Neuroendocrinological investigations during sleep deprivation in depression. I. Early morning levels of thyrotropin, TH, cortisol, prolactin, LH, FSH, estradiol, and testosterone

Proceedings of the Sleep and Epilepsy Workgroup: Section 2 Comorbidities: Sleep Related Comorbidities of Epilepsy

Epilepsy is a chronic disease with multiple, complex comorbidities. Bidirectional relationships exist among seizures, sleep, circadian rhythms, and diseases within and outside of the central nervous system. Seizures fragment sleep and can contribute to development of sleep disorders, which in turn leads to worse overall health and more seizures. Moreover, treatment options are often limited by interactions with anti-seizure medications. Advances in the fields of epilepsy and in sleep medicine have been made separately, and therefore treating patients with these comorbidities necessitates interdisciplinary approach. The focus of this section of the Sleep and Epilepsy Workgroup was to identify methods of collaboration and outline investigational, educational, and treatment priorities to mutually advance what we consider a combined field.

Determinants of prolactin in postmenopausal Chinese women in Singapore

PURPOSE

Mechanistic and observational data together support a role for prolactin in breast cancer development. Determinants of prolactin in Asian populations have not been meaningfully explored, despite the lower risk of breast cancer in Asian populations.

METHODS

Determinants of plasma prolactin were evaluated in 442 postmenopausal women enrolled in the Singapore Chinese Health Study, a population-based prospective cohort study. At baseline all cohort members completed an in-person interview that elicited information on diet, menstrual and reproductive history, and lifestyle factors. One year after cohort initiation we began collecting blood samples. Quantified were plasma concentrations of prolactin, estrone, estradiol, testosterone, androstenedione, and sex hormone-binding globulin (SHBG). Analysis of covariance method was used for statistical analyses with age at blood draw, time since last meal, and time at blood draw as covariates.

RESULTS

Mean prolactin levels were 25.1% lower with older age at menarche (p value = 0.001), and 27.6% higher with greater years between menarche and menopause (p value = 0.009). Prolactin levels were also positively associated with increased sleep duration (p value = 0.005). The independent determinants of prolactin were years from menarche to menopause, hours of sleep, and the plasma hormones estrone and SHBG (all p values < 0.01).

CONCLUSION

The role of prolactin in breast cancer development may involve reproductive and lifestyle factors, such as a longer duration of menstrual cycling and sleep patterns.

Relationship between Duration of Sleep and Hypertension in Adults: A Meta-Analysis

OBJECTIVES

Epidemiologic studies have shown that chronic short sleep may be associated with the development of hypertension; however, the results are controversial. This meta-analysis was conducted to determine whether the duration of sleep is associated with hypertension.

METHODS

Reference databases (PubMed, EmBase, the Cochrane Library, Chinese Biological Medicine database) were searched for studies related to sleep duration and hypertension. Sleep duration categories (≤ 5 h, 6 h, 7 h, 8 h, ≥ 9 h) and prevalence or incidence of hypertension in each sleep category were extracted. A general analysis and subgroup analyses stratified by gender, age, study design, and different definitions of sleep duration were conducted to evaluate the relationship between sleep duration and hypertension.

RESULTS

Thirteen articles out of a total of 1,628 articles involving 347,759 participants met the inclusion criteria. A U-shaped change in pooled odds ratios (ORs) for hypertension due to the change of sleep duration was observed. The unadjusted OR for hypertension of individuals who slept ≤ 5 h vs. 7 h was 1.61, 95% CI = 1.28-2.02; those who slept ≥ 9 h vs. 7 h was 1.29, 95% CI = 0.97-1.71. The pooled ORs were still significant after adjusted by age and gender. Women deprived of sleep (sleep time ≤ 5 h vs. 7 h, OR = 1.68, 95% CI = 1.39-2.03) had a higher risk of hypertension than men (OR = 1.30, 95% CI = 0.93-1.83).

