Effects of fluoxetine on psychomotor performance, cognitive function and sleep in depressed patients

Prescription of antidepressants and the risk of road traffic crash in the elderly: a case-crossover study

AIM

To investigate the impact of antidepressants on the risk of road traffic crash in the elderly.

METHODS

Reports from the Universal Quebec Automobile Insurance Agency database were matched with data on antidepressant prescription from the Quebec Health Insurance Agency. The case-crossover analysis consisted in comparing exposure during a period immediately before the crash with exposure during earlier periods, for the same subject.

RESULTS

One hundred and nine thousand four hundred and six drivers between 66 and 84 years of age involved in a traffic crash between 1988 and 2000 were included. Two thousand nine hundred and nineteen (2.7%) were exposed to an antidepressant on the day of the crash. Case-crossover analysis found an increased risk of crash in drivers with a prescription of antidepressants before their crash when compared with a prescription of antidepressants 4 to 8 months before the crash (OR = 1.19, 95% CI 1.08, 1.30 to 1.42. 95% CI 1.30, 1.55). With the most recent control periods, results were not significant.

CONCLUSION

A patient's mental state is probably more similar between two periods that are close to each other than up to 8 months before. Consequently, the risk of crash is likely to be linked to symptoms of depression.

Little evidence for the graphical markers of depression

The purpose was to test whether specific characteristics of handwriting can distinguish patients diagnosed with major depression from healthy controls and patients with bipolar disorder. Handwriting samples from 30 patients with major depressive disorder and 30 patients in the bipolar depressive phase were compared to samples from 30 patients in the bipolar manic phase and 60 healthy controls. Forensic document experts examined all 150 written samples of the same text and empirically measured graphical aspects potentially related to depression, such as direction of the baseline, pen pressure, tremor, forms of the letters 'm', 'n', 'a', and 'o', sizes of the letters and writing zones, the initial and final shapes of letters, slant, and impulse. Three handwriting parameters of 32 examined differed significantly between controls and patients with depression (major depression or depressed bipolar patients). However, there were no statistically significant differences in these parameters between depressed patients and bipolar patients in the manic phase, indicating that these handwriting characteristics cannot distinguish depressed patients from manic patients. The main hypothesis, that psychomotor slowing is visible in handwriting, was not confirmed.

Fluoxetine versus other types of pharmacotherapy for depression

BACKGROUND

Depression is common in primary care and is associated with marked personal, social and economic morbidity, thus creating significant demands on service providers. The antidepressant fluoxetine has been studied in many randomised controlled trials (RCTs) in comparison with other conventional and unconventional antidepressants. However, these studies have produced conflicting findings.Other systematic reviews have considered selective serotonin reuptake inhibitor (SSRIs) as a group which limits the applicability of the indings for fluoxetine alone. Therefore, this review intends to provide specific and clinically useful information regarding the effects of fluoxetine for depression compared with tricyclics (TCAs), SSRIs, serotonin-noradrenaline reuptake inhibitors (SNRIs), monoamineoxidase inhibitors (MAOIs) and newer agents, and other conventional and unconventional agents.

OBJECTIVES

To assess the effects of fluoxetine in comparison with all other antidepressive agents for depression in adult individuals with unipolar major depressive disorder.

SEARCH METHODS

We searched the Cochrane Collaboration Depression, Anxiety and Neurosis Review Group Controlled Trials Register (CCDANCTR)to 11May 2012. This register includes relevant RCTs from the Cochrane Central Register of Controlled Trials (CENTRAL) (all years),MEDLINE (1950 to date), EMBASE (1974 to date) and PsycINFO (1967 to date). No language restriction was applied. Reference lists of relevant papers and previous systematic reviews were handsearched. The pharmaceutical company marketing fluoxetine and experts in this field were contacted for supplemental data.

SELECTION CRITERIA

All RCTs comparing fluoxetine with any other AD (including non-conventional agents such as hypericum) for patients with unipolar major depressive disorder (regardless of the diagnostic criteria used) were included. For trials that had a cross-over design only results from the first randomisation period were considered.

