Differential effects of reboxetine and citalopram on hand-motor function in patients suffering from major depression

Psychomotor retardation is linked to frontal alpha asymmetry in major depression

BACKGROUND

Psychomotor disturbances are a main clinical feature of major depressive disorder (MDD) but little is known about their EEG signature. One of the most replicated EEG findings in MDD is resting frontal asymmetry in the alpha band (FAA), which is thought to be a correlate of withdrawal behavior and reduced approach motivation. The purpose of this study was to assess psychomotor alterations, alpha band power, FAA and investigate the association between them.

METHODS

20 MDD patients and 19 healthy subjects were enrolled. Alpha power and FAA scores were calculated from a resting state EEG. Wrist actigraphy was recorded from the non-dominant arm for 24 h and activity level scores (AL) were extrapolated from the wakeful periods.

RESULTS

MDD patients had a left-lateralized frontal alpha activity and lower AL scores when compared to healthy subjects. A significant correlation was found between mean FAA and AL scores. A negative covariance between power in the lower alpha range and AL scores over the motor cortex bilaterally was detected.

LIMITATIONS

Relatively small sample size. Patients were pharmacologically treated with antidepressants.

CONCLUSIONS

This study replicates the finding of left-lateralized FAA and lower AL scores in MDD patients, and establishes the first evidence of significant correlations between alpha power, FAA scores and measures of motor activity, which may be interpreted as an expression of impaired motivational drive in MDD.

Cognitive and psychomotor effects of three months of escitalopram treatment in elderly patients with major depressive disorder

BACKGROUND

Although psychomotor retardation (PR) and cognitive disfunctioning are essential symptoms of elderly depressed patients, the differential effect of treatment with an SSRI in the elderly on these symptoms has hardly got any attention in studies with objective experimental measures. Since effects appear relatively slower in elderly, this study evaluates the effect on cognitive and psychomotor functioning as compared to mood, on four points during a twelve week follow up of monotreatment with escitalopram.

METHOD

28 non-demented elderly unipolar depressive patients on 5-20mg escitalopram were compared to 20 matched 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 at the start and after 2, 6 and 12 weeks. Statistical analysis consisted of a General Linear Model (GLM) repeated measures multivariate analysis of variance of completers to compare the psychomotor and cognitive outcomes of the two groups.

RESULTS

Although, apart from the significant mood effect, no interaction effects were found for the psychomotor and cognitive tasks, the means in general show a trend of differential effects in cognitive and psychomotor functions, with smaller effects and delayed timeframes and with presence of subgroups compared to mood effects.

LIMITATION

Longer follow up studies are necessary to evaluate differential long term effects.

CONCLUSION

In elderly, moderate effects of SSRI treatment on mood precede slow or limited effects on cognition and psychomotor retardation.

Citalopram versus other anti-depressive agents for depression

BACKGROUND

Recent US and UK clinical practice guidelines recommend that second-generation antidepressants should be considered amongst the best first-line options when drug therapy is indicated for a depressive episode. Systematic reviews have already highlighted some differences in efficacy between second-generation antidepressants. Citalopram, one of the first selective serotonin reuptake inhibitors (SSRI) introduced in the market, is one of these antidepressant drugs that clinicians use for routine depression care.

OBJECTIVES

To assess the evidence for the efficacy, acceptability and tolerability of citalopram in comparison with tricyclics, heterocyclics, other SSRIs and other conventional and non-conventional antidepressants in the acute-phase treatment of major depression.

SEARCH METHODS

We searched The Cochrane Collaboration Depression, Anxiety and Neurosis Controlled Trials Register and the Cochrane Central Register of Controlled Trials up to February 2012. No language restriction was applied. We contacted pharmaceutical companies and experts in this field for supplemental data.

SELECTION CRITERIA

Randomised controlled trials allocating patients with major depression to citalopram versus any other antidepressants.

DATA COLLECTION AND ANALYSIS

Two reviewers independently extracted data. Information extracted included study characteristics, participant characteristics, intervention details and outcome measures in terms of efficacy (the number of patients who responded or remitted), patient acceptability (the number of patients who failed to complete the study) and tolerability (side-effects).

MAIN RESULTS

Thirty-seven trials compared citalopram with other antidepressants (such as tricyclics, heterocyclics, SSRIs and other antidepressants, either conventional ones, such as mirtazapine, venlafaxine and reboxetine, or non-conventional, like hypericum). Citalopram was shown to be significantly less effective than escitalopram in achieving acute response (odds ratio (OR) 1.47, 95% confidence interval (CI) 1.08 to 2.02), but more effective than paroxetine (OR 0.65, 95% CI 0.44 to 0.96) and reboxetine (OR 0.63, 95% CI 0.43 to 0.91). Significantly fewer patients allocated to citalopram withdrew from trials due to adverse events compared with patients allocated to tricyclics (OR 0.54, 95% CI 0.38 to 0.78) and fewer patients allocated to citalopram reported at least one side effect than reboxetine or venlafaxine (OR 0.64, 95% CI 0.42 to 0.97 and OR 0.46, 95% CI 0.24 to 0.88, respectively).

AUTHORS' CONCLUSIONS

Some statistically significant differences between citalopram and other antidepressants for the acute phase treatment of major depression were found in terms of efficacy, tolerability and acceptability. Citalopram was more efficacious than paroxetine and reboxetine and more acceptable than tricyclics, reboxetine and venlafaxine, however, it seemed to be less efficacious than escitalopram. As with most systematic reviews in psychopharmacology, the potential for overestimation of treatment effect due to sponsorship bias and publication bias should be borne in mind when interpreting review findings. Economic analyses were not reported in the included studies, however, cost effectiveness information is needed in the field of antidepressant trials.

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.

Measuring motor activity in major depression: the association between the Hamilton Depression Rating Scale and actigraphy

Despite the use of actigraphy in depression research, the association of depression ratings and quantitative motor activity remains controversial. In addition, the impact of recurring episodes on motor activity is uncertain. In 76 medicated inpatients with major depression (27 with a first episode, 49 with recurrent episodes), continuous wrist actigraphy for 24h and scores on the Hamilton Depression Rating Scale (HAMD) were obtained. In addition, 10 subjects of the sample wore the actigraph over a period of 5 days, in order to assess the reliability of a 1-day measurement. Activity levels were stable over 5 consecutive days. Actigraphic parameters did not differ between patients with a first or a recurrent episode, and quantitative motor activity failed to correlate with the HAMD total score. However, of the motor-related single items of the HAMD, the item activities was associated with motor activity parameters, while the items agitation and retardation were not. Actigraphy is consistent with clinical observation for the item activities. Expert raters may not correctly rate the motor aspects of retardation and agitation in major depression.

Psychomotor symptoms in depression: a diagnostic, pathophysiological and therapeutic tool

BACKGROUND

Psychomotor disturbances have been described repeatedly over many centuries. More recently, Sobin and Sackeim [Sobin, C., Sackeim, H.A., 1997. Psychomotor symptoms of depression. Am. J. Psychiatry. 154, 4-17.] discussed the relevance of psychomotor symptoms in depression in an extensive review. Since their report, new pathophysiological, diagnostic and therapeutic findings have been published. In the current review of the recent literature, we aim to argue the importance of psychomotor symptoms in depression and propose directions for future research.

METHOD

A review of all the relevant reports on this topic, published between 1996 and 2006, was conducted.

RESULTS

Several assessment methods demonstrate the diagnostic and pathophysiological significance of psychomotor symptoms. Antidepressants show differential effects on psychomotor performance and findings concerning the symptoms' predictive capacity for clinical response are contradictory. Numerous imaging studies as well as studies on the neurotransmitter systems and the HPA-axis contribute to the elucidation of the neurobiological processes underlying impaired psychomotor functioning in depression.

CONCLUSIONS

Psychomotor disturbances are of great diagnostic significance for the depressive subtype of melancholia. To enhance the conceptualisation of the construct 'psychomotor' a standardised battery for their assessment is recommended. As to the symptoms' predictive therapeutic power, to date research into functional outcome and studies applying objective experimental assessment methods are lacking. Moreover, the reported pathophysiological importance of dopamine for 'retarded depression' still warrants translation to the daily practice.

Hand-motor dysfunction in depression: characteristics and pharmacological effects

Motor retardation is a relevant aspect of depression. Kinematic analysis of movements can be applied to explore which type of motor dysfunction is associated with depression and to examine motor side effects of antidepressants. Using this tool, we aimed to investigate fine motor performance in patients suffering from depression and to compare a selective noradrenaline re-uptake inhibitor (NARI) (reboxetine) and a selective serotonin reuptake inhibitor (SSRI) (citalopram) regarding motor side effects after 4 weeks of treatment. In the first study (I), we examined 37 depressed patients and 37 healthy subjects using a digitizing graphic tablet and kinematic analysis of handwriting and rapid drawing movements. Both groups were comparable regarding age, gender distribution, handedness (preponderance of right-handers) and educational level. In the second study (ll), we examined different types of hand movements in 16 depressed patients receiving citalopram (flexible dosage) and 12 depressed patients treated with reboxetine (varying dosage) using the afore-mentioned methods. Both groups were comparable regarding age, gender, handedness and the baseline Hamilton Depression Rating Scale total score. I: Depressed patients performed drawing with significantly less regular velocity than controls (p < 0.001), but normal velocity. Handwriting of depressed patients was abnormally slow (p = 0.04). II: Reboxetine led to a significant improvement of repetitive drawing movements in depression. In contrast, citalopram had no pronounced effects on hand movements in depressed patients. I: Irregular patterns of velocity peaks in depressed patients point to basal ganglia dysfunction and/or deficient activity of the sensorimotor cortex and the supplementary motor area as possible substrates of hand-motor disturbances in depression. II: Computer-aided analysis of hand movements is a sensitive tool for the registration of differential pharmaceutical effects on hand-motor function in depression.