CONCLUSION

Excessively longer and shorter periods of sleep may both be risk factors for high blood pressure; these associations are stronger in women than men.

Sleep, sleep disturbance, and fertility in women

Sleep and sleep disturbances are increasingly recognized as determinants of women's health and well-being, particularly in the context of the menstrual cycle, pregnancy, and menopause. At present, however, little is known about whether fertility is affected by sleep quantity and quality. That is, to what degree, and by what mechanisms, do sleep and/or its disturbances affect fertility? The purpose of this review is to synthesize what is known about sleep disturbances in relation to reproductive capacity. A model is provided, whereby stress, sleep dysregulation, and circadian misalignment are delineated for their potential relevance to infertility. Ultimately, if it is the case that sleep disturbance is associated with infertility, new avenues for clinical intervention may be possible.

Mood and metabolic consequences of sleep deprivation as a potential endophenotype' in bipolar disorder

It has been commonly recognized that circadian rhythm and sleep/wake cycle are causally involved in bipolar disorder. There has been a paucity of systematic research considering the relations between sleep and mood states in bipolar disorder. The current study examines the possible influences of sleep deprivation on mood states and endocrine functions among first-degree relatives of patients with bipolar disorder and healthy controls. Blood samples were taken at two time points in the consecutive mornings at predeprivation and postdeprivation periods. Participants simultaneously completed the Profiles of Mood States at two time points after giving blood samples. Plasma T3 and TSH levels increased after total sleep deprivation in both groups. Sleep deprivation induced TSH levels were reversely associated with depression-dejection among healthy controls. A paradoxical effect was detected for only the first-degree relatives of the patients that changes in plasma cortisol levels negatively linked to depression-dejection and anger-hostility scores after total sleep deprivation. Plasma DHEA levels became correlated with vigor-activity scores after sleep deprivation among first-degree relatives of bipolar patients. On the contrary, significant associations of depression-dejection, anger-hostility, and confusion-bewilderment with the baseline plasma DHEA levels became statistically trivial in the postdeprivation period. Findings suggested that first-degree relatives of patients with bipolar disorder had completely distinct characteristics with respect to sleep deprivation induced responses in terms of associations between endocrine functions and mood states as compared to individuals whose relatives had no psychiatric problems. Considering the relationships between endocrine functions and mood states among relatives of the patients, it appears like sleep deprivation changes the receptor sensitivity which probably plays a pivotal role on mood outcomes among the first-degree relatives of patients with bipolar disorder.

Sleep timing may modulate the effect of sleep loss on testosterone

BACKGROUND

Sleep loss has been shown to reduce secretory activity of the pituitary-gonadal axis in men, but the determinants of this effect are unknown.

OBJECTIVE

To discriminate the effects of sleep duration and sleep timing on serum concentrations of luteinizing hormone (LH), testosterone (T) and prolactin (PRL).

METHODS

Fifteen young, healthy men (27·1 ± 1·3 years; BMI, 22·9 ± 0·3 kg/m(2) ) were examined in a condition of sleep time restriction to 4 h (bedtime, 02:45 -07:00 h) for two consecutive nights and in a control condition of 8 h regular sleep (bedtime, 22:45-07:00 h). After the second night, serum concentrations of LH, T and PRL were monitored over a 15-h period. In addition, these hormones were measured in serum samples obtained in a further experiment in eight healthy men (24·5 ± 1·1 years; BMI, 23·7 ± 0·6 kg/m(2) ) in the morning after one night of total sleep deprivation, of 4·5 h sleep (bedtime, 22:30-03:30 h), and of regular 7 h sleep (bedtime, 22:30-06:00 h).

RESULTS

Serum LH, T and PRL concentrations showed characteristic diurnal variations across the 15-h period without any differences between the 4- and 8-h sleep conditions. However, total sleep deprivation and 4·5 h of sleep restricted to the first night-half markedly decreased morning T and PRL concentrations (both P ≤ 0·05).

CONCLUSION

Collectively, our data suggest that the effect of sleep restriction on pituitary-gonadal secretory activity may be modulated by sleep timing. While sleep loss in the early part of the night does not affect T and PRL, early awakening and wakefulness during the second part of the night reduces morning circulating T and PRL concentrations.

Sympathetic neural responses to 24-hour sleep deprivation in humans: sex differences

Sleep deprivation has been linked to hypertension, and recent evidence suggests that associations between short sleep duration and hypertension are stronger in women. In the present study we hypothesized that 24 h of total sleep deprivation (TSD) would elicit an augmented pressor and sympathetic neural response in women compared with men. Resting heart rate (HR), blood pressure (BP), and muscle sympathetic nerve activity (MSNA) were measured in 30 healthy subjects (age, 22 ± 1; 15 men and 15 women). Relations between spontaneous fluctuations of diastolic arterial pressure and MSNA were used to assess sympathetic baroreflex function. Subjects were studied twice, once after normal sleep and once after TSD (randomized, crossover design). TSD elicited similar increases in systolic, diastolic, and mean BP in men and women (time, P < 0.05; time × sex, P > 0.05). TSD reduced MSNA in men (25 ± 2 to 16 ± 3 bursts/100 heart beats; P = 0.02), but not women. TSD did not alter spontaneous sympathetic or cardiovagal baroreflex sensitivities in either sex. However, TSD shifted the spontaneous sympathetic baroreflex operating point downward and rightward in men only. TSD reduced testosterone in men, and these changes were correlated to changes in resting MSNA (r = 0.59; P = 0.04). Resting HR, respiratory rate, and estradiol were not altered by TSD in either sex. In conclusion, TSD-induced hypertension occurs in both sexes, but only men demonstrate altered resting MSNA. The sex differences in MSNA are associated with sex differences in sympathetic baroreflex function (i.e., operating point) and testosterone. These findings may help explain why associations between sleep deprivation and hypertension appear to be sex dependent.

Changes in hypothalamic-pituitary-thyroid axis following successful treatment with low-frequency right prefrontal transcranial magnetic stimulation in treatment-resistant depression

Hypothalamic-pituitary-thyroid (HPT) axis abnormalities have been reported in some patients with major depression. To knowledge, however, the effects of low-frequency right prefrontal transcranial magnetic stimulation (TMS) on the HPT axis have not yet been elucidated. The goal of this study was to evaluate alterations in the HPT axis associated with the therapeutic efficacy of TMS treatments. Twenty patients with treatment-resistant depression received five 60-s 1-Hz trains over the right dorsolateral prefrontal cortex. Twelve treatment sessions were administered within a 3-week period (total pulses, 3600). Responders were defined as a > or =50% decrease in the Hamilton Depression Rating Scale (HDRS) score. Serum levels of thyroid-stimulating hormone (TSH), free triiodothyronine (fT3), and free thyroxine (fT4) were measured, respectively, at pre- and post-treatment. There were no significant changes in fT3 and fT4 levels measured at either pre- or post-treatment in either responders or nonresponders; however, TSH levels of responders elevated significantly after TMS treatments. In addition, there was a significant negative correlation between TSH levels at pretreatment and decrease (%) in the HDRS score. These findings suggest that the HPT axis is associated with antidepressant effects of low-frequency right prefrontal TMS, and indicate that lower TSH levels at pre-treatment are correlated with better therapeutic efficacy.

Testosterone and depression: systematic review and meta-analysis

BACKGROUND

Studies suggest that testosterone (TT) replacement may have an antidepressant effect in depressed patients.

OBJECTIVE

The objective of this study was to explore the effect of TT administration on depression using both a systematic review of the literature and a meta-analysis.

METHODOLOGY

A search was conducted of MEDLINE, the Clinical Trials Registry, and Cochrane Central for English-language publications concerning randomized, placebo-controlled trials involving use of TT therapy in depressed patients. We searched for additional trials in the individual reference lists of the articles identified in the search. A study was judged to be relevant for inclusion in this review and meta-analysis if it reported original data from a controlled trial comparing use of TT and placebo in patients diagnosed with a depressive disorder according to DSM criteria, and the treatment response was evaluated according to changes on the Hamilton Rating Scale for Depression (HAM-D). We extracted the following data from the identified studies: study source, total number of participants in the study and in each treatment group, participants' ages, number of participants with a diagnosis of hypogonadism or HIV/AIDS, study duration, type of intervention, and change in HAM-D scores in the groups receiving TT versus placebo. The meta-analysis evaluated the effect of TT replacement on response in depressed patients as measured by change in HAM-D scores in the available placebo-controlled, randomized clinical trails.

RESULTS

Seven studies (N=364) were identified that included a placebo-control group in a double-blind design. Eligibility criteria were clearly reported in all trials. Meta-analysis of the data from these seven studies showed a significant positive effect of TT therapy on HAM-D response in depressed patients when compared with placebo (z=4.04, P<0.0001). Subgroup analysis also showed a significant response in the subpopulations with hypogonadism (z=3.84, P=0.0001) and HIV/AIDS (z=3.33, P=0.0009) as well as in patients treated with TT gel (z=2.32, P=0.02).

CONCLUSIONS

TT may have an antidepressant effect in depressed patients, especially those with hypogonadism or HIV/AIDS and elderly subpopulations. The route by which TT is administered may play a role in treatment response.

Mid-term effects of serial sleep deprivation therapy implemented in cognitive-behavioral treatment on the neuroendocrine response to clomipramine in patients with major depression

While data dealing with neurobiological effects of sleep deprivation (SD) are mainly restricted to the acute effects of a single night, only few studies have investigated mid-term effects after repeated SD. We therefore examined the clinical and hormonal characteristics of depressive patients before and after serial SD to determine potential sustained effects, focusing especially on serotoninergic functions. One tool to investigate serotoninergic dysfunction in depression is the use of serotoninergic agents to stimulate hormonal secretion, which is assumed to normalize during a clinically effective therapy. Eighteen drug-free inpatients with unipolar major depression received cognitive-behavioral treatment for three weeks and - according to a randomized control design - additional SD therapy (six nights of total SD within three weeks, separated by nights of recovery sleep) or no SD therapy (control group). Serotoninergic function was assessed by measuring cortisol and prolactin in response to intravenously administered clomipramine (12.5mg) before and after the treatment period. The post-treatment challenge test was performed three days after the last SD night. Apart from of a transient overnight improvement of mood induced by SD, both groups showed a comparable clinical course during the three-week treatment period. Compared to the control group, the SD-treated patients exhibited significantly decreased pre-stimulation cortisol levels and significantly increased cortisol responses to clomipramine, whereas no treatment effects were observed for prolactin. In conclusion, our findings suggest that the mid-term effects of serial SD therapy lead to a normalization of serotoninergic dysfunction, although an obvious impact on clinical symptoms was not detected.

Icariin from Epimedium brevicornum attenuates chronic mild stress-induced behavioral and neuroendocrinological alterations in male Wistar rats

Chronic mild stress (CMS) is suggested to produce abnormalities in the hypothalamic-pituitary-adrenal (HPA) axis and hypothalamus-pituitary-thyroid (HPT) axis. Therefore, compound that attenuates the neuroendocrinological alterations may have potential as antidepressant. The behavioral and neuroendocrinological effects of icariin, a major constituent of flavonoids isolated from Epimedium brevicornum, were investigated in the CMS model of depression in male Wistar rats. CMS procedure caused an anhedonic state in rats resulted in increased corticotropin-releasing factor (CRF) concentrations in dissected brain regions and serum, decreased total triiodothyronine (tT3) in serum with no significant changes in serum adrenocorticotrophic hormone (ACTH) and thyroxine (tT4). Administration of icariin reversed CMS-induced sucrose intake reduction and CRF elevation. These results suggested that icariin possessed potent antidepressant-like activities which were at least in part mediated by improving the abnormalities in the HPA axis functions. However, we did not find a clear correlation between the HPT axis and icariin treatment in the CMS-treated rats.

Endocrinological and catecholaminergic alterations during sleep deprivation and recovery in male rats

Since previous data of our group showed increased concentrations in HPA axis hormones in sleep deprived rats, we hypothesized that this augmentation could produce effects in other hormonal systems, particularly in the sexual system. Considering that little is known about how the hormonal system changes during the recovery period after sleep deprivation (SD), our objective was to examine from what point SD alters sexual and stress-related hormones along with plasma catecholamine concentrations during 4 days. We also sought to verify the time course of their recovery after an equivalent period of recovery sleep. Rats were deprived of sleep by the platform technique for 1-4 days and were allowed to recover for the same period. Plasma catecholamines [dopamine (DA) and noradrenaline (NOR)], testosterone, estrone, progesterone, prolactin, corticosterone and adrenocorticotropic hormone (ACTH) concentrations were measured. Comparisons between groups showed that the SD procedure used in the present study produced marked alterations in almost all studied hormones from 24 h of SD, except for estrone and prolactin (which required 96 h of SD to become altered). Testosterone and estrone decreased, whereas progesterone, prolactin, corticosterone, ACTH, DA and NOR increased. During recovery period, progesterone, prolactin and corticosterone concentrations returned to control levels, whereas testosterone, estrone, NOR and DA did not. In addition, after 48 h of recovery ACTH and NOR decreased below control concentrations, remaining low until 96 h of sleep recovery. Thus, SD showed long lasting, differential effects upon these neurochemicals suggesting that each has its own pattern of responses to SD as well as variable periods of recovery.

Does paradoxical sleep deprivation and cocaine induce penile erection and ejaculation in old rats?

A recent study has established that paradoxical sleep deprivation (PSD) and cocaine administration elicit genital reflexes (penile erection and ejaculation) in young rats. To discover whether the same effects occurred in old animals submitted to PSD, we administered cocaine (15 mg/kg) to young (3-month) and old (22-month) male rats after a 4-day period of PSD or at the equivalent time-point in control animals. We then evaluated erections and ejaculations. Sixty per cent of the old-PSD group displayed erection, although ejaculation was not observed. Genital reflexes were absent in young and old control groups. We found that PSD reduced testosterone and increased progesterone levels in both young and old PSD groups. In conclusion, our results suggest that although genital reflexes usually decrease with age, testosterone levels alone cannot account for these changes. The interaction of PSD and cocaine probably enhances dopamine transmission in the brain and may elicit penile erection in old rats.

Effects of supraphysiological thyroxine administration in healthy controls and patients with depressive disorders

BACKGROUND

Thyroxine (T(4)) in supraphysiological doses has been found to be an effective supplemental treatment in open studies for refractory mood disorders. Unexpectedly, only minimal side effects have been reported. The goal of the present study was to investigate whether healthy controls and depressed patients differ in their ability to tolerate supraphysiological doses of T(4).

METHODS

This was an 8-week open study to investigate side effects and levels of thyroid hormones in 13 healthy controls and to compare results with those of 13 patients with refractory depression (unipolar and bipolar) undergoing the similar procedures and T(4) dosing regimen in a previous augmentation study.

RESULTS

The rate of discontinuation due to side effects was significantly higher in the control group than for the patients (38% versus 0%). The severity of the side effects in the controls increased significantly during treatment with T(4). The side effect scores of the patients were higher than those of the controls prior to T(4) treatment, but did not change significantly during the treatment period. Although the serum concentrations of thyroid hormones rose significantly in both groups, concentrations of fT(3) and fT(4) were significantly higher in the controls.

CONCLUSIONS

Healthy controls and depressed patients respond significantly differently to supraphysiological T(4). Healthy controls experience higher elevations of thyroid hormones in response to supraphysiological T(4), thus inducing significantly more side effects and discontinuation.

LIMITATIONS

Open-label study; groups were studied at different times; in contrast to healthy controls, depressed patients were also taking antidepressants.

CLINICAL RELEVANCE

Studies provide safety and tolerability data on treatment with supraphysiological doses of T(4).

The hypothalamic-pituitary-gonadal axis in mood disorders

This article has demonstrated that stress and HPA axis activation affect the reproductive axis. Despite similarities in the HPA axis picture between women with major depression and those with hypothalamic amenorrhea and exercise or nutritional amenorrhea, no abnormalities in LH secretion have been documented in major depression. Lower estradiol in the follicular phase in depressed women and lower testosterone in depressed men however, have been observed [81, 92]. Although PMS would appear to be the best candidate for a mood disorder associated with abnormalities in reproductive hormones, no abnormalities in LH, estradiol or progesterone have been documented in PMS either [62]. Similarly, blockade of progesterone appears to be ineffective as a treatment for PMS [79]. Complete elimination of monthly cycling with leuprolide improves mood, however. No published studies have examined women with major depression to determine whether leuprolide will exacerbate or improve depressive symptoms. Some studies suggest beneficial effects of estrogen on mood in postmenopausal women, but no placebo controlled studies have explored estrogen augmentation in the treatment of major depression in either post- or premenopausal women, although estrogen is beneficial in women with perimenopause-related mood disorders [78].

Potential mechanisms of the sleep therapies for depression

Sleep deprivation for one night has been investigated as a treatment for depression since the first publications describing its antidepressant properties almost 30 years ago [Pflug and Tolle, 1971: Int Pharmacopsychiatry 6:187-196]. It remains a field of active research. It is the only intervention consistently demonstrated to produce next-day antidepressant results. This makes sleep deprivation an exciting and unique tool to study the pathophysiology of depressive disorders and to formulate targets for novel antidepressant agents. Importantly, it is also an effective, but underused, clinical treatment for unipolar and bipolar depression.

Suprathreshold repetitive transcranial magnetic stimulation elevates thyroid-stimulating hormone in healthy male subjects

Repetitive transcranial magnetic stimulation (rTMS) has been introduced as a new antidepressive treatment strategy. The mode of action by which the antidepressive effect is brought about is not yet clear. Other antidepressive treatment strategies such as sleep deprivation are associated with an increase of plasma thyroid-stimulating hormone (TSH) levels that correlate with clinical improvement. In the present study, the effect of left prefrontal suprathreshold (120% of motor threshold) rTMS on TSH plasma levels of 19 healthy male subjects was investigated in comparison with subthreshold (80% of motor threshold) and sham stimulation. Suprathreshold rTMS was followed by a significant relative increase of TSH levels 10 and 60 minutes after stimulation in comparison with subthreshold and sham stimulation. The more pronounced effect of suprathreshold rTMS on TSH plasma levels might be important for the determination of optimal stimulation parameters in the treatment of depressed patients.

Cortisol circadian rhythms during the menstrual cycle and with sleep deprivation in premenstrual dysphoric disorder and normal control subjects

BACKGROUND

In this study we extended previous work by examining whether disturbances in the circadian rhythms of cortisol during the menstrual cycle distinguish patients with premenstrual dysphoric disorder (PMDD) from normal control (NC) subjects. In addition, we tested the differential response to the effects of early and late partial sleep deprivation on cortisol rhythms.

METHODS

In 15 PMDD and 15 NC subjects we measured cortisol levels every 30 min from 6:00 PM to 9:00 AM during midfollicular (MF) and late luteal (LL) menstrual cycle phases and also during a randomized crossover trial of early (sleep 3:00 AM-7:00 AM) versus late (sleep 9:00 PM-1:00 AM) partial sleep deprivation administered in two subsequent and separate luteal phases.

RESULTS

In follicular versus luteal menstrual cycle phases we observed altered timing but not quantitative measures of cortisol secretion in PMDD subjects, compared with NC subjects: in the LL versus MF phase the cortisol acrophase was a mean of 1 hour earlier in NC subjects, but not in PMDD subjects. The effect of sleep deprivation on cortisol timing measures also differed for PMDD versus NC subjects: during late partial sleep deprivation (when subjects' sleep was earlier), the cortisol acrophase was almost 2 hours earlier in PMDD subjects.

CONCLUSIONS

Timing rather than quantitative measures of cortisol secretion differentiated PMDD subjects from NC subjects both during the menstrual cycle and in response to early versus late sleep deprivation interventions.

Thyroid function and response to 48-hour sleep deprivation in treatment-resistant depressed patients

BACKGROUND

Clinical depression is associated with abnormalities of the hypothalamic-pituitary-thyroid axis. Changes in thyroid function during sleep deprivation may be related to its antidepressant effects.

METHODS

Levels of thyroid-stimulating hormone, tri-iodothyronine, tri-iodothyronine uptake, thyroxine, and free thyroxine were measured before, during, and after a 48-hour sleep deprivation in nine treatment-resistant depressed patients. Clinical state was assessed every 4 hours. A retrospective study of 26 similar patients was added for cross-validation.

RESULTS

Significant increases in thyroid-stimulating hormone and tri-iodothyronine during sleep deprivation were not correlated with clinical improvement. Sleep deprivation responders had lower tri-iodothyronine uptake levels than nonresponders in both the prospective (p <.02) and the retrospective (p <.03) samples.

CONCLUSIONS

The lower tri-iodothyronine uptake values in responders may identify a subgroup of depressed patients who respond to sleep deprivation by virtue of some abnormality of the hypothalamic-pituitary-thyroid axis that is temporarily corrected by sleep deprivation.

Sleep deprivation in depression: what do we know, where do we go?

Manipulations of the sleep-wake cycle, whether of duration (total or partial sleep deprivation [SD]) or timing (partial SD, phase advance), have profound and rapid effects on depressed mood in 60% of all diagnostic subgroups of affective disorders. Relapse after recovery sleep is less when patients are receiving medication; it may be prevented by co-administration of lithium, pindolol, serotonergic antidepressants, bright light, or a subsequent phase advance procedure. Diurnal and day-to-day mood variability predict both short-term response to SD and long-term response to antidepressant drug treatment. These mood patterns can be understood in terms of a "two-process model of mood regulation" based on the model well established for sleep regulation: the interaction of circadian and homeostatic processes. The therapeutic effect of SD is postulated to be linked to changes in disturbed circadian- and sleep-wake-dependent phase relationships and concomitant increase of slow-wave-sleep pressure; additionally, SD-induced sleepiness may counteract the hyperarousal state in depression. This model has the advantage of providing a comprehensive theoretical framework and stringent protocols ("constant routine," "forced desynchrony") to dissect out specific disturbances. Many aspects tie in with current serotonergic receptor hypotheses of SD action. A treatment inducing euthymia in severely depressed patients within hours is an important therapeutic option that has come of age for clinical use.

Sleep deprivation effects on the activity of the hypothalamic-pituitary-adrenal and growth axes: potential clinical implications

OBJECTIVES

Although several studies have shown that sleep deprivation is associated with increased slow wave sleep during the recovery night, the effects of sleep deprivation on cortisol and growth hormone (GH) secretion the next day and recovery night have not been assessed systematically. We hypothesized that increased slow wave sleep postsleep deprivation is associated with decreased cortisol levels and that the enhanced GH secretion is driven by the decreased activity of the HPA axis.

DESIGN AND SUBJECTS

After four consecutive nights in the Sleep Laboratory, 10 healthy young men were totally deprived of sleep during the fifth night, and then allowed to sleep again on nights six and seven. Twenty-four hour blood sampling was performed serially every 30 minutes on the fourth day, immediately following the previous night of sleep and on the sixth day, immediately after sleep deprivation.

MEASUREMENT

Eight-hour sleep laboratory recording, including electroencephologram, