A preliminary study of the effects of nighttime administration of the serotonin agonist, m-CPP, on sleep architecture and behavior in healthy volunteers

SSRIs in the Treatment of Depression: A Pharmacological CUL-DE-SAC?

The widespread adoption of selective serotonin reuptake inhibitors (SSRIs) as first-line pharmacological treatments in the management of clinical depression transformed the landscape of drug therapy for this condition. SSRIs are safer and better tolerated than the tricyclic antidepressants (TCAs) that they replaced. However, they have limitations that may have placed a ceiling on the expectations of first-line pharmacological treatment. Notable problems with SSRIs include induction of anxiety on treatment initiation, delayed onset of significant therapeutic effect, sexual dysfunction, sleep disturbance and overall modest efficacy. The latter is linked with an inability of SSRIs to effectively treat syndromes of anhedonia and cognitive impairment. Combined serotonin and noradrenaline reuptake inhibitors (SNRIs), such as venlafaxine, have produced some limited improvements over SSRIs in efficacy, at the cost of a greater side-effect burden. Attempts to supplement serotonin reuptake activity with actions at serotonin receptor sub-types have not yet yielded substantial benefits; however, vortioxetine may provide more utility in the management of cognitive impairment. Future advances might come from the development of SNRIs, which more closely mimic the actions of effective TCAs. There may also be possible benefits to be derived from combining SSRIs with 5-HT4 receptor agonists and 5-HT7 receptor antagonists.

Trazodone-induced delirium: case report

Trazodone is used as an antidepressant in doses between 150 and 600 mg. At lower doses, it is commonly used to treat insomnia. There are few case reports about confusional symptoms as an undesirable side effect of this drug. We report a case of a patient who presented with delirium after prescription of trazodone 100 mg. She required hospitalisation but, shortly after discontinuation of trazodone, the symptoms disappeared without antipsychotic medication. Seven months after the episode, the patient remains asymptomatic.

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.

Subjective and objective sleep and self-harm behaviors in young children: a general population study

Significant association between sleep disturbances and suicidal ideation and/or attempts is reported in adults and adolescents. However, there is paucity of studies exploring the association between sleep and self-harm behaviors (SHB) in young children and are limited to only subjective sleep measures. We examined the association between SHB and both subjective and objective sleep in a population-based sample of 5-12 yr old. Parents of every student in 3 local school (K-5) districts (n=7312) was sent a screening questionnaire. Randomly selected children from this sample underwent a comprehensive history, physical examination, a 9-h overnight polysomnogram and completed several questionnaires. Among the final sample (n=693), 27 children had SHB with adjusted prevalence of 3%. There was no difference in age, gender, obesity, or socioeconomic status in subjects with or without SHB. Significantly more children with SHB had subjective sleep difficulty and depression. Difficulty maintaining sleep and frequent nightmares were associated with SHB independent of depression or demographics. Polysomnographic %REM-sleep was significantly higher in the SHB group after adjusting for demographics and depression. These data indicate that parent reported sleep disturbances are independently associated with SHB. It is possible that higher REM-sleep is a non-invasive biomarker for risk of self-harm behaviors in young children.

Sleep and its disorders in translational medicine

The study of sleep is a useful approach to studying the brain in psychiatric disorders and in investigating the effects of psychotropic drugs. Sleep physiology lends itself well to pharmacological and physiological manipulation, as it has the advantage of a functional output, the electroencephalograph, which is common to all mammals, and can be measured in freely moving (or naturally sleeping) animals under controlled laboratory conditions or in a naturalistic home environment. The complexity of sleep architecture varies between species but all share features which are comparable. In addition, sleep architecture is sensitive to changes in brain neurotransmitters such as serotonin, so cross-species sleep measurement can be combined with pharmacological manipulation to investigate the receptor mechanisms controlling sleep-wake regulation and sleep architecture in response to known and novel agents. Translational approaches such as these have improved our understanding of sleep circuitry and facilitated the development of new treatments for sleep disorders, particularly insomnia. This review provides examples of how research findings within the sleep field have been translated between animal models, healthy volunteers and patient populations with particular focus on the serotonergic system.

