area.

LIMITATIONS

Patients were on antidepressant medication.

CONCLUSIONS

The pattern of associations between CBF and AL suggest disbalanced motor control in MDD. Findings are in line with the hypothesis of dopamine deficits contributing to motor retardation in MDD.

Frontostriatal functional connectivity in major depressive disorder

BACKGROUND

Abnormalities of the striatum and frontal cortex have been reported consistently in studies of neural structure and function in major depressive disorder (MDD). Despite speculation that compromised connectivity between these regions may underlie symptoms of MDD, little work has investigated the integrity of frontostriatal circuits in this disorder.

METHODS

Functional magnetic resonance images were acquired from 21 currently depressed and 19 never-disordered women during wakeful rest. Using four predefined striatal regions-of-interest, seed-to-whole brain correlations were computed and compared between groups.

RESULTS

Compared to controls, depressed participants exhibited attenuated functional connectivity between the ventral striatum and both ventromedial prefrontal cortex and subgenual anterior cingulate cortex. Depressed participants also exhibited stronger connectivity between the dorsal caudate and dorsal prefrontal cortex, which was positively correlated with severity of the disorder.

CONCLUSIONS

Depressed individuals are characterized by aberrant connectivity in frontostriatal circuits that are posited to support affective and cognitive processing. Further research is required to examine more explicitly the link between patterns of disrupted connectivity and specific symptoms of depression, and the extent to which these patterns precede the onset of depression and normalize with recovery from depressive illness.

Internally vs. externally triggered movements in patients with major depression

BACKGROUND

Psychomotor retardation is a prominent clinical feature of major depression. While several studies investigated these deficits, differences between internally and externally triggered response selection and initiation are less well understood. In the current study, we delineate internally vs. externally driven response selection and initiation in depression and their relation to basic psychomotor functioning.

METHODS

20 inpatients diagnosed with a (unipolar) major depression and 20 closely matched healthy controls performed a computerized motor paradigm assessing differences between internally and externally cued movements. Psychomotor performance and basic memory functions were assessed using a neuropsychological test-battery. To examine within group homogeneity a multivariate clustering approach was applied.

RESULTS

Patients featured a global slowing of internally and externally cued response selection compared to controls, as well as impairments in basic psychomotor functioning. Yet, basic motor speed was preserved. Furthermore, patients were more severely impaired when movements involved internal response selection. The data-driven clustering revealed two patient subgroups, which both showed psychomotor disturbances, while only one featured slowing of response selection.

INTERPRETATION

The results suggest a differential rather than a global psychomotor slowing in major depression with specific impairments of visuospatial and attentional processing as cognitive aspects of psychomotor functioning. As found for depression, in Parkinson's disease internally cued movements are more severely affected than externally cued reactions. Both may therefore be caused by dopaminergic deregulation due to frontostriatal deficits. Finally, multivariate clustering of behavioral data may be a promising future approach to identify subtypes of psychomotor or cognitive disturbances in different patient populations.

Psychomotor function and response inhibition in chronic fatigue syndrome

Most research points to cognitive slowing in chronic fatigue syndrome (CFS), although there have been negative reports. The present study is one of few that examines fine motor processing and the inhibition of automatic responses in a well-characterised CFS population. A total of 35 female CFS patients without current major depression and 25 female controls performed two computerised figure-copying tasks. The cognitive and fine motor processing of visual-spatial information was measured by recording reaction time (RT) and movement time (MT), respectively. The inhibition of automatic responses was assessed by introducing 'conflicting patterns' (i.e., patterns that were difficult to draw from the preferred left to right). A multivariate general linear model was adopted for the statistical analysis of the movement recordings. As a result, CFS was significantly associated with longer RT and MT in the pooled and in the task-specific analyses. However, there was no interaction between disease status and conflicting character of the patterns. In conclusion, these performance data on the figure-copying tasks provide confirmatory evidence for psychomotor slowing in CFS, but not for a disturbed inhibition of automatic responses. Computerised figure-copying tasks may be promising tools for use in neurobiological research and clinical trials in CFS.

