Studies on the modulation of the sleep-wakefulness continuum in man by fluoxetine, a 5-HT uptake inhibitor

Comparison of Effect of Antidepressants on Psychomotor Functions

OBJECTIVE

The comparison of the effect of antidepressants on psychomotor functions in patients with endogenous depression.

MATERIALS AND METHODS

This prospective interventional study was carried out at a tertiary care teaching hospital on 95 literate patients with newly diagnosed endogenous depression matching inclusion and exclusion criteria. Patients were prescribed either desvenlafaxine (50 mg) or fluoxetine (40 mg) or sertraline (50 mg). Psychomotor functions were assessed by digit letter substitution, six letter cancellation, choice reaction time, hand steadiness and flicker fusion test at the baseline 1^st month and 3^rd month. Efficacy of drugs was also measured by Hamilton rating scale for depression. Data were analyzed by using ANOVA and P < 0.05 was considered as statistically significant.

RESULTS

A total of 95 patients were enrolled. Fluoxetine, desvenlafaxine, and sertraline were prescribed in 32, 32, and 31 patients, respectively. At the end of 3 months, a significant improvement in psychomotor functions was observed in patients treated with sertraline (P < 0.05), while desvenlafaxine-treated patients did not show any significant change in any of the tests. Surprisingly, fluoxetine-treated patients showed deterioration in all psychomotor tests (P < 0.05). Hamilton rating score improved at the end of 3 months treatment as compared to baseline. Most commonly observed adverse reactions in all three drug groups were nausea (n = 20), dizziness (n = 3), headache (n = 20), and diarrhea (n = 3).

CONCLUSION

Sertraline significantly improves psychomotor function as compared to desvenlafaxine while fluoxetine impairs.

Increased frontal sleep slow wave activity in adolescents with major depression

Sleep slow wave activity (SWA), the major electrophysiological characteristic of deep sleep, mirrors both cortical restructuring and functioning. The incidence of Major Depressive Disorder (MDD) substantially rises during the vulnerable developmental phase of adolescence, where essential cortical restructuring is taking place. The goal of this study was to assess characteristics of SWA topography in adolescents with MDD, in order to assess abnormalities in both cortical restructuring and functioning on a local level. All night high-density EEG was recorded in 15 patients meeting DSM-5 criteria for MDD and 15 sex- and age-matched healthy controls. The actual symptom severity was assessed using the Children's Depression Rating Scale-Revised (CDRS-R). Topographical power maps were calculated based on the average SWA of the first non-rapid eye movement (NREM) sleep episode. Depressed adolescents exhibited significantly more SWA in a cluster of frontal electrodes compared to controls. SWA over frontal brain regions correlated positively with the CDRS-R subscore "morbid thoughts". Self-reported sleep latency was significantly higher in depressed adolescents compared to controls whereas sleep architecture did not differ between the groups. Higher frontal SWA in depressed adolescents may represent a promising biomarker tracing cortical regions of intense use and/or restructuring.

Pharmacology I: effects on sleep of commonly used ICU medications

Critically ill patients are almost universally administered medications to treat their acute illnesses and to maximize their comfort. The effects of many of these medications on their sleep, however, may be important. It is known that critically ill patients have severely disrupted sleep and that this disrupted sleep has a negative impact on ICU outcomes. This article reviews how some commonly used ICU medications may affect patients' sleep.

Use of selective serotonin reuptake inhibitors and sleep disturbances in community-dwelling older women

OBJECTIVES

To determine the association between use of selective serotonin reuptake inhibitors (SSRIs) and objective measures of sleep disturbances in older community-dwelling women, including women without evidence of depression.

DESIGN

Cross-sectional study.

SETTING

Four U.S. clinical centers.

PARTICIPANTS

Two thousand eight hundred fifty-three women aged 71 and older (2,630 nonusers of antidepressants and 223 taking SSRIs alone, not in combination with other antidepressants).

MEASUREMENTS

Medication use, assessed using an interviewer-administered questionnaire with verification of use from medication containers and computerized dictionary used to categorize type of medication; evidence of depression assessed using self-report or a score of 6 or higher on the Geriatric Depression Scale; and sleep parameters measured using a wrist actigraph, with data collected for an average of four consecutive 24-hour periods.

RESULTS

Of the overall cohort of 2,853 women and of 2,337 women without evidence of depression, sleep disturbances were more common in women taking SSRIs than in those not taking antidepressants. After excluding women with evidence of depression and adjusting for multiple potential confounders, women taking SSRIs were more likely to have a sleep duration of 5 hours or less (multivariate odds ratio (MOR)=2.15, 95% confidence interval (CI)=1.04-4.47), sleep efficiency less than 70% (MOR=2.37, 95% CI=1.32-4.25), sleep latency of 1 hour or more (MOR=3.99, 95% CI=2.29-6.96) and eight or more long wake episodes (MOR=1.75, 95% CI=0.99-3.10).

