Differential effects of amitriptyline and of zimelidine on the sleep electroencephalogram of depressed patients

Depression and Sleep

Impaired sleep is both a risk factor and a symptom of depression. Objective sleep is assessed using the sleep electroencephalogram (EEG). Characteristic sleep-EEG changes in patients with depression include disinhibition of rapid eye movement (REM) sleep, changes of sleep continuity, and impaired non-REM sleep. Most antidepressants suppress REM sleep both in healthy volunteers and depressed patients. Various sleep-EEG variables may be suitable as biomarkers for diagnosis, prognosis, and prediction of therapy response in depression. In family studies of depression, enhanced REM density, a measure for frequency of rapid eye movements, is characteristic for an endophenotype. Cordance is an EEG measure distinctly correlated with regional brain perfusion. Prefrontal theta cordance, derived from REM sleep, appears to be a biomarker of antidepressant treatment response. Some predictive sleep-EEG markers of depression appear to be related to hypothalamo-pituitary-adrenocortical system activity.

Insomnia in hospitalized psychiatric patients: prevalence and associated factors

OBJECTIVES

To quantify and describe the prevalence of insomnia in hospitalized psychiatric patients and to investigate the associations between insomnia and demographic and clinical factors in hospitalized psychiatric patients.

METHODS

The participants included 203 individuals hospitalized for psychiatric treatment at an academic medical center. Demographic information, psychiatric diagnoses, current psychotropic medication use, and history of substance use were collected. Insomnia screening was performed using the Insomnia Severity Index. Depressive and anxiety symptoms were also evaluated using the Generalized Anxiety Disorder questionnaire and the Patient Health Questionnaire. Restless legs syndrome (RLS) symptoms were evaluated using the Restless Legs Syndrome Rating Scale (RLSRS). Statistical analysis was conducted to detect the prevalence of insomnia among the participants and to examine possible associations among psychiatric disorders, psychotropic medications, and RLS.

RESULTS

Out of the 203 participants that completed the survey, 67.4% were found to have insomnia and 14.3% were found to have RLS. The severity of insomnia was found to be associated with the presence of RLS, depressive and anxious symptomatology, suicidal ideation, use of selective serotonin reuptake inhibitors, and use of benzodiazepines.

Adverse Effects of Psychotropic Medications on Sleep

Psychotropic medications such as antidepressants, antipsychotics, stimulants, and benzodiazepines are widely prescribed. Most of these medications are thought to exert their effects through modulation of various monoamines as well as interactions with receptors such as histamine and muscarinic cholinergic receptors. Through these interactions, psychotropics can also have a significant impact on sleep physiology, resulting in both beneficial and adverse effects on sleep.

The Neurobiological Mechanisms and Treatments of REM Sleep Disturbances in Depression

Most depressed patients suffer from sleep abnormalities, which are one of the critical symptoms of depression. They are robust risk factors for the initiation and development of depression. Studies about sleep electroencephalograms have shown characteristic changes in depression such as reductions in non-rapid eye movement sleep production, disruptions of sleep continuity and disinhibition of rapid eye movement (REM) sleep. REM sleep alterations include a decrease in REM sleep latency, an increase in REM sleep duration and REM sleep density with respect to depressive episodes. Emotional brain processing dependent on the normal sleep-wake regulation seems to be failed in depression, which also promotes the development of clinical depression. Also, REM sleep alterations have been considered as biomarkers of depression. The disturbances of norepinephrine and serotonin systems may contribute to REM sleep abnormalities in depression. Lastly, this review also discusses the effects of different antidepressants on REM sleep disturbances in depression.