Melancholic versus non-melancholic depression: differences on cognitive function. A longitudinal study protocol

BACKGROUND

Cognitive dysfunction is common among depressed patients. However, the pattern and magnitude of impairment during episodes of major depressive disorder (MDD) through to clinical remission remains unclear. Heterogeneity of depressive patients and the lack of longitudinal studies may account for contradictory results in previous research.

METHODS/DESIGN

This longitudinal study will analyze cognitive differences between CORE-defined melancholic depressed patients (n = 60) and non-melancholic depressed patients (n = 60). A comprehensive clinical and cognitive assessment will be performed at admission and after 6 months. Cognitive dysfunction in both groups will be longitudinally compared, and the persistence of cognitive impairment after clinical remission will be determined.

DISCUSSION

The study of neuropsychological dysfunction and the cognitive changes through the different phases of depression arise a wide variety of difficulties. Several confounding variables must be controlled to determine if the presence of depression could be considered the only factor accounting for group differences.

A longitudinal study of cognitive function in melancholic and non-melancholic subtypes of major depressive disorder

BACKGROUND

Research concerning cognition in depression has often yielded inconsistent findings. The presence of mixed melancholic and non-melancholic subtypes of major depressive disorder (MDD) in most previous research may explain some of the contradictory results (Hickie, 1996).

METHODS

This longitudinal study compared the cognitive performance of people with melancholic (n=17) and non-melancholic (n=17) MDD admitted to one of two university hospitals. Participants received an extensive clinical and cognitive assessment at admission and again 3 months after recovery and discharge.

RESULTS

Overall, participants with melancholia had selective memory deficits with broader impairment of executive control skills. Specifically, after correcting for depression severity, they performed more poorly on tests requiring memory acquisition, mental flexibility, set-shifting, selective attention, concept-formation and multi-tasking compared to those with non-melancholic depression. These deficits were present at both assessments suggesting that the increased initial severity of cognitive deficits for those with melancholia mean that they require a longer time to recovery.

LIMITATIONS

The clinical homogeneity of the study sample may underestimate the extent of cognitive impairment for those presenting with comorbid illness and/or significant drug/alcohol histories.

CONCLUSIONS

These findings indicate that the depressed group with melancholia have a distinctly different and more impaired cognitive profile to those without melancholic features and suggest that these clinical subtypes should be considered separately in future research concerning MDD. Furthermore, the melancholic group appears to require longer periods for cognitive recovery and this has implications for return to work and daily functioning following clinical discharge.

HF-rTMS treatment decreases psychomotor retardation in medication-resistant melancholic depression

Repetitive Transcranial Magnetic Stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) might be a promising treatment strategy for depression. As one of the key features of melancholic depression is disturbances in psychomotor activity, we wanted to evaluate whether HF-rTMS treatment could influence psychomotor symptoms. Twenty antidepressant-free unipolar melancholic depressed patients, all at least stage III medication-resistant, were studied. All were treated with 10 sessions of High-Frequency (HF)-rTMS applied to the left dorsolateral prefrontal cortex (DLPFC) under MRI guidance. Forty percent of the patients showed a reduction of at least 50% on their initial 17-item Hamilton Depression Rating Score (HDRS) scale and were defined as clinical responders. Regardless of clinical outcome HF-rTMS treatment resulted in significant decreases on the Depressive Retardation Rating Scale (DRRS) scores. Although this was an open study in a relatively small sample, our results suggest that HF-rTMS might act on the 'psychomotor' level and these findings could add some further information as to why this kind of treatment can be beneficial for severely depressed patients of the melancholic subtype.

Computerized kinematic analysis of the clock drawing task in elderly people with mild major depressive disorder: an exploratory study

BACKGROUND

Developments in data collection technology enable evaluation of kinematic characteristics of the drawing process. We examined the clock drawing task in elderly patients with mild Major Depressive Disorder (MDD), assessed the relative importance of kinematic measures that differentiate the groups and analyzed associations between computerized measures, and the cognitive and depression status of the study groups.