CONCLUSION

SSRI use by older women, including those without evidence of depression, is associated with a greater likelihood of sleep disturbances, including poorer sleep efficiency, longer sleep latency, and sleep fragmentation, manifested by multiple long wake episodes. These results add to the uncertainty regarding risks and benefits of SSRI use in aged populations.

Maternal fluoxetine infusion does not alter fetal endocrine and biophysical circadian rhythms in pregnant sheep

OBJECTIVE

Depression during pregnancy is frequently treated with the selective serotonin reuptake inhibitor (SSRI), fluoxetine (FX), commonly known as Prozac (Eli Lilly & Co, Indianapolis, IN). FX potentiates serotoninergic neurotransmission and serotonin has been implicated in the regulation of circadian rhythms. We have therefore investigated the effect of chronic administration of FX on maternal and fetal circadian rhythms in sheep.

METHODS

Following an initial bolus dose of 70 mg FX, an 8-day continuous infusion of FX (n = 11, 98.5 microg/kg x d) was performed. Controls (n = 13) were treated with sterile water vehicle only. Maternal and fetal plasma melatonin and prolactin concentrations were determined every 3 hours for 24 hours and then every 6 hours for 24 hours beginning on the fourth day of infusion.

RESULTS

FX treatment did not alter either the basal or circadian rhythms of either maternal or fetal plasma melatonin and prolactin concentrations. Fetal cardiovascular and behavioral state parameters were measured continuously. While the incidence of low-voltage (LV) electrocortical (ECOG) activity was significantly reduced in fetuses in the FX group, there was no effect of FX on the diurnal rhythms in fetal arterial pressure, heart rate, breathing movements, or behavioral state.

CONCLUSION

These results show that maternal FX treatment does not result in significant alterations in maternal and fetal hormonal and behavioral circadian rhythms.

Antidepressants and sleep: a qualitative review of the literature

Most antidepressants change sleep; in particular, they alter the physiological patterns of sleep stages recorded overnight with EEG and other physiological measures. These effects are greatest and most consistent on rapid eye movement (REM) sleep, and tend to be in the opposite direction to the sleep abnormalities found in major depression, but are usually of greater degree. Reductions in the amount of REM sleep and increases in REM sleep onset latency are seen after taking antidepressants, both in healthy volunteers and in depressed patients. Antidepressants that increase serotonin function by blocking reuptake or by inhibiting metabolism have the greatest effect on REM sleep. The decrease in amount of REM sleep appears to be greatest early in treatment, and gradually diminishes during long-term treatment, except after monoamine oxidase inhibitors when REM sleep is often absent for many months. Sleep initiation and maintenance are also affected by antidepressants, but the effects are much less consistent between drugs. Some antidepressants such as clomipramine and the selective serotonin receptor inhibitors (SSRIs), particularly fluoxetine, are sleep-disturbing early in treatment and some others such as amitriptyline and the newer serotonin 5-HT2-receptor antagonists are sleep promoting. However, these effects are fairly short-lived and there are very few significant differences between drugs after a few weeks of treatment. In general, the objectively measured sleep of depressed patients improves during 3-4 weeks of effective antidepressant treatment with most agents, as does their subjective impression of their sleep. Sleep improvement earlier in treatment may be an important clinical goal in some patients, perhaps when insomnia is particularly distressing, or to ensure compliance. In these patients, the choice of a safely used and effective antidepressant which improves sleep in short term is indicated. Patients with other sleep disorders such as restless legs syndrome and REM sleep behaviour disorder should be identified before choosing a treatment, as some antidepressants worsen these conditions. Conversely, there is evidence that some antidepressants may be useful in the treatment of sleep disorders such as night terrors.

Pain reactivity in 2-month-old infants after prenatal and postnatal serotonin reuptake inhibitor medication exposure

OBJECTIVE

In this prospective study, we examined biobehavioral responses to acute procedural pain at 2 months of age in infants with prenatal and postnatal selective serotonin reuptake inhibitor (SSRI) medication exposure. Based on previous findings showing reduced pain responses in newborns after prenatal exposure, we hypothesized that altered pain reactivity would also be found at 2 months of age.

METHODS

Facial action (Neonatal Facial Coding System) and cardiac autonomic reactivity derived from the respiratory activity and heart rate variability (HRV) responses to a painful event (heel-lance) were compared between 3 groups of infants: (1) infants with prenatal SSRI exposure alone (n = 11; fluoxetine, n = 2; paroxetine, n = 9); (2) infants with prenatal and postnatal SSRI (via breast milk) exposure (total n = 30; fluoxetine, n = 6; paroxetine, n = 20; sertraline, n = 4); and (3) control infants (n = 22; nonexposed) during baseline, lance, and recovery periods. Measures of maternal mood and drug levels were also obtained, and Bayley Scales of Infant Development-II were administered at ages 2 and 8 months.

RESULTS

Facial action increased in all groups immediately after the lance but was significantly lower in the pSE group during the lance period. HR among infants in the pSE and ppSE groups was significantly lower during recovery. Using measures of HRV and the transfer relationship between heart rate and respiration, exposed infants had a greater return of parasympathetic cardiac modulation in the recovery period, whereas a sustained sympathetic response continued in control infants. Although postnatal exposure via breast milk was extremely low when infant drug levels could be detected in ppSE infants, changes in HR and HRV from lance to recovery were greater compared among infants with levels too low to be quantified. Neither maternal mood nor the presence of clonazepam influenced pain responses.