Sleep and youth suicidal behavior: a neglected field

PURPOSE OF REVIEW

Sleep undergoes substantial changes during adolescence and suicide risk begins to increase during this period as well. This review focuses on recent literature on the relationship between sleep and suicidal behavior and proposes directions for future research.

RECENT FINDINGS

Adolescent sleep is characterized by widespread sleep restriction, irregular sleep schedules, daytime sleepiness, and elevated risk for sleep disturbances. More research on adolescent sleep and psychosocial impairment, psychiatric disorders, and suicidal behavior has been conducted. Suicidal psychiatric patients had more sleep disturbances including insomnia, hypersomnia, or nightmares than nonsuicidal patients. Shorter rapid eye movement latency and increased rapid eye movement activity have been noted to be a marker of suicidality in psychiatric patients. Epidemiological studies have demonstrated that insomnia, nightmares, and sleep insufficiency are associated with elevated risk for suicide. Although the link between insomnia and suicidal behavior appears to be mediated by depression, existing data suggest an independent predictive role of nightmares in future suicidal behavior.

SUMMARY

Sleep loss or disturbances are likely to signal an increased risk of future suicidal action in adolescents. Large-scale prospective studies and neurobiological studies are needed for a better understanding of the complex relationship between sleep, psychopathology, and youth suicidal behavior.

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.

Sleep disturbance and rage attacks in opsoclonus-myoclonus syndrome: response to trazodone

OBJECTIVES

Parents of children with opsoclonus-myoclonus syndrome (OMS) frequently describe poor sleep and rage attacks. We hypothesized that these manifestations are related and could result from underlying monoaminergic dysfunction.

STUDY DESIGN

We clinically characterized the sleep and behavioral characteristics of 51 young children with OMS; 19 of those with the most disruptive sleep patterns were treated with trazodone, a soporific serotonergic agent.

RESULTS

Sleep disturbances, including prolonged sleep latency, fragmented sleep, reduced quantity of sleep, snoring, and non-restorative sleep, were reported in 32 children, and frequent rage attacks were reported in 25. In 59% of the poor sleepers, parents felt that the problem was severe enough to warrant treatment. Children sleeping <10 hours/night had a higher rage frequency than those who slept more. Of the children who required trazodone, 84% were receiving corticosteroids or adrenocorticotropic hormone (corticotrophin), compared with 37% in the subgroup with normal sleep. Trazodone (3.0 +/- 0.4 mg/kg/day) improved sleep and behavior in 95% of the children, significantly increasing total sleep time by 72%, decreasing the number of awakenings by 76%, and reducing rage attacks by 33%.

CONCLUSIONS

Children with OMS exhibited multiple types of sleep disturbances, which contributed to rage attacks. Trazodone was effective in improving sleep and decreasing rage attacks and was well tolerated, even in toddlers.

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.

Sleep-wake effects of meta-chlorophenyl piperazine and mianserin in the behaviorally depressed rat

The present study examined the effects of meta-chlorophenyl piperazine (mCPP) and mianserin on the sleep-wake cycle of the clomipramine-induced behaviorally screened depressed rats. Six-hour polygraphic recordings were made between 06:00 and 12:00 h, after a single injection of either saline or mianserin or mCPP into the lateral cerebral ventricle (i.c.v.) of both the depressed (n=12) and control rats (n=12). The injection of mCPP in the depressed rats caused a significant reduction in the total duration and number of rapid eye movement (REM) sleep episodes while it increased the REM sleep onset latency compared to the control saline injections. The injection of mianserin in the depressed rats also caused a significant reduction in the total duration and number of REM sleep episodes without changing the REM sleep latency. These results demonstrate for the first time that the central administration of mCPP and mianserin could act as an antidepressant in the clomipramine-induced rat model of depression.