METHODS

The participants comprised 20 elderly people with mild MDD and 20 matched controls. Both groups performed a clock drawing task using a computerized system. Kinematic measures included: number of segments drawn, performance time, pressure implemented towards the drawing surface, and pen azimuth. Three representative spatial characteristics were analyzed per segments drawn on the paper: height, width and length. The clock drawing tasks were blindly scored with Freedman's method. Cognitive state was quantified using the Mini-mental State Examination (MMSE) and depression with the Geriatric Depression Scale (GDS).

RESULTS

Freedman's method found no between-group differences. Pressure and azimuth measures and spatial measures of segments height, width and length were significantly lower in the mild MDD group, while the number of paper segments and performance time did not differ. The azimuth measure correlated with the GDS score, and pressure with the MMSE and the GDS scores. Spatial measures did not correlate with either the MMSE or GDS. Pressure, segment width and length, azimuth and segment height allowed correct classification of 81.1% of the participants.

CONCLUSIONS

A computerized system focusing on the clock drawing task might be sensitive to altered performance among elderly people with mild MDD.

Stroop performance in major depression: selective attention impairment or psychomotor slowness?

BACKGROUND

Numerous neuropsychological studies reported impaired Stroop performance in major depressive disorder (MDD) patients.

METHODS

The present study attempted to identify possible neuropsychological mechanisms involved in this impairment in untreated MDD outpatients (n=75) as compared to healthy subjects (n=83). Inspection Time, Finger Tapping, Simple and Choice Reaction Time were considered as measures of perceptual, motor, psychomotor speed, and response selection, respectively.

RESULTS

MDD patients performed significantly slower than healthy controls in the neutral and the congruent conditions, but not in the incongruent ones. In order to identify predictors of Stroop performance, linear hierarchical regressions analyses were performed. Age, motor and psychomotor speed were predictors of response time and accuracy on Stroop performance. Significant correlations between response time and the number of errors in all three Stroop conditions were found in MDD patients, while such a correlation was obtained in the healthy controls only in the incongruent condition.

LIMITATIONS

Although education was included as a covariate in our analyses, suggesting that the observed effects could not be ascribed to education differences, further testing with education-matched samples is warranted.

CONCLUSIONS

Our study shows that the Stroop task performance is affected by both aging and MDD. Impairment in the Stroop performance can be predicted by psychomotor slowness and by vigilance level in MDD outpatients, but not by impairment of selective attention per se.

Longitudinal changes of day-time and night-time gross motor activity in clinical responders and non-responders of major depression

Psychomotor retardation (PR) is among the most important features of depression. This study investigates the development of day- and night-time as well as intensity and quantity of circadian motor activity during a 4-week course of treatment among 27 patients with depression compared to 27 healthy controls. A diagnosis of major depression was made using SCID. Motor activity was continuously measured with an actigraph during the study and clinical course of depression with HAM-D-21. Motor activity was described as the quantity and intensity of movements during day- and night- time. Clinically improved patients had significantly intensified movements after 4 weeks, compared to subjects with <50% improvement on HAM-D. While the measures of day-time level of movements captured the clinical improvement of depression, clinical improvement was not reflected by the night-time measurements. This study demonstrates that the separated analysis of level and quantity of movements supports a better understanding of the nature of psychomotor retardation during depression. The subdivision in day- and night-time activity objectively measured with actigraphy captures distinct patterns of motor activity and represents prognostic factors in the treatment outcome of depression. The study also highlights the importance of studying the intensity of movements separately from the quantity of movements in relation to treatment outcome.

Impaired implicit learning and reduced pre-supplementary motor cortex size in early-onset major depression with melancholic features

BACKGROUND

Major depression is a heterogeneous disorder. Biological markers and cognitive tasks have been employed to distinguish clinical subtypes but results have been inconclusive.

METHODS

The current study assessed implicit learning with the Serial Reaction Time Task (SRTT) known to be sensitive to frontostriatal dysfunctions and regional brain volumes of the anterior supplementary motor area (pre-SMA) in participants with early-onset major depression (MD) of either melancholic (n=26) or non-melancholic (n=9) subtype, and 26 matched controls.