CONCLUSIONS

Blunted facial-action responses were observed among infants with prenatal SSRI exposure alone, whereas both prenatal and postnatal exposure was associated with reduced parasympathetic withdrawal and increased parasympathetic cardiac modulation during recovery after an acute noxious event. These findings are consistent with patterns of pain reactivity observed in the newborn period in the same cohort. Given that postnatal exposure via breast milk was extremely low and altered biobehavioral pain reactivity was not associated with levels of maternal reports of depression, these data suggest possible sustained neurobehavioral outcomes beyond the newborn period. This is the first study of pain reactivity in infants with prenatal and postnatal SSRI exposure, and our findings were limited by the lack of a depressed nonmedicated control group, small sample size, and understanding of infant behaviors associated with pain reactivity that could have also have been influenced by prenatal SSRI exposure. The developmental and clinical implications of our findings remain unclear, and the mechanisms that may have altered 5-hydroxytryptamine-mediated pain modulation in infants after SSRI exposure remain to be studied. Treating maternal depression with antidepressants during and after pregnancy and promoting breastfeeding in this setting should remain a key goal for all clinicians. Additional study is needed to understand the long-term effects of prenatal and early postnatal SSRI exposure.

Effects of long-term administration of nicotine and fluoxetine on sleep in depressed patients

BACKGROUND

The long-term effects of transdermal nicotine and fluoxetine on sleep and major depression were investigated.

METHODS

Two independent groups of 12 nonsmoking patients with major depression (Hamilton Rating >/=18) served as subjects. The first group received transdermal nicotine (17.5 mg) while the second group received an oral dose of 20 mg/day of fluoxetine, 5 days weekly for 6 months, 3 days weekly at month 7 and 1 day/week at month 8. From the 9(th) to the 14(th) month, once a week a patch without nicotine and an oral placebo substituted nicotine and fluoxetine. Polysomnographic recordings were conducted and depressive symptoms evaluated at baseline and on a monthly basis during medication and during withdrawal.

RESULTS

Nicotine diminished wakefulness and stage 1 and increased REM sleep latency and slow wave sleep throughout the study. A small decrease of REM sleep duration was observed upon nicotine withdrawal. Fluoxetine increased wakefulness, stage 1 duration and REM latency and decreased the sleep efficiency index. Both nicotine and fluoxetine improved mood according to HRS-D scores.

CONCLUSIONS

Nicotine and fluoxetine showed equivalent antidepressant efficacy; however, important differences in sleep parameters were observed between nicotine and fluoxetine, both during their administration and following withdrawal.

REM sleep effects as a biomarker for the effects of antidepressants in healthy volunteers

The potential use of rapid eye movement (REM) sleep effects as a biomarker for the therapeutic effects of antidepressants in healthy volunteers is reviewed. A literature search was performed to select studies investigating the effects of antidepressants on REM sleep. To assess the specificity of REM sleep effects as a biomarker, the effects of other central nervous system drugs on REM sleep were also investigated. A significant REM sleep reduction was shown for 16 of 21 investigated antidepressants after single-dose (mean reduction 34.1%) and for 11/13 drugs after multiple-dose administration (mean reduction 29.2%). The median increase in REM latency was approximatety 60% after single- or multiple-dose administration. REM sleep effects were linearly normalized to therapeutic doses, by dividing the REM sleep effect by the investigated dose and multiplying by the therapeutic dose. Normalized REM sleep effects were highly variable (range -27.0% to 81.8% for REM sleep; range -17.0% to 266.3% for REM latency) and demonstrated no relationship with relevant pharmacological properties of the investigated drugs. No quantifiable dose-response relationship could be constructed after single and multiple dose administration. REM sleep effects were not specific for antidepressants. Benzodiazepines, for example, caused an average dose normalized REM sleep reduction of 8.7% and a median 8.6% increase of REM latency. This review demonstrates that although REM sleep effects occur with most of the antidepressants, it is by itself of limited value as a biomarker for antidepressant action. The specificity for antidepressants is limited, and it does not show a quantitative dose-response relationship to antidepressant agents. This is at least partly due to the complex relationships between drug pharmacokinetics and the variable time course of REM and other sleep stages throughout the night. Models that take these complex relationships into account may provide more comprehensive and quantifiable results.