Effects of trazodone and imipramine on the biological rhythm: an analysis of sleep EEG and body core temperature

Depression commonly involves abnormalities of the sleep-wake rhythm, the temperature rhythm, and other biological rhythms. The changes of these biological rhythms are caused in remission by medications. However, it has yet to be clarified whether the biological rhythms are changed as a result of recovery from depression or from the direct pharmacological effects of the antidepressants. Therefore, we have undertaken a study on the direct effects of the antidepressants trazodone and imipramine on the biological rhythms of healthy volunteers. The study involved 12 healthy male volunteers (ages 21 approximately 28 years, mean age 23.9+/-1.7 years) who had given written informed consent. Placebo, trazodone, and imipramine were each administered in a single blind manner four times a day, during the three-day study period. The total daily dosage of trazodone was 100 mg (50 mg in one subject), and of imipramine 40 mg (20 mg in one subject). Subjects were submitted to polysomnography (PSG) and body core temperature (rectal temperature) measurements during the study period. We compared the data concerning the antidepressants to those of the placebo. The results show that, with regard to the sleep rhythm, trazodone significantly increased slow wave sleep (SWS), but no changes were observed in REM (rapid eye movement) sleep. Imipramine significantly decreased REM sleep and prolonged the REM cycle. With regard to the temperature rhythm, trazodone showed a tendency to advance the appearance time of the minimal temperature. Imipramine significantly lowered the maximal temperature and decreased the difference between the maximal and the minimal temperature, but no changes in the phases were observed. Neither antidepressant had any effect on the temperature cycle. Trazodone and imipramine showed different effects on PSG. Furthermore, they had different effects on the temperature rhythm. The changes of the sleep-wake rhythm were greater than those of the temperature rhythm. Although the two antidepressants had different mechanisms of action, it is worthy of note that both directly influenced the biological rhythms of healthy volunteers.

Effect of risperidone on sleep in schizophrenia: a comparison with haloperidol

The aim of the present study is to determine the effect of the atypical antipsychotic drug, risperidone on sleep measures in patients with schizophrenia by polysomnography. Sleep measures were compared in five schizophrenic patients who were receiving risperidone alone and five schizophrenic patients who were receiving haloperidol alone. There were no differences between these two groups in their demographic characteristics or doses of antipsychotic medication. The slow wave sleep period was significantly longer in the risperidone-treated group than in the haloperidol-treated group. There were, however, no other significant differences in sleep variables between these groups. This difference in the effect on sleep between risperidone and haloperidol may be due to their differential actions on serotonin (5-HT2) receptors. Risperidone, which is known to be a serotonin-dopamine antagonist, has the potential to improve the quality of sleep in schizophrenic patients.

Sleep and daytime sleepiness the next day following single night-time dose of fluvoxamine, dothiepin and placebo in normal volunteers

To explore the effects of sedating and non-sedating antidepressants, we conducted a placebo-controlled, double-blind cross-over study in 12 normal subjects of the effects of a single night-time dose of fluvoxamine 100 mg, dothiepin 100 mg or placebo on night-time sleep recorded at home, and sleepiness and performance the following day. Night-time sleep was altered significantly by both drugs, with main effects on rapid eye movement (REM) sleep and sleep continuity. Dothiepin increased total sleep time, REM latency and stage 2 sleep and decreased arousals, wake after sleep onset and stage 1, whereas fluvoxamine decreased total sleep time and REM time and increased wake after sleep onset. Sleep latencies in daytime naps were significantly shorter for dothiepin and longer for fluvoxamine, showing that subjects were more sleepy when taking dothiepin. Electroencephalograms (EEG) performed during performance tasks failed to distinguish significantly between drugs. There were no significant differences between groups on our measures of tracking performance or reaction time; however, these tasks were designed primarily to provide a standard setting in which to monitor continuous EEG, and were unsuitable to detect sleepiness effects themselves. Saccadic eye movement velocity, acceleration and deceleration showed small non-significant changes after both drugs. Mood self ratings showed no significant differences among the groups. Subjective measures of night-time sleep reflected the objective measures of sleep continuity, and the items for difficulty and speed of wakening in the morning were significantly higher (i.e. more difficulty and slower) in the dothiepin group. The home-recorded sleep findings after fluvoxamine in this study were very similar to sleep laboratory studies with other antidepressant drugs, thus providing more validation of the home recording method.

Effects of trazodone on polysomnography, blood concentration and core body temperature in healthy volunteers

Polysomnography, blood concentration and core body temperature recordings were performed on 12 healthy volunteers with administration of trazodone and placebo. Trazodone increased slow wave sleep (SWS), and decreased the average, the highest and lowest core body temperature significantly compared to placebo. The blood concentration of trazodone correlated positively with amplitude (the difference between the highest and lowest temperature) and %SWS during the first period of a sleep phase divided into three periods, and negatively with the lowest temperature. The appearance time of the lowest temperature correlated negatively with %SWS.