DATA COLLECTION AND ANALYSIS

Data were independently extracted by two review authors using a standard form. Responders to treatment were calculated on an intention-to-treat basis: dropouts were always included in this analysis. When data on dropouts were carried forward and included in the efficacy evaluation, they were analysed according to the primary studies; when dropouts were excluded from any assessment in the primary studies, they were considered as treatment failures. Scores from continuous outcomes were analysed by including patients with a final assessment or with the last observation carried forward. Tolerability data were analysed by calculating the proportion of patients who failed to complete the study due to any causes and due to side effects or inefficacy. For dichotomous data, odds ratios (ORs) were calculated with 95% confidence intervals (CI) using the random-effects model. Continuous data were analysed using standardised mean differences (SMD) with 95% CI.

MAIN RESULTS

A total of 171 studies were included in the analysis (24,868 participants). The included studies were undertaken between 1984 and 2012. Studies had homogenous characteristics in terms of design, intervention and outcome measures. The assessment of quality with the risk of bias tool revealed that the great majority of them failed to report methodological details, like the method of random sequence generation, the allocation concealment and blinding. Moreover, most of the included studies were sponsored by drug companies, so the potential for overestimation of treatment effect due to sponsorship bias should be considered in interpreting the results. Fluoxetine was as effective as the TCAs when considered as a group both on a dichotomous outcome (reduction of at least 50% on the Hamilton Depression Scale) (OR 0.97, 95% CI 0.77 to 1.22, 24 RCTs, 2124 participants) and a continuous outcome (mean scores at the end of the trial or change score on depression measures) (SMD 0.03, 95% CI -0.07 to 0.14, 50 RCTs, 3393 participants). On a dichotomousoutcome, fluoxetine was less effective than dothiepin or dosulepin (OR 2.13, 95% CI 1.08 to 4.20; number needed to treat (NNT) =6, 95% CI 3 to 50, 2 RCTs, 144 participants), sertraline (OR 1.37, 95% CI 1.08 to 1.74; NNT = 13, 95% CI 7 to 58, 6 RCTs, 1188 participants), mirtazapine (OR 1.46, 95% CI 1.04 to 2.04; NNT = 12, 95% CI 6 to 134, 4 RCTs, 600 participants) and venlafaxine(OR 1.29, 95% CI 1.10 to 1.51; NNT = 11, 95% CI 8 to 16, 12 RCTs, 3387 participants). On a continuous outcome, fluoxetine was more effective than ABT-200 (SMD -1.85, 95% CI -2.25 to -1.45, 1 RCT, 141 participants) and milnacipran (SMD -0.36, 95% CI-0.63 to -0.08, 2 RCTs, 213 participants); conversely, it was less effective than venlafaxine (SMD 0.10, 95% CI 0 to 0.19, 13 RCTs,3097 participants). Fluoxetine was better tolerated than TCAs considered as a group (total dropout OR 0.79, 95% CI 0.65 to 0.96;NNT = 20, 95% CI 13 to 48, 49 RCTs, 4194 participants) and was better tolerated in comparison with individual ADs, in particular amitriptyline (total dropout OR 0.62, 95% CI 0.46 to 0.85; NNT = 13, 95% CI 8 to 39, 18 RCTs, 1089 participants), and among the newer ADs ABT-200 (total dropout OR 0.18, 95% CI 0.08 to 0.39; NNT = 3, 95% CI 2 to 5, 1 RCT, 144 participants), pramipexole(total dropout OR 0.12, 95% CI 0.03 to 0.42, NNT = 3, 95% CI 2 to 5, 1 RCT, 105 participants), and reboxetine (total dropout OR0.60, 95% CI 0.44 to 0.82, NNT = 9, 95% CI 6 to 24, 4 RCTs, 764 participants).

AUTHORS' CONCLUSIONS

The present study detected differences in terms of efficacy and tolerability between fluoxetine and certain ADs, but the clinical meaning of these differences is uncertain.Moreover, the assessment of quality with the risk of bias tool showed that the great majority of included studies failed to report details on methodological procedures. Of consequence, no definitive implications can be drawn from the studies' results. The better efficacy profile of sertraline and venlafaxine (and possibly other ADs) over fluoxetine may be clinically meaningful,as already suggested by other systematic reviews. In addition to efficacy data, treatment decisions should also be based on considerations of drug toxicity, patient acceptability and cost.

Cognitive performance in depressed patients after chronic use of antidepressants

RATIONALE

Depressive disorders are conditions that often require continuous treatment, and it is therefore important to evaluate the consequences of prolonged administration. There are few studies assessing cognitive functions of depressed patients after long-term use of antidepressants.