Effects of 5 weeks of administration of fluoxetine and dothiepin in normal volunteers on sleep, daytime sedation, psychomotor performance and mood

This was a placebo-controlled, double-blind randomized crossover study of long-term (5 weeks) administration of fluoxetine (20 mg/day) and dothiepin (75 mg/day for 1 week followed by 150 mg/day for 4 weeks) in 12 healthy male volunteers. Subjects were studied on day 10 and day 36 of treatment, with tests of nocturnal sleep, driving performance, continuous electroencephalogram (EEG), sleep during scheduled naps, computerized visual attention tasks, saccadic eye movement measurement and visual analogue ratings of mood. Both drugs had a marked suppressive effect on nocturnal rapid eye movement (REM) sleep; these effects were less at 36 days than at 10 days, and fluoxetine decreased and dothiepin increased REM in daytime naps. Sleep fragmentation after fluoxetine is similar to that reported in the literature. We found no sleep-promoting effects of dothiepin, in contrast to our previous single-dose study, and no subjective sleep effects of either drug. Subjects were less sleepy after both antidepressants than placebo at 5 weeks measured by sleep latencies and EEG. Saccadic eye movement measures were significantly faster after 5 weeks of fluoxetine than after 5 weeks of placebo. Reaction times to a peripheral stimulus during computerized tracking task were shorter after 10 days of dothiepin compared with placebo. Driving performance, visual attention and mood ratings showed no treatment effects. Subjective health reports during each 5 weeks of treatment were similar in number for the two drugs but showed a different profile of side-effects.

Fetal behavioural state changes following maternal fluoxetine infusion in sheep

Clinical depression is diagnosed in 5-15% of women during pregnancy, increasing the risk of negative outcomes. Fluoxetine (FX), a selective serotonin reuptake inhibitor, is prescribed during pregnancy. In adults, FX alters sleep patterns with single doses decreasing total sleep time and rapid eye movement sleep. The effects of FX on sleep in the fetus are unknown. However, 5-hydroxytryptophan, the precursor of serotonin, has been reported to prolong high-voltage (HV) electrocortical (ECoG) activity and increase the incidence of fetal breathing movements (FBM) in the sheep fetus. We hypothesize that FX exposure will decrease the incidence of LV ECoG in the fetus. Twenty-one pregnant sheep were surgically prepared for chronic study of blood gases, ECoG activity, eye movements and FBM. After 3 days of recovery, ewes received a 70-mg bolus i.v. infusion of FX or sterile water followed by continuous infusion at a rate of 0.036 mg/min for 8 days. The incidence of low-voltage (LV) ECoG decreased from 54+/-4% on the preinfusion day to 45+/-5% on infusion day 1 in the FX group and remained decreased throughout the infusion period. In addition, the incidence of both eye movements and FBM was decreased on infusion day 1 compared to preinfusion day in the FX group. HV ECoG increased from 39+/-3% on preinfusion day to 68+/-14% on FX infusion day 1 and remained elevated throughout the infusion period. These data show that maternal FX administration alters fetal behavioural state.

Sleep and depression--results from psychobiological studies: an overview

Disturbances of sleep are typical for most depressed patients and belong to the core symptoms of the disorder. Polysomnographic sleep research has demonstrated that besides disturbances of sleep continuity, in depression sleep is characterized by a reduction of slow wave sleep and a disinhibition of REM sleep, with a shortening of REM latency, a prolongation of the first REM period and increased REM density. These findings have stimulated many sleep studies in depressive patients and patients with other psychiatric disorders. In the meantime, several theoretical models, originating from basic research, have been developed to explain sleep abnormalities of depression, like the two-process-model of sleep and sleep regulation, the GRF/CRF imbalance model and the reciprocal interaction model of non-REM and REM sleep regulation. Interestingly, most of the effective antidepressant agents suppress REM sleep. Furthermore, manipulations of the sleep-wake cycle, like sleep deprivation or a phase advance of the sleep period, alleviate depressive symptoms. These data indicate a strong bi-directional relationship between sleep, sleep alterations and depression.

Fluoxetine decreases brain temperature and REM sleep in Syrian hamsters

The antidepressant drug, fluoxetine (FLX), a selective serotonin reuptake inhibitor, was administered to Syrian hamsters, and its acute and chronic effects on EEG sleep and hypothalamic temperature were recorded. Acute fluoxetine treatment at doses of 5, 10, 20 and 40 mg/kg decreased REM sleep and hypothalamic temperature in a dose-dependent manner. It increased NREM sleep, and, at doses of 20 and 40 mg/kg, it increased wakefulness. At 40 mg/kg, it decreased motor activity. During chronic treatment, tolerance developed to FLX's REM sleep-inhibiting effects, but tolerance did not develop to FLX's hypothalamic temperature-decreasing effects. Chronic FLX treatment produced circadian phase-dependent decreases in temperature beyond those that were observed during acute treatment. The apparent dissociation during chronic treatment between FLX's temperature-lowering effects and its REM-decreasing effects might be related to long-term changes in 5HT receptor function or FLX pharmacokinetics.

Serotonergic nuclei of the raphe are not affected in human ageing

Sleep disorders increase with ageing. The serotonergic system has been linked with sleep regulation. In fatal familial insomnia, a prion disease with insomnia as one major clinical feature, we recently observed a disturbance in the serotonergic system as likely substrate of typical symptoms. Using immunohistochemistry for the serotonin synthesizing enzyme, tryptophan hydroxylase, we investigated the serotonergic median raphe nuclei (dorsal raphe nucleus, superior central nucleus, and raphe obscurus nucleus) in brains of an older (n = 12; age range 62-84 years) and a younger group (n = 10; age range 5-29 years). We found no significant difference between age groups in the percentage of neurons able to synthesize serotonin. Other changes might relate to sleep disturbances in the elderly.

REM sleep - by default?

Elements of three old, overlapping theories of REM sleep (REM) function, the Ontogenetic, Homeostatic and Phylogenetic hypotheses, together still provide a plausible framework - that REM (i) is directed towards early cortical development, (ii) "tones up" the sleeping cortex, (iii) can substitute for wakefulness, (iv) has a calming effect. This framework is developed in the light of recent findings. It is argued that the "primitiveness" of REM and its similarity to wakefulness liken it to a default state of "non-wakefulness" or a waking antagonist, anteceding "true" (non-REM) sleep. The "toning up" is reflected by inhibition of motor, sensory and (importantly) emotional systems, together pointing to integrated "flight or fight" activity, that preoccupies/distracts the organism when non-REM is absent and wakefulness unnecessary. Dreaming facilitates this distraction. In rodents, REM can provide stress coping and calming, but REM deprivation procedures incorporating immobility may further enhance stress and confound outcomes. REM "pressure" (e.g. REM rebounds) may be a default from a loss of inhibition of REM by non-REM. REM can be reduced and/or replaced by wakefulness, without adverse effects. REM has little advantage over wakefulness in providing positive cerebral recovery or memory consolidation.

Effects of selective serotonin reuptake inhibitors on objective and subjective sleep quality

The purpose of this paper is to review the effects of selective serotonin (5-HT) reuptake inhibitors on objective and subjective sleep and awakening quality measures. Polysomnography (PSG) demonstrated in both healthy volunteers and depressed patients a decrease in sleep efficiency and total sleep time, a lengthening of sleep latency and a deterioration in sleep continuity, including an increase in the number of awakenings and wake time during the total sleep period. Sleep architecture mostly showed an increase in S1 and S2 and a decrease in S3, S4 and REM sleep as well as a lengthening of REM latency. Objective awakening quality, if measured at all by psychometry, generally showed no decrements. Concerning subjective sleep and awakening quality, normals demonstrated either no changes or a tendency towards a deterioration, while in patients some improvement was observed. Reasons for this discrepancy will be discussed. Novel 5-HT reuptake inhibitors with additional modes of action such as 5-HT2 antagonism (e.g. trazodone, nefazodone) are more likely to improve objective and subjective sleep quality, although some shortcomings may be inherent in regard to comorbidity (e.g. sleep-related breathing disorders). Thus, PSG seems to be a necessity for diagnosis and treatment of complex sleep disorders.

Pharmacology of the selective serotonin reuptake inhibitors in children and adolescents

OBJECTIVE

To review the pharmacology of a new class of medications, the potent selective serotonin reuptake inhibitors (SSRIs), what is known about their metabolism in children and adolescents, and the practical clinical implications of such.

METHOD

Articles were retrieved through index Medicus searches for articles published during the past 10 years on the SSRIs and on pediatric pharmacology.

RESULTS

More than 300 articles were reviewed. Pharmacological data, derived from relevant adult literature, were summarized and extrapolated to children and from the limited pediatric literature. The SSRIs represent a new class of antidepressants with distinct advantages in their side effect profile and their broad therapeutic index over that seen with the tricyclic antidepressants. Their advantage of few anticholinergic side effects and limited cardiovascular toxicities are particularly relevant for the pediatric population. The SSRIs are metabolized via the hepatic cytochrome isoenzyme P450 system, and potential drug-drug interactions are reviewed.

CONCLUSIONS

The SSRIs appear to offer advantages over the tricyclic antidepressants. Unfortunately, pharmacokinetic data are lacking, and systematic studies of safety and efficacy in the pediatric age group are limited. Preliminary reports are encouraging, but further study is required.

Circadian rhythms and the pharmacology of affective illness

The chronic effects of antidepressant drugs (ADs) on circadian rhythms of behavior, physiology and endocrinology are reviewed. The timekeeping properties of several classes of ADs, including tricyclic antidepressants, selective serotonin reuptake inhibitors, monoamine oxidase inhibitors, serotonin agonists and antagonists, benzodiazepines, and melatonin are reviewed. Pharmacological effects on the circadian amplitude and phase, as well as effects on day-night measurements of motor activity, sleep-wake, body temperature (Tb), 3-methoxy-4-hydroxyphenylglycol, cortisol, thyroid hormone, prolactin, growth hormone and melatonin are examined. ADs often lower nocturnal Tb and affect the homeostatic regulation of sleep. ADs often advance the timing and decrease the amount of slow wave sleep, reduce rapid eye movement sleep and increase or decrease arousal. Together, AD effects on nocturnal Tb and sleep may be related to their therapeutic properties. ADs sometimes delay nocturnal cortisol timing and increase nocturnal melatonin, thyroid hormone and prolactin levels; these effects often vary with diagnosis, and clinical state. The effects of ADs on the coupling of the central circadian pacemaker to photic and nonphotic zeitgebers are discussed.