Wake and sleep EEG provide biomarkers in depression

Both wake and sleep electroencephalogram (EEG) provide biomarkers of depression and antidepressive therapy, respectively. For a long time it is known that EEG activity is altered by drugs. Quantitative EEG analysis helps to delineate effects of antidepressants on brain activity. Cordance is an EEG measure with a superior correlation with regional brain perfusion. Prefrontal quantitative EEG cordance appears to be a predictor of the response to antidepressants. Sleep EEG shows characteristic changes in depression as impaired sleep continuity, desinhibition of REM sleep and changes of nonREM sleep. Elevated REM density (a measure for frequency of rapid eye movements) characterizes an endophenotype in family studies of depression. REM-sleep changes including a more distinct REM rebound after sleep deprivation are found in animal models of depression. Most antidepressants suppress REM sleep in depressed patients, normal controls and laboratory animals. REM suppression appears to be a distinct, but not an absolute requirement for antidepressive effects of a compound. Sleep-EEG variables like REM latency or certain clusters of variables were shown to predict the response to the treatment with a certain antidepressant or even the course of the disorder for several years. Some of these predictive sleep-EEG markers of the longterm course of depression appear to be closely related to hypothalamo-pituitary-adrenocortical system activity.

Contribution of sleep research to the development of new antidepressants

Several sleep anomalies are known to accompany depression and other psychiatric disorders, and to be partially modified by drugs efficient on clinical symptoms. Many puzzling theoretical questions remain, even after 30 years of research, because these drugs do not act in a uniform way: some reduce slow-wave sleep while others increase it; some prolong rapid-eye movement sleep latency while others do not. The relationship between insomnia and depression is likely to be a close one, since a large majority of patients with depression suffer insomnia, and that insomnia can predate depression by a few years. However, questions remain here, too, since sleep deprivation is also an effective means to combat depression, and some patients present with hypersomnia rather than insomnia. This review details the action of all current classes of antidepressants on sleep. It examines the predictive value of baseline electronencephalographic sleep symptoms or early modifications due to treatment for eventual clinical efficiency. We will also discuss the two main theories on the relationship between sleep and depression. The action on sleep of all new drugs- and antidepressants in particular - is carefully examined during development, for insomnia is currently considered to be a major health concern in industrialized countries.

Sleep laboratory study on single and repeated dose effects of paroxetine, alprazolam and their combination in healthy young volunteers

AIMS

To evaluate the potential interaction of 20 mg paroxetine and 1 mg alprazolam (early morning once-daily administration) on polysomnographic (PSG) sleep and subjective sleep and awakening quality, both after a single intake and after reaching a steady-state concentration.

METHODS

Twenty-two (11 for the PSG) healthy young volunteers of both sexes with no history of sleep disturbances (Pittsburgh Sleep Quality Index <5) participated in a double-blind, double-dummy, placebo-controlled, repeated-dose, 4-period, cross-over study. All volunteers received all 4 treatment sequences: paroxetine-alprazolam placebo (PAP); paroxetine placebo-alprazolam (PPA); paroxetine-alprazolam (PA), and paroxetine placebo-alprazolam placebo (PLA), in a randomized order. Each treatment was administered over 15 consecutive days, with a treatment-free interval of 7 days prior to the subsequent study period. In each experimental period, one PSG sleep study was performed on the 1st night (single-dose effects) and another study was performed on the 15th night (repeated-dose effects). Additionally, two other PSG studies were assessed: an adaptation recording, and a control night recording. All-night PSG recordings were obtained following standard procedures. Each 30-second period was scored according to the criteria of Rechtschaffen and Kales by means of an automatic sleep analysis system: Somnolyzer 24x7. A self-rating scale for sleep and awakening quality and early morning behavior was completed no later than 15 min after awakening over the 15 days of each experimental intervention. General lineal models (treatment/time) were applied separately to each variable.