RESULTS

Depressive subjects with melancholic features but not those with non-melancholic depression showed implicit learning deficits. This deficit could not be explained in terms of more severe depression or psychomotor retardation. Regional volumes of the right pre-SMA were reduced in depressive subjects with melancholic features.

LIMITATIONS

Medication effects in depressive subjects and the small size of the non-melancholic sample should be taken into consideration when reviewing the implications of these results.

CONCLUSIONS

Deficits in implicit motor sequence learning seem to be an additional characteristic of the melancholic subtype of depression. It might be linked to dysfunction within structural or functionally altered frontostriatal circuits. Use of implicit sequence learning tasks could offer useful diagnostic and aetiological cues for future research.

A study of intensity dependence of the auditory evoked potential (IDAEP) in medicated melancholic and non-melancholic depression

BACKGROUND

Major Depressive Disorder is widely recognised to be a heterogeneous syndrome with numerous depressive phenotypes, one of which is melancholic depression. Patients with melancholic depression exhibit treatment responses and outcomes that differ from patients with non-melancholic depression. The current study aimed to assess whether differences existed between melancholic and non-melancholic subtypes of depression, as measured by the event related potential, intensity dependence of the auditory evoked potential (IDAEP).

METHODS

IDAEP was assessed in 14 melancholic and 13 non-melancholic depressed subjects and 14 controls.

RESULTS

The melancholic patients had a significantly shallower IDAEP slope than the non-melancholic patients not explained by depression severity or age.

LIMITATIONS

Antidepressants were taken by all patients in this study and the effect of continual use of these drugs on the IDAEP slopes has yet to be confirmed.

CONCLUSIONS

These results provide support for neurobiological differences between melancholic and non-melancholic depressive subtypes. Melancholic depression may be characterized by ongoing over function of the serotonin system in spite of medication treatment.

Working memory span and motor and cognitive speed in schizophrenia

OBJECTIVE

The aim of this study was to investigate the verbal working memory deficit and decrease of motor and cognitive speed in patients with schizophrenia, and to clarify their associations with negative and depressive symptomatology.

METHODS

Forty patients with schizophrenia and 41 healthy control individuals were administered the backward digit span to assess the working memory capacity, along with 3 tests of processing speed.

RESULTS

Patients demonstrated reduced backward digit span, as well as decreased motor and cognitive speed. Regression analyses indicated that the backward digit span was associated with cognitive speed. It was not associated with either negative or depressive symptoms. Decreased processing speed was unrelated to negative symptoms, but the depression score was significantly associated with the cognitive speed measure.

CONCLUSIONS

Working memory and processing speed seem to share a cognitive component. Depression, but not negative symptoms, affects processing speed, especially by decreasing cognitive speed.

Psychomotor functioning in chronic fatigue syndrome and major depressive disorder: a comparative study

BACKGROUND

Studies comparing chronic fatigue syndrome (CFS) and major depressive disorder (MDD) reported similarities as well as differences between the two disorders. However, whereas psychomotor symptoms have been studied extensively in MDD, such research in CFS is more limited. Moreover, the few studies that compared cognitive and motor performance in MDD and CFS yielded inconsistent results. This study hence directly compares fine psychomotor functioning in both syndromes.

METHODS

Thirty-eight patients diagnosed with CFS without a current major depressive episode (MDE), 32 MDD patients with a current MDE and 38 healthy controls performed two computerized copying tasks differing in complexity: a line-copying task that mainly requires motor effort and a figure-copying task requiring additional cognitive efforts. All participants were female. A multivariate general linear model was used to compute group differences.

RESULT

Overall, both patient groups performed more slowly than the controls. Compared to CFS patients, patients with MDD needed significantly more time to copy the single lines but no such between-group performance difference was observed for the figure reproductions. In this latter copying task, the increasing complexity of the figures resulted in prolonged reaction times for all three participant groups with the effect being larger and the magnitude similar for the two patient groups.

LIMITATIONS

All patients were female and most were on psychotropic medication.

CONCLUSIONS

Both the MDD and CFS patients tested demonstrated an overall fine motor slowing, with the motor component being more affected in the MDD patients than in the CFS patients while both patient groups showed similar cognitive impairments.