Selective serotonin reuptake inhibitors in affective disorders--I. Basic pharmacology

The selective serotonin reuptake inhibitors (SSRIs), citalopram, fluoxetine, fluvoxamine, paroxetine and sertraline, are the result of rational research to find drugs that were as effective as the tricyclic antidepressants but with fewer safety and tolerability problems. The SSRIs selectively and powerfully inhibit serotonin reuptake and result in a potentiation of serotonergic neurotransmission. The property of potent serotonin reuptake appears to give a broad spectrum of therapeutic activity in depression, anxiety, obsessional and impulse control disorders. However, despite the sharing of the same principal mechanism of action, SSRIs are structurally diverse with clear variations in their pharmacodynamic and pharmacokinetic profiles. The potency for serotonin reuptake inhibition varies amongst this group, as does the selectivity for serotonin relative to noradrenaline and dopamine reuptake inhibition. The relative potency of sertraline for dopamine reuptake inhibition differentiates it pharmacologically from other SSRIs. Affinity for neuroreceptors, such as sigma1, muscarinic and 5-HT2c, also differs widely. Furthermore, the inhibition of nitric oxide synthetase by paroxetine, and possibly other SSRIs, may have significant pharmacodynamic effects. Citalopram and fluoxetine are racemic mixtures of different chiral forms that possess varying pharmacokinetic and pharmacological profiles. Fluoxetine has a long acting and pharmacologically active metabolite. There are important clinical differences among the SSRIs in their pharmacokinetic characteristics. These include differences in their half-lives, linear versus non-linear pharmacokinetics, effect of age on their clearance and their potential to inhibit drug metabolising cytochrome P450 (CYP) isoenzymes. These pharmacological and pharmacokinetic differences underly the increasingly apparent important clinical differences amongst the SSRIs.

Effects of trazodone hydrochloride and imipramine on polysomnography in healthy subjects

Polysomnography was performed on eight healthy men with trazodone hydrochloride, imipramine and placebo. Trazodone hydrochloride increased slow wave sleep significantly. Imipramine prolonged rapid eye movement (REM) latency and decreased the percentage of REM sleep significantly. Trazodone decreased stages 1 and 2 sleep, while imipramine increased it. These findings suggest that the antidepressive effect of trazodone might be different from that of imipramine with the suppression of REM sleep.

Effects of a tryptophan-free amino acid drink challenge on normal human sleep electroencephalogram and mood

BACKGROUND

Serotonin has been implicated in the regulation of sleep and mood. In animals a tryptophan-free amino acid drink (TFD) challenge has been found to reduce brain serotonin. We hypothesized this TFD would produce alterations in electroencephalographic (EEG) sleep commonly associated with depression, i.e. an enhancement of rapid eye movement (REM) sleep, and adversely affect mood ratings in humans.

METHODS

We investigated the effects of a TFD challenge in 11 healthy male subjects on EEG sleep and mood (assessed by Profile of Mood States). All subjects received on separate occasions an experimental drink containing approximately 100 g of an amino acid mixture (100% TFD) and a control drink containing one fourth strength (25% TFD) of the experimental drink 5 hours prior to sleep (6:00 PM).

RESULTS

Both drinks significantly decreased plasma tryptophan levels 5 hours postchallenge (11:00 PM). Both drinks significantly decreased REM latency, and the 25% TFD also increased REM time and REM% compared to baseline. No significant changes were found in subjective ratings of depression; however, subjects reported confusion and tension and a decrease in elation, vigor, and friendliness compared with baseline.

CONCLUSIONS

These TFD findings further support the involvement of serotonin deficiency in EEG sleep findings commonly seen in depression.

Mirtazapine: pharmacology in relation to adverse effects

Mirtazapine is a new antidepressant that falls into the general class of receptor-blocking drugs rather than being an uptake or enzyme inhibitor. It can be described as a noradrenergic and specific serotonergic antidepressant (NaSSA). The unique pharmacology of mirtazapine means that it has a very different side effect profile from the tricyclic antidepressants, producing less alpha 1 adrenergic and muscarinic blockade, and the selective serotonin reuptake inhibitors (SSRIs) and the serotonin-noradrenaline reuptake inhibitors (SNRIs), causing much less nausea and sexual dysfunction by virtue of its blockade of 5-HT2 and 5-HT3 receptors.