RESULTS

(1) No significant effects were observed in any sleep variables when control nights were compared with the 1st night with PLA. (2) Sleep continuity: After PAP a clear awakening effect was seen both in the first and second evaluations, mainly in wake time, movement time, number of awakenings and stage-1 duration. After PPA an evident hypnotic effect was observed on night 1. This effect was mainly observed in maintenance variables and slightly in sleep initiation variables; it had decreased by night 15. After PA an intermediate behavior in the variables related to sleep continuity was seen, highlighting the absence of the tolerance phenomenon observed when PPA was administered alone. (3) Sleep architecture: The most important effects in REM sleep were observed after PAP; an increase in REM latency and decreases in REM sleep. PAP also induced decreases in the number of non-REM and REM periods and increases in the average duration of non-REM periods and sleep cycles. PA presented a similar pattern to PAP, and PPA similar to PLA. In relation to non-REM sleep, PA showed more stage-2 and less slow-wave sleep (SWS). (4) Subjective perception: No significant differences were observed between treatments while they were being taken, but impairments in subjective sleep quality, awaking quality, latency and efficiency were seen, mainly after PA but also after PPA discontinuations.

CONCLUSION

The combination of PAP and PPA presented an intermediate pattern in relation to sleep continuity, with less awaking effect than PAP alone and less hypnotic effect than PPA alone, and without developing tolerance. The PAP and PPA combination also showed a similar effect to PAP on REM sleep and was the treatment with the longest stage 2 and shortest SWS. No subjective sleep and awakening effects were seen during drug intake but subjective withdrawal reports were seen after abrupt interruption. The high agreement rate for the epoch-by-epoch comparison between automatic and human scoring confirms the validity of the Somnolyzer 24x7 and thus facilitates sleep studies in neuropsychopharmacological research.

Effects of sertraline on sleep architecture in patients with depression

Previous studies indicate that selective serotonin reuptake inhibitors (SSRIs), including fluoxetine, fluvoxamine, citalopram and paroxetine, suppress rapid eye movement sleep, and increased nocturnal arousals. There has been no published report of the impact of sertraline on the sleep of depressed patients. This study examines such effects. Forty-seven patients with major depressive disorder, randomized to double-blind treatment with sertraline or placebo, completed sleep studies before and after 12 weeks of pharmacotherapy. Groups were compared using multivariate analyses of covariance and/or analyses of covariance to examine 4 empirically defined sets of sleep measures. Compared to the placebo-treated group, patients who received sertraline experienced an increase in delta wave sleep in the first sleep cycle and prolonged rapid eye movement (REM) sleep latency. Although, sertraline therapy decreased the average number of REM periods (from 3.86 to 2.40), the activity of both REM period 1 and REM period 2 was significantly increased. Aside from an increase in sleep latency, sertraline therapy was not associated with a worsening of measures of sleep continuity. There was also no significant difference between the groups on a measure of subjective sleepiness. These findings are both similar and different from those observed in previous studies of other SSRIs. The increase in delta sleep ratio and consolidation of REM sleep may have some other clinical implications. However, the generalizability of these findings is limited because of a number of reasons. Further studies are needed to examine the effects of SSRIs in acute treatment of depressed patients with severe insomnia, and the relationship of acute changes and relapse prevention of recurrent depression.

Depression, sleep physiology, and antidepressant drugs

This review summarizes current findings regarding effects of antidepressant compounds on sleep architecture and interprets their clinical relevance. Effects of the major classes of antidepressant drugs on sleep properties are presented, with the antidepressant compounds organized into categories based primarily on their putative mechanism of action. The majority of antidepressant compounds, across several different categories, exhibit robust suppression of REM sleep. Others, such as bupropion and nefazodone, lack REM suppressant effects. Such findings support the idea that critical neurochemical mechanisms involved in the regulation of discrete sleep stages can be elucidated by means of polysomnographic investigations utilizing pharmacologically targeted agents. Clinicians have appreciated the importance of antidepressant drug effects on sleep when considering therapeutic options for patients. While such decisions in the past were based on empirical observations, an increasing amount of information regarding specific effects of different antidepressant drugs on sleep continuity and sleep architecture is available. Thus, clinicians may choose to consider profiles of sleep effects for different antidepressant drugs in the initial selection of an antidepressant compound.