OBJECTIVES

This study evaluated the cognitive performance of depressed patients treated with antidepressants for at least 6 months.

METHODS

Patients with major depression (DSM-IV) using imipramine for 2.4+/-0.6 years (mean+/-SE), clomipramine for 2.8+/-1.2 years, fluoxetine for 1.8+/-0.3 years and sertraline for 1.5+/-0.3 years were compared to matched controls (sex, age and educational level) without any psychiatric diagnosis. Memory evaluation consisted of episodic, implicit and working memory tests as well as metamemory assessment.

RESULTS

(a) Psychomotor performance of patients taking imipramine was worse than that of controls in inserting pins and a visual reaction time task; on the performance of tapping the difference from controls varied according to dose/weight for patients taking clomipramine and fluoxetine. (b) For memory tests, differences between patients taking sertraline and controls were observed in the number of digits and words recalled; the difference between patients and controls varied according to dose/weight on the number of familiar words correctly completed for patients taking clomipramine and on digit span backward for those taking sertraline. (c) Metamemory was worse in all patient groups irrespective of patients' clinical state.

CONCLUSIONS

The impairment in psychomotor and memory performances associated with these antidepressants seems to be of low intensity and of questionable clinical relevance.

Antidepressants and their effect on sleep

Given the relationship between sleep and depression, there is inevitably going to be an effect of antidepressants on sleep. Current evidence suggests that this effect depends on the class of antidepressant used and the dosage. The extent of variation between the effects of antidepressants and sleep may relate to their mechanism of action. This systematic review examines randomised-controlled trials (RCTs) that have reported the effect that antidepressants appear to have on sleep. RCTs are not restricted to depressed populations, since several studies provide useful information about the effects on sleep in other groups. Nevertheless, the distinction is made between those studies because the participant's health may influence the baseline sleep profiles and the effect of the antidepressant. Insomnia is often seen with monoamine oxidase inhibitors (MAOIs), with all tricyclic antidepressants (TCAs) except amitriptyline, and all selective serotonin reuptake inhibitors (SSRIs) with venlafaxine and moclobemide as well. Sedation has been reported with all TCAs except desipramine, with mirtazapine and nefazodone, the TCA-related maprotiline, trazodone and mianserin, and with all MAOIs. REM sleep suppression has been observed with all TCAs except trimipramine, but especially clomipramine, with all MAOIs and SSRIs and with venlafaxine, trazodone and bupropion. However, the effect on sleep varies between compounds within antidepressant classes, differences relating to the amount of sedative or alerting (insomnia) effects, changes to baseline sleep parameters, differences relating to REM sleep, and the degree of sleep-related side effects.

Memory consolidation in sleep; dream or reality

We discuss several lines of evidence refuting the hypothesis that procedural or declarative memories are processed/consolidated in sleep. One of the strongest arguments against a role for sleep in declarative memory involves the demonstration that the marked suppression or elimination of REM sleep in subjects on antidepressant drugs or with brainstem lesions produces no detrimental effects on cognition. Procedural memory, like declarative memory, undergoes a slow, time-dependent period of consolidation. A process has recently been described wherein performance on some procedural tasks improves with the mere passage of time and has been termed "enhancement." Some studies, but not others, have reported that the consolidation/enhancement of perceptual and motor skills is dependent on sleep. We suggest that consolidation or enhancement, initiated in waking with task acquisition, could in some instances extend to sleep, but sleep would serve no unique role in these processes. In sum, there is no compelling evidence to support a relationship between sleep and memory consolidation.

Subjective assessment of the effects of CNS-active drugs on sleep by the Leeds sleep evaluation questionnaire: a review