Advances in the management of depression: implications for the obstetrician/gynecologist

The selection of an appropriate medication is important for successfully treating depression in women. Although antidepressants do not differ in their efficacy for the treatment of major depression, they do differ in their side effect profiles, toxicity, and mechanisms of action. Tricyclics, heterocyclics, and newer agents such as bupropion, fluoxetine, paroxetine, sertraline, and venlafaxine are used most commonly to treat depression in women. The dosages, side effects, indications, and precautions for these antidepressants are reviewed. Factors affecting selection of a particular antidepressant, as well as the general management of depression in women, are discussed.

Effect of pharmacologic treatments on the sleep of depressed patients

Antidepressant drugs produce striking effects on sleep architecture that are best understood in terms of their interactions with the monoamine pathways controlling sleep and wakefulness. Many different antidepressant drugs, including tricyclic antidepressants (TCAs), monoamine oxidase inhibitors (MAOIs), and selective 5-hydroxytryptamine (5-HT; serotonin) reuptake inhibitors (SSRIs), decrease rapid eye movement (REM) sleep. The reduction in REM sleep produced by antidepressants may be an important part of their mechanism of action; however, the ability of new antidepressant compounds, such as nefazodone and moclobemide, to increase REM sleep throws doubt on this suggestion. The effects of antidepressants on slow-wave sleep (SWS) are quite diverse; in general, antidepressants having significant 5-HT2A/2C receptor antagonist properties increase SWS, whereas other drugs, such as SSRIs or MAOIs, either lower SWS or produce no change. Sleep continuity is improved acutely following administration of antidepressants with sedating properties such as certain TCAs, trazodone, and mianserin. Some nonsedating drugs (ritanserin and nefazodone) also improve sleep continuity measures, possibly through 5-HT2A/2C receptor blockade.

Fluoxetine-induced memory impairment in an adolescent

This paper describes a 14-year-old male patient who complained of memory problems during treatment with fluoxetine for major depression. The patient showed impairments on all five scales of the Wechsler Memory Scale-Revised during fluoxetine treatment. Three of the scales, Verbal Memory, Visual Memory, and General Memory, showed statistically significant improvements after fluoxetine was discontinued. This case represents the first time memory deficits related to fluoxetine were quantitated with a standardized memory test. It points to cognitive side effects that need to be understood.

Effect of pulse loading with clomipramine on EEG sleep

Two different initial dosing regimens with clomipramine (CMI) were used to compare early response indicators and dose strategies. Thirty-two inpatients with major depressive disorder were randomized in a double-blind protocol. The pulse-loading group received 150 and 200 mg of CMI on 2 consecutive evenings and then received a placebo for 8 days. The traditional dosing group began at 50 mg of CMI followed by gradual increases every second day until 200 mg was reached. After 10 days, both groups were placed on an adjustable dosing schedule of CMI, initially set at 200 mg, for an additional 2 weeks. Significant drug effects were noted on several sleep parameters demonstrating suppression of rapid eye movement (REM) sleep. In the pulse-loading group, drug responders were found to have a significantly faster and more robust rebound in REM sleep than nonresponders. Both measures of REM activity and REM sleep time showed a significant difference between the groups. In addition, a significant correlation was found between falling levels of the desmethylclomipramine metabolite of CMI and REM sleep activity during the rebound phase. The clinical and theoretical implications of these findings are discussed.

Sleep and suicidality in psychotic patients

The purpose of the study was to determine whether polysomnographic rapid eye movement (REM) sleep parameters distinguish between psychotic patients with and without a history of suicidal behavior. We examined both hand-scored and automated measures of rapid eye movement (REM) sleep in psychotic patients with and without a history of suicidal ideation or attempts. Patients with suicidal behavior had significantly increased REM activity and time both in the whole night data and in the first REM period. These findings suggest an association between REM sleep abnormalities and suicidal behavior, perhaps related to alteration in serotonergic function.

Drugs and the sleep-wakefulness continuum

The circadian cycle of sleep and wakefulness in humans is controlled by the activity of many neurotransmitters. Studies of the effects of drugs on the central nervous system have elucidated some of the mechanisms that may be involved. Some transmitters are concerned with the basic control of sleep and wakefulness, influencing both alertness during the day and the pattern of nocturnal sleep. On the other hand, there are other transmitters that appear to be concerned primarily with the manifestation of wakefulness and vigilance, without a direct role in the process of sleep.

Sleep patterns in depression and anxiety: theory and pharmacological effects

Sleep is invariably disrupted in patients who have depression and in patients with anxiety disorders. Depression and anxiety frequently coexist and are associated with disturbances in various neurotransmitters. The authors explore the relationship between sleep and the two disorders as well as the effects of antidepressants and anxiolytics on sleep architecture. The effects on sleep of various neurotransmitter systems implicated in depression and anxiety are outlined. Lastly, various theoretical models are proposed to account for the above mentioned phenomena and further directions for research are suggested.