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.

Physiological effects of electroconvulsive therapy and transcranial magnetic stimulation in major depression

Major depressive episodes are associated with dysregulation of various physiologic systems. Antidepressant medications alter regulation of the hormonal and sleep systems. A thorough understanding of these changes may elucidate the pathophysiologic basis of the disorder [Amsterdam et al., 1989: Psychoneuroendocrinology 14:43-62], and interventions targeted directly at these systems are being increasingly recognized as possible treatments for depression [Wong et al., 2000: Proc Natl Acad Sci USA 97:325-330; Szuba et al., 1996: Proc Am Coll Neuropsychopharmacol Ann Meet]. These physiologic systems are regulated by the major neurotransmitters implicated in the etiology of mood disorders--norepinephrine, serotonin, and dopamine. Many of the hormones of import for this article also act as neurotransmitters and thus alter cerebral activity themselves [Owens and Nemeroff, 1993: Ciba Found Symp 172:296-308; Weitzner, 1998: Psychother Psychosom 67:125-132]. Parenteral infusion of hydrocortisone [DeBattista, 2000: Am J Psychiatry 157:1334-1337] and thyrotropin-releasing hormone (TRH) [Prange et al., 1972: Lancet 2:999-1002; Marangell et al., 1997: Arch Gen Psychiatry 54:214-222; Szuba, 1996: Proc Am Coll Neuropsychopharmacol Ann Meet.] produce acute antidepressant effects. Antagonists to corticotropin-releasing hormone and repeated parenteral infusion of TRH may have antidepressant activity when given during several weeks [Wong, 2000: Proc Natl Acad Sci USA 97:325-330; Arborelius et al., 1999: J Endocrinol 160:1-12; Callahan et al., 1997: Biol Psychiatry 41:264-272]. Manipulations of the sleep system through sleep deprivation can ameliorate depression [Szuba et al., 1994: Psychiatry Res 51:283-295; see Wirz-Justice et al., 1999: Biol Psychiatry 46:445-453 for review]. Sleep deprivation has been shown in more than three dozen studies published in the last three decades to produce marked, acute antidepressant effects in the majority of depressed individuals [Wirz-Justice, et al., 1999: Biol Psychiatry 46:445-453]. Thus, examination of the effects the two nonpharmacologic treatments, electroconvulsive therapy (ECT) and transcranial magnetic stimulation (TMS), produce in these physiologic systems may help elucidate their mechanisms of action, while enhancing understanding of the neurobiology of depressive illness. We will review these physiologic changes associated with depression, the effects that manipulations of these systems can have on depressive disorders, and then describe the effects the two techniques that can stimulate the human brain in vivo, ECT and TMS, exert on these systems.

The effects of antidepressants on sleep in patients with depression

This paper reviews sleep disturbances in patients with major depressive disorders and the effects of different classes of antidepressants on sleep. It is clear from the studies reviewed that not all antidepressants improve sleep, and, indeed, some worsen sleep disturbances in patients with depression. Whether sleep is improved or further disrupted is of high clinical significance, because persistent sleep problems elevate the risk of relapse, recurrence, or suicide, as well as the need for augmenting medications.

The effects of nefazodone on sleep in depressed patients and healthy controls

This paper briefly reviews the effects of antidepressants on sleep, and highlights recent studies on the effects of nefazodone on sleep in healthy adults and those with major depressive disorders. Studies indicate significant improvement in sleep quality, decreased light sleep, and a reduction in nocturnal awakenings on nefazodone with minimal effect on REM sleep. The clinical relevance of these sleep findings is also discussed.

The link between sleep and depression: the effects of antidepressants on EEG sleep

The assumption that sleep dysregulation is more than a mere epiphenomenon of depression is based on several observations: sleep disturbances are strongly associated with the depressive state; a number of sleep manipulations can alleviate symptoms of depression in some patients; and the majority of antidepressants bring about remarkable changes in sleep polygraphic variables. An obvious question is whether changes in sleep physiological processes are intimately involved in the pathogenesis and recovery from depression. One way to elucidate the link between sleep and depression is to examine whether the influence of antidepressants on sleep is related to clinical improvements in depressives. For that purpose, the effects of antidepressants on EEG sleep and their importance for the treatment of depression are summarized against the background of two existing hypotheses concerning the link between sleep and depression: one hypothesis concerning the role of REM; the other concerning the role of non-REM sleep. EEG sleep studies on the use of antidepressants in depressives have not produced clear evidence of the involvement of REM sleep or non-REM sleep in the mechanisms underlying clinical change. Furthermore, the role of sleep physiological mechanisms during treatment with antidepressants is still unclear. To interpret the effects of antidepressants on EEG sleep in terms of sleep physiological processes more fundamental sleep research is necessary. Also, more comparative studies of antidepressants with similar therapeutic effects but different pharmacological profiles are needed in both healthy and depressed subjects to further quantify the impact of EEG sleep modification in the recovery from depression and to differentiate between pharmacological and sleep-related aspects.

Estimation of the time course of slow-wave sleep over the night in depressed patients: effects of clomipramine and clinical response

The distribution of slow-wave activity during sleep has been analyzed using a method related to the two-process model of sleep regulation. This method is applied to the analyses of data collected from 21 inpatients with unipolar depression who received the antidepressant clomipramine (CMI) in a pulse-loading protocol. CMI infusion was found to redistribute slow-wave activity, producing more concentration in the early part of the night, and also significantly reduced the fluctuation in slow-wave power as a function of time. These measures also distinguished clinical responders from the nonresponders. Drug responders had a significant redistribution of slow-wave activity to the earlier part of the night as compared to nonresponders. This suggests that measures of the distribution of slow-wave activity over the night may represent a good measure of clinical response to antidepressant therapy and have implications for the interpretation of the two-process model and sleep in depression.

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.

Persistent effects of antidepressants: EEG sleep studies in depressed patients during maintenance treatment

Electroencephalographic (EEG) sleep studies represent a research tool that can be used to examine depressed patients over different phases of their illness. We examined the long-term effects of imipramine on EEG sleep in 27 subjects who completed 3 years of maintenance treatment on imipramine without experiencing a recurrence. The analyses were performed on EEG sleep data collected prior to acute treatment, after 3 months in maintenance, and every 3 months thereafter. The major aim was to examine specific changes in rapid eye movement (REM) and slow-wave sleep (SWS) as they unfolded over the course of illness and recovery during long-term drug maintenance. The acute changes in the sleep profile produced by antidepressants remained essentially the same throughout the entire period of drug administration. The REM sleep parameters, which were affected immediately, remained essentially unchanged thereafter, even as long as 3 years into maintenance treatment. A rapid redistribution of slow-wave sleep in the first part of the night was also observed without an increase in the total amount of slow-wave sleep throughout the night. The application of spectral analysis confirmed that the sleep changes following drug administration remained stable throughout all phases of drug treatment. Thus, it appears that sustained clinical improvement is accompanied by persistent sleep alterations on tricyclic antidepressant medication.

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.

Effects of chronic treatment with two selective 5-HT2 antagonists on sleep in the rat

The effect of chronic administration of 2(2-dimethylaminoethylthio)-3-phenylquinoline (ICI-169,369) and 2(2-dimethylamino-2-methylpropylthio)-3-phenylquinoline (ICI-170,809), two selective 5-HT2 antagonists, on sleep was studied in rats. As previously shown, the acute effect of ICI-170,809 was to increase latency to rapid eye movement sleep (REMS), decrease the number of REM periods (REMPs), suppress the cumulative amount of REMS over 12 h, and increase the duration of REMPs in the first 6 h, while having no effect on non-REM sleep (NREMS). Administration of ICI-169,369 had similar effects except no change was seen in the duration of REMPs and cumulative REMS was suppressed for 24 h. When given 2 x daily for 5 days, tolerance to the REMS suppressant effects developed in both drugs. After discontinuation of treatment, a REMS rebound occurred after ICI-170,809, but not ICI-169,369. No significant effect on NREMS was seen after administration of ICI-170,809, whereas ICI-169,369 lowered 24-h cumulative NREMS on the fifth day of administration.