The Leeds sleep evaluation questionnaire (LSEQ) comprises ten self-rating 100 mm line analogue questions concerned with sleep and early morning behaviour. A literature search identified 83 studies in peer-reviewed journals that reported the use of the LSEQ for psychopharmacological investigations of drug effects on self-reported aspects of sleep. High internal consistency and reliability of the questionnaire have been demonstrated. Findings from studies involving a variety of psychoactive agents indicated that the LSEQ was able to quantify subjective impressions of sleep and waking and the effects of drugs in healthy volunteers, depressed and insomnia patients. In accordance with their known activity profile nocturnal administration of sedative hypnotic agents and antihistamines induced dose-related improvements in self-reported ease of getting to sleep, and quality of sleep but a decrease in alertness and behavioural integrity the following morning. Psychostimulants, on the other hand, impaired subjective ratings of sleep and increased early morning alertness. Antidepressants and certain anxiolytic agents improved both self-reported sleep aspects and early morning alertness. Treatment effects measured by the LSEQ corresponded to those measured for the same drugs by other assessment methods. These data indicate that the LSEQ is a robust and reliable instrument for psychopharmacological evaluations. Self-evaluations of sleep, as obtained by the LSEQ, can therefore provide consistent and meaningful measures for estimating the effectiveness of sleep modulators and sedative-hypnotic drugs.

The impact of antidepressants on sleep and anxiety: a comparative study of fluoxetine and dothiepin using the Leeds Sleep Evaluation Questionnaire

Fluoxetine (20 mg) was compared to dothiepin (150 mg) in a multicentre, prospective, double blind, randomised clinical trial involving 125 patients with major depression treated for an initial phase of 6 weeks and then followed up for a further 6 months. There was no difference in the efficacy of the two drugs based on the results of established rating scales (MADRS, HAM-D, BPRS). The impact of both drugs on sleep measured using the Leeds Sleep Evaluation Questionnaire showed no significant differences between treatments, however drowsiness and disturbed sleep were reported more frequently as side effects with dothiepin. Symptoms of anxiety responded equally well to both treatments. The short term and long term tolerability of dothiepin was inferior to that of fluoxetine. The place of dothiepin in treatment should be reassessed in the light of its anticholinergic adverse event profile, particularly in the elderly. Copyright 2000 John Wiley & Sons, Ltd.

Serotonin and human information processing: fluvoxamine can improve reaction time performance

Fluvoxamine is a specific serotonin reuptake inhibitor. Recent evidence suggests that this antidepressive drug shortens the reaction time (RT) of healthy volunteers. The first objective of the present study was to decipher whether this effect is due to an improvement in information processing per se or to the adoption of an error-prone strategy. The second objective was to locate the effect of fluvoxamine within the series of information processing stages by means of Sternberg's additive factor method. After administration of a single oral dose of fluvoxamine (100 mg) or a placebo (randomized double-blind, cross-over design), eight healthy volunteers performed a choice RT task in which stimulus intensity, stimulus-response compatibility and response repertoire were manipulated. Fluvoxamine shortened RT without decreasing the accuracy of the responses. This demonstrates that fluvoxamine improves information processing per se. The effect of fluvoxamine was additive on RT with the respective effects of stimulus intensity and stimulus-response compatibility. This result suggests that fluvoxamine spares the processing stages of stimulus preprocessing and response selection.

Long-term effects of antidepressants on balance, equilibrium, and postural reflexes

To assess the long-term effects of antidepressant medication on balance, equilibrium, and postural reflexes, we studied 30 patients, ages 20-76 years, who had a diagnosis of depressive disorder (as defined by DSM-III-R criteria) and had been treated with tricyclic antidepressants (TCAs) or selective serotonin reuptake inhibitors (SSRIs) for > or = 1 year. They were assessed by a Balance Master System. The assessment included three tasks: static balance, rhythmic weight shift, and limits of stability. When compared with 30 nonhospitalized healthy controls (of comparable age and the same sex), patients who took TCAs showed impaired balance function in all main indices. The results suggest that the impairment of balance function includes motor coordination, fine-motor control, postural reflexes, maintaining equilibrium, and reaction time. No obvious impairment of balance function was observed in patients who took SSRIs.

Fine motor retardation and depression

New computerized techniques allow the precise measurement of psychomotor retardation in patients with a major depressive episode (MDE). One such technique is the analysis of writing and drawing behaviour during figure copying tasks. In the present study, 22 inpatients with an MDE were compared to 22 normal controls. Three tasks were used: the drawing of lines and simple figures, the copying of complex figures and a task in which figures had to be rotated. Objectives were to provide support for earlier findings that the patients were slower than the controls and to explore the cognitive and motor processes involved. Two strategies were applied: analysis of the reaction time and movement time and their different components, and manipulation of the cognitive and motor demands. Patients showed considerable retardation with most of the kinematic variables. Motor deficits and cognitive slowing down contributed to this retardation. Cognitive difficulties increased with increasing complexity of the task.