Influence of initial use of serotonergic antidepressants on antiparkinsonian drug use in levodopa-using patients

OBJECTIVE

To assess whether there is an association between initial use of serotonergic antidepressants and changes in antiparkinsonian drug treatment.

METHODS

A retrospective cohort study was performed with the PHARMO record linkage system. All patients from 1994 until 2004 of 40 years or older who were first time users of an antidepressant and who had used a levodopa-containing drug at least 180 days before initiation of the antidepressant were included. The maximum follow-up time was 180 days. The first change in antiparkinsonian drug treatment, defined as an increase in the daily dosage of any antiparkinsonian drug, the start of a new antiparkinsonian drug or a change in the dosage form during the follow-up period, was taken as an endpoint. Antidepressants were classified in two ways: according to their class [selective serotonin reuptake inhibitors (SSRI), tricyclic antidepressants (TCA) or other antidepressants] or by the extent of their inhibition of serotonin reuptake (high, intermediate or low).

RESULTS

A total of 221 patients was included in our study. The adjusted hazard ratio for a change in antiparkinsonian drug treatment was 0.7 (95% CI 0.3-1.5) comparing SSRI with TCA users, and it was 0.9 (95% CI 0.4-2.1) comparing users of other antidepressants with TCA users. The adjusted hazard ratio for a change in antiparkinsonian drug treatment was 0.6 (95% CI 0.3-1.4) comparing users of antidepressants with high versus low extent of inhibition of serotonin reuptake, and it was 0.7 (95% CI 0.3-1.4) comparing users of antidepressants with intermediate versus low extent of inhibition of serotonin reuptake.

CONCLUSION

Based on these observations, we found no evidence to be more cautious using SSRIs or serotonergic antidepressants compared to other antidepressants in patients with Parkinson's disease.

No effects of enhanced central norepinephrine on finger-sequence learning and attention

RATIONALE

When paired with training, substances that increase monoaminergic transmission in the brain support motor and language learning in healthy subjects and in rehabilitation after brain lesions.

OBJECTIVES

To test the hypotheses that enhancement of central norepinephrine by the selective norepinephrine reuptake inhibitor reboxetine (1) improves skilled motor performance, (2) promotes skilled motor learning, and (3) does not exert these effects by modulation of attention.

METHODS

In a double blind, placebo-controlled, crossover study in healthy, adult subjects (n=16), finger-sequence performance and learning was measured after the stimulation of the central noradrenergic system with a single dose (8 mg) of reboxetine and placebo. Effects on attention were assessed by the standardized continuous performance test "CPT-M".

RESULTS

No differential effects of reboxetine or placebo on finger-sequence performance, learning and parameters of attention were found.

CONCLUSION

Selective stimulation of the central noradrenergic system did not promote skilled motor learning or performance as assessed by finger-sequences. The plasticity-enhancing effect of reboxetine, documented in other studies, appears to be dependent on specific neurophysiological and neuropsychological characteristics of the task, and cannot be generalized to other behavioral paradigms.

Multi-target strategies for the improved treatment of depressive states: Conceptual foundations and neuronal substrates, drug discovery and therapeutic application

Major depression is a debilitating and recurrent disorder with a substantial lifetime risk and a high social cost. Depressed patients generally display co-morbid symptoms, and depression frequently accompanies other serious disorders. Currently available drugs display limited efficacy and a pronounced delay to onset of action, and all provoke distressing side effects. Cloning of the human genome has fuelled expectations that symptomatic treatment may soon become more rapid and effective, and that depressive states may ultimately be "prevented" or "cured". In pursuing these objectives, in particular for genome-derived, non-monoaminergic targets, "specificity" of drug actions is often emphasized. That is, priority is afforded to agents that interact exclusively with a single site hypothesized as critically involved in the pathogenesis and/or control of depression. Certain highly selective drugs may prove effective, and they remain indispensable in the experimental (and clinical) evaluation of the significance of novel mechanisms. However, by analogy to other multifactorial disorders, "multi-target" agents may be better adapted to the improved treatment of depressive states. Support for this contention is garnered from a broad palette of observations, ranging from mechanisms of action of adjunctive drug combinations and electroconvulsive therapy to "network theory" analysis of the etiology and management of depressive states. The review also outlines opportunities to be exploited, and challenges to be addressed, in the discovery and characterization of drugs recognizing multiple targets. Finally, a diversity of multi-target strategies is proposed for the more efficacious and rapid control of core and co-morbid symptoms of depression, together with improved tolerance relative to currently available agents.