Fluvoxamine versus desipramine: comparative polysomnographic effects

Electroencephalogram sleep measures over a 4-week period were obtained on 35 inpatients with major depression (unipolar) who received either fluvoxamine or desipramine in a randomized double-blind trial. Fluvoxamine showed immediate rapid eye movement (REM) sleep suppression and an alerting effect on sleep continuity measures. In contrast, desipramine administration was associated with REM suppression and sleep continuity improvement. The "alerting" quality of fluvoxamine, similar to other serotonergic antidepressants, appears to be unrelated to a lack of clinical efficacy, but may be related to persistent REM sleep suppression. However, it is premature to comment on the serotonin specificity for REM sleep.

REM sleep suppression by monoamine reuptake blockade: development of tolerance with repeated drug administration

Drugs that block monoamine reuptake initially suppress rapid eye movement (REM) sleep in the cat and other species. Less is known about the effects of repeated drugs administration. Desipramine (DMI) and sertraline [1S,4S-N-methyl-4-(3,4-dichlorophenyl)-1,2,3,4-tetrahydro-1 -naphthylamine] (SER), which are relatively specific in blocking norepinephrine and serotonin reuptake, respectively, were each given to cats for approximately two and a half weeks. Six-hour sleep polygraphic records were obtained under the placebo condition, after acute drug administration, and again during chronic drug administration. DMI and SER both reduced REM sleep percentage acutely and in each case. Significant tolerance then developed. These actions of DMI and SER reflected changes in mean REM sleep episode duration as well as REM sleep episode number. Such differential effects of acute and chronic monoamine reuptake blockade on REM sleep behavior in the cat may ultimately be correlated with pharmacological changes at the receptor level.

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.

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.

Neurophysiological factors in depression: new perspectives

Within the last decade, the application of neurophysiological and neuroendocrine techniques has led directly to the identification of specific psychobiological correlates of depression. More recent efforts have attempted to establish linkages between mechanisms of action by antidepressants and such psychobiological factors. EEG sleep investigations, conducted with various antidepressants, have focused on the "specificity" of REM suppression or slow-wave sleep alterations. To date, results point to a greater commonality of action for REM suppression, lack of sedative effect as a necessary condition for clinical improvement, and the need for greater emphasis on slow-wave sleep research in relation to clinical recovery. The need for integrated theories of neurophysiological and neuroendocrine factors in depression is stressed.

Comparison of effects of desipramine and amitriptyline on EEG sleep of depressed patients

Despite their widespread use, there are few data concerning the effects of tricyclic antidepressants on EEG sleep in depression. The present study documented the effects of desipramine (DMI, n = 17) and amitriptyline (AT, n = 16) upon EEG sleep in hospitalized depressed patients as part of a double-blind protocol involving 28 days of active treatment. Compared to placebo, patients receiving DMI showed somewhat worsened sleep continuity, particularly after 1 week of administration when the dose was 150 mg/day. On the other hand, sleep architecture and REM measures showed a rapid suppression of REM sleep, and then partial tolerance for this effect was observed with continued administration of DMI for 3 weeks. DMI was a more potent suppressor of REM sleep, while AT was more sedative. Based on these differences in effects upon EEG sleep, a discriminant function was derived and resulted in a correct classification of 87.5% of AT cases and 76.5% of DMI cases. These results are discussed in terms of the differences in pharmacological profiles for uptake blockade and anticholinergic potency for these two compounds.