The effects of paroxetine and nefazodone on sleep: a placebo controlled trial

We studied the effect of acute (1 day) and subacute (16 days) administration of the new antidepressant, nefazodone (400 mg daily), and the selective serotonin re-uptake inhibitor (SSRI), paroxetine (30 mg daily), on the sleep polysomnogram of 37 healthy volunteers using a random allocation, double-blind, placebo-controlled design. Compared to placebo, paroxetine lowered rapid eye movement (REM) sleep and increased REM latency. In addition, paroxetine increased awakenings and reduced Actual Sleep Time and Sleep Efficiency. In contrast, nefazodone did not alter REM sleep and had little effect on measures of sleep continuity. We conclude that in contrast to typical SSRIs, nefazodone administration has little effect on sleep architecture in healthy volunteers.

Acute and subchronic effects of nefazodone and imipramine on highway driving, cognitive functions, and daytime sleepiness in healthy adult and elderly subjects

The acute and subchronic effects of two dosages of a new serotonergic antidepressant, nefazodone, and those of the tricyclic imipramine were examined in a double-blind, crossover, placebo-controlled study. Twenty-four healthy subjects from two age groups (12 adults and 12 elderly from both sexes) received the four treatments (nefazodone, 100 and 200 mg twice daily; imipramine, 50 mg twice daily; and placebo) for 7 days with a 7-day washout period. Measurements were performed after the morning doses on day 1 and day 7. These included a standard over-the-road highway driving test, a psychomotor test battery, and sleep latency tests. Blood samples were taken on both days and analyzed to determine concentrations of parent drugs and their major metabolites. The main results showed that the reference drug, imipramine, had a detrimental effect after a single dose on lateral position control in the driving test, primarily in the adult group, that diminished after repeated dosing. Minor impairment on psychomotor test performance was found with both days. On the other hand, a single administration of both doses of nefazodone did not impair highway driving performance (even showed some improvement) and had no or only minor effects on psychomotor performance. After repeated dosing, nefazodone 200 mg twice daily (but not the 100-mg dose) produced slight impairment of lateral position control; dose-related impairment of cognitive and memory functions was found. The effects of nefazodone were generally in the same direction in both age groups. Significant correlations were found between steady-state concentrations of nefazodone in plasma (200-mg, twice-daily condition) as well as imipramine, and reaction time changes in a memory scanning task. Neither drug appeared to induce daytime sleepiness as measured by the sleep latency tests.

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.

Inhibition of REM sleep by ipsapirone, a 5HT1A agonist, in normal volunteers

In order to test the hypothesis that serotonergic mechanisms inhibit REM sleep via a 5HT1A receptor, we administered placebo and ipsapirone (10 and 20 mg by mouth 15 min before bedtime) to ten normal volunteers in a double blind fashion. Ipsapirone is a relatively selective 5HT1A receptor agonist. As predicted, ipsapirone prolonged REM latency and Mean Latency to Eye Movements (M-LEM), a measure of time between onset of REM sleep and the first eye movement of the REM period, and REM% at both doses compared with placebo. It also reduced sleep efficiency and total REM sleep time at the highest dose. These results support the hypothesis that systemic stimulation of 5HT1A receptors prolong REM latency and inhibit REM sleep.

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.

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.

The effects of fenfluramine on sleep and prolactin in depressed inpatients: a comparison of potential indices of brain serotonergic responsivity

The effects of fenfluramine, an indirect serotonergic agonist, on electroencephalographic sleep and prolactin secretion were assessed in 12 unmedicated inpatients with a primary diagnosis of major depressive episode. Compared to prefenfluramine profiles, sleep studies performed following fenfluramine administration showed a statistically significant reduction of slow-wave sleep (SWS) (p < 0.001) and a corresponding increase in percentage of stage-2 sleep (p < 0.007). Automated delta wave counts per min decreased significantly during the first nonrapid eye movement (NREM) period (p = 0.04), and automated rapid-eye movement (REM) counts were also decreased in the second REM period (p = 0.02). These effects on sleep electroencephalogram (EEG) did not correlate significantly with another measure of serotonergic responsivity, namely peak prolactin level following fenfluramine, nor with the severity of depression. The reductions in SWS and REM counts are proposed to be the result of time-dependent changes in serotonergic neurotransmission following the administration of fenfluramine. These findings are consistent with earlier work suggesting a role for serotonin in initiation and regulation of SWS and REM sleep.