A patient with coexisting narcolepsy and morbid jealousy showing favourable response to fluoxetine

A 37 year old Chinese man suffered from coexisting narcolepsy and morbid jealousy which were precipitated by head injury 5 years previously. Fluoxetine 20 mg/day reduced his narcoleptic symptoms and morbid jealousy but not his sleepiness. On defaulting treatment, the patient's symptoms and marital problem recurred. A common central serotonin disturbance might be involved in mediating the sleep disorder and associated psychopathology.

Symposium: Normal and abnormal REM sleep regulation: REM sleep in depression-an overview

Abnormalities of REM sleep, i.e. shortening of REM latency, lengthening of the duration of the first REM period and heightening of REM density, which are frequently observed in patients with a major depressive disorder (MDD), have attracted considerable interest. Initial hopes that these aberrant patterns of sleep constitute specific markers for the primary/endogenous sub-type of depression have not been fulfilled. The specificity of REM sleep disinhibition for depression in comparison with other psychopathological groups is challenged as well. Demographic variables like age and sex exert strong influences on sleep physiology and must be controlled when searching for specific markers of depressed sleep. It is still an open question whether abnormalities of sleep are state- or trait-markers of depression. Beyond baseline studies, the cholinergic REM induction test (CRIT) indicated a heightened responsitivity of the REM sleep system to cholinergic challenge in depression compared with healthy controls and other psychopathological groups, with the exception of schizophrenia. A special role for REM sleep in depression is supported by the well-known REM sleep suppressing effect of most antidepressants. The antidepressant effect of selective REM deprivation by awakenings stresses the importance of mechanisms involved in REM sleep regulation for the understanding of the pathophysiology of depressive disorders. The positive effect of total sleep deprivation on depressive mood which can be reversed by daytime naps, furthermore emphasizes relationships between sleep and depression. Experimental evidence as described above instigated several theories like the REM deprivation hypothesis, the 2-process model and the reciprocal interaction model of nonREM-REM sleep regulation to explain the deviant sleep pattern of depression. The different models will be discussed with reference to empirical data gathered in the field.

[Sleep and biological rhythms in depression. Changes caused by antidepressants]

Sleep in depression is characterized by an increase in the number and duration of awakenings, sleep instability, and SWS decrease. REM sleep occurs earlier. REMs density during the 1st REM period is higher than in normal controls matched in age. Accordingly, sleep in depression is similar to sleep in normal aging. Endogenous depression cannot be distinguished from other types of depression by means of polygraphic criteria. Sleep recordings at the beginning of tricyclic compound treatment could be predictive of clinical response to treatment. Sleep modifications induced by antidepressive drugs are reviewed. Sleep recordings enabled us to formulate several physiopathological hypotheses of depression mechanisms: cholinergic-aminergic hypothesis, phase advance, deficiency of process S. Other hypotheses are reviewed: flattening of a hypothetical circadian rhythm of arousal, depressogenic property of sleep in itself (or only of SWS) or timing delay for the start of sleep. A significant phase advance of biological rhythms (temperature, cortisol) is rarely found. A reduction in the amplitude of rhythms (temperature, TSH, melatonine) is more frequent.

Canine cataplexy is preferentially controlled by adrenergic mechanisms: evidence using monoamine selective uptake inhibitors and release enhancers

Narcolepsy is currently treated with anti-depressants to control REM-related symptoms such as cataplexy and with amphetamine-like stimulants for the management of sleepiness. Both stimulant and antidepressant drugs presynaptically enhance monoaminergic transmission but both classes of compounds lack pharmacological specificity. In order to determine which monoamine is selectively involved in the therapeutic effect of these compounds, we examined the effects of selective monoamine uptake inhibitors and release enhancers on cataplexy using a canine model of the human disorder. A total of 14 compounds acting on the adrenergic (desipramine, nisoxetine, nortriptyline, tomoxetine, viloxazine), serotoninergic (fenfluramine, fluoxetine, indalpine, paroxetine, zimelidine) and dopaminergic (amfonelic acid, amineptine, bupropion, GBR 12909) systems were tested. Some additional compounds interesting clinically but with less pharmacological selectivity, i.e., cocaine, dextroamphetamine, methylphenidate, nomifensine and pemoline, were also included in the study. All compounds affecting noradrenergic transmission completely suppressed canine cataplexy at low doses in all dogs tested, whereas compounds which predominantly modified serotoninergic and dopaminergic transmission were either inactive or partially active at high doses. Our results demonstrate the preferential involvement of adrenergic systems in the control of cataplexy and, presumably, REM sleep atonia. Our findings also demonstrate that canine narcolepsy is a useful tool in assessing the pharmacological specificity of antidepressant drugs.

Presynaptic alpha 2-adrenoceptor function and sleep in man: studies with clonidine and idazoxan

The effects of an alpha 2-adrenoceptor agonist, clonidine and an antagonist, idazoxan, were studied on nocturnal sleep in man. Clonidine increased non-rapid eye movement sleep and idazoxan reduced slow wave sleep and increased awake activity. Changes in the continuity of sleep with clonidine were similar to, and those with idazoxan opposite to, the effects of maprotiline, an inhibitor of the uptake of noradrenaline, used as an active control. These findings support the previous conclusion that raised levels of noradrenaline in the synapse, after inhibition of uptake, lead to increased presynaptic inhibition of release of transmitter in man. However, all three drugs decreased rapid eye movement (REM) sleep and the ratio of REM to nonREM sleep and this is believed to be due to a non-specific upset of the balance of influences which control the appearance of REM sleep.

Dopaminergic transmission and the sleep-wakefulness continuum in man

Modulation of dopaminergic transmission on daytime alertness and performance and on nocturnal sleep were studied in man using 30, 60 and 90 mg pemoline, a dopamimetic drug, and 2, 4 and 6 mg pimozide, a dopamine receptor antagonist. Pemoline lengthened daytime sleep latencies and improved attention, and increased wakefulness during nocturnal sleep. Rapid eye movement (REM) sleep was reduced with 90 mg pemoline, but this was due entirely to increased wakefulness. Pimozide had little effect on overnight sleep, but increased the tendency to fall asleep and impaired performance during the day. These studies suggest that the effects of certain drugs which modulate the activity of neurotransmitters, involved in the control of sleep and wakefulness, may be related to the inherent level of activity of the central nervous system. Modulation of the dopaminergic system can have a profound influence on the manifestation of wakefulness and vigilance, but is unlikely to modify directly the elaboration of REM sleep in man.

Drug effects on REM sleep and on endogenous depression

In earlier work REM sleep deprivation (RSD) by arousals improved endogenous depression. This suggested that drugs producing a similar RSD would have antidepressant activity. The arousal RSD was large, persisted for weeks, and was followed by a REM rebound. We call RSD with these properties arousal-type RSD. The present study reviewed literature from 1962 to 1989 on drug REM sleep effects to examine the hypothesis that drugs producing arousal-type RSD improve endogenous depression. The literature reviewed concerned the REM sleep effects of amine precursors, antidepressants, antihistamines, antipsychotics, barbiturates, benzodiazepines, other hypnotics, drugs affecting cholinergic and noradrenergic neurotransmission, ethanol, lithium and narcotics. Four hundred and sixty-eight relevant papers were read and 215 contributed information that could be used in the review. The findings indicated that all drugs producing arousal-type RSD improved endogenous depression. Four drugs that improved endogenous depression did not produce arousal-type RSD.

Effect of caffeine on physiological sleep tendency and ability to sustain wakefulness at night

Marked sleepiness occurs during typical night shift work hours and this reduced alertness is associated with marked performance deficits. The effect of caffeine (versus placebo) upon sleepiness at night was studied using objective measures of physiological sleep tendency and ability to sustain wakefulness. Both measures show caffeine to reduce sleepiness at a single dose roughly the equivalent of two to four cups of coffee. Despite impressive objective differences in alertness with caffeine, subjects did not consistently differentiate between drug conditions on subjective alertness assessments. The use of CNS stimulants to promote alertness during night shift hours should be considered, particularly for occupations for which alertness is critical.

Clomipramine and EEG sleep in depression

Recent studies with clomipramine (CMI) have demonstrated that a pulse-loading approach is associated with a rapid improvement in symptomatology in the absence of continuous treatment. In the present study, sleep changes were evaluated to ascertain the rapidity of clomipramine's effect on electroencephalographic sleep, especially rapid eye movement (REM) and delta wave sleep measures. Clomipramine produced rapid changes in sleep with reduced sleep continuity and almost complete suppression of REM sleep as well as a redistribution of slow wave sleep. Delta waves during sleep were also found to be shifted to the earlier part of the night and increased in intensity. Spectral analysis revealed an increase in power in the delta frequency range that was correlated with clinical responsiveness. These studies point toward a role for clomipramine in the rapid treatment of depression and confirm that sleep physiology may be a good predictor of antidepressant action.

Modulation of sleep by trimipramine in man

We have studied the acute effect of trimipramine (25, 50 and 75 mg) on nocturnal sleep in 6 young men. Fluoxetine (60 mg) and diazepam (10 mg) were included as controls for the potential changes in sleep measures. Trimipramine reduced awake activity, Stage 1 (drowsy) sleep, and the duration of rapid eye movement (REM) sleep. Non-REM (Stage 2) sleep was increased. Residual effects of trimipramine were present the next morning (9 h after ingestion) with impaired coding ability. The effects of trimipramine on sleep and daytime alertness are consistent with its complex pharmacological profile. Reduced wakefulness and sedation are most likely due to synergism between histamine H1, alpha 1-adrenoceptor, and dopamine receptor antagonism. Anticholinergic activity and possibly blockade of alpha 1-adrenoceptors would disturb the balance of transmitter activities which facilitates the optimal appearance of REM sleep. In this way the effects of trimipramine on nocturnal wakefulness and REM sleep are similar to drugs which inhibit the uptake of noradrenaline.