Mono N-aryl ethylenediamine and piperazine derivatives are GABAA receptor blockers: implications for psychiatry

Ethylenediamine (EDA) and piperazine are known GABA-A receptor agonists and this activity appears to reside in their carbamate adducts. In CO2-free incubation medium EDA and piperazine weakly reverse the inhibitory action of 1 microM GABA on specific [35S]t-butylbicyclophosphorothionate (35S-TBPS) binding to rat brain membranes in vitro. In 25 mM sodium bicarbonate buffer, EDA and piperazine much more potently inhibit 35S-TBPS binding in a way reversible by the GABA-A receptor blocker R5135. Thus, native EDA and piperazine are weak GABA-A receptor blockers, while their presumed carbamate adducts, formed by reaction with bicarbonate, are more potent GABA-A receptor agonists. Virtually all structural modifications of EDA or piperazine result in GABA-A receptor blockers, even in the presence of bicarbonate, judging from their abilities to fully or partially reverse the inhibitory effect of GABA on 35S-TBPS binding. Of 12 non-aromatic piperazine or EDA derivatives, the piperazine derivatives are the more potent GABA antagonists, although all are weak compared to the mono N-aryl derivatives. Nineteen mono N-aryl EDA derivatives are moderately potent GABA antagonists, including 10 with demonstrated or potential antidepressant activity. Most of the N-aryl piperazines are moderately to highly potent GABA antagonists, one (pitrazepin) being 4 to 5 times more potent than bicuculline. There are several clinically effective antidepressants (e.g. Amoxapine, Mianserine) and antipsychotics (Clothiapine, Loxapine, Metiapine, Clozapine and Fluperlapine) among the more potent N-aryl piperazine GABA antagonists.(ABSTRACT TRUNCATED AT 250 WORDS)

Sleep and dreaming: induction and mediation of REM sleep by cholinergic mechanisms

The most important recent work on the neurobiology of sleep has focused on the precise cellular and biochemical mechanisms of rapid eye movement sleep mediation. Direct and indirect evidence implicates acetylcholine-containing neurons in the peribrachial pons as critical in the triggering and maintenance of rapid eye movement sleep. Other new studies provide support for the hypothesis that the cholinergic generator system is gated during waking by serotonergic and noradrenergic influences. A growing consensus regarding the basic neurobiology has stimulated new thinking about the brain basis of consciousness during waking and dreaming.

Nocturnal growth hormone secretion in schizophrenic patients and healthy subjects

Plasma growth hormone concentrations were measured at hourly intervals between 10 p.m. and 8 a.m. the next morning in 15 drug-free chronic schizophrenic male inpatients and 14 healthy males. Growth hormone secretion was significantly lower in the patients as compared with the controls. Growth hormone release peaked around 1 a.m. in the controls, but a growth hormone peak was absent in the patient group. Increased dopamine activity, increased serotonin activity, or both could explain the absence of a nocturnal growth hormone surge in the schizophrenic patients.

m-Chlorophenylpiperazine as a probe of serotonin function

m-Chlorophenylpiperazine (mCPP) is the most extensively used probe of serotonin function in psychiatry. This article reviews its in vitro and in vivo properties in animals, normal human subjects, and psychiatric patients. mCPP is a safe, reliable, direct 5-hydroxytryptamine (5HT) agonist, which may be used to evaluate 5HT receptor sensitivity. It causes a consistent, dose-dependent elevation of ACTH, cortisol, and prolactin levels in both animals and humans, as well as increased body temperature in man. It also causes a variety of behavioral effects, depending on the population studied. These effects are probably 5HT receptor-related, although specific 5HT receptor subtype mechanisms have not yet been established. mCPP may be considered an important addition to armamentarium of 5HT receptor probes, which is especially useful until more selective 5HT receptor agonists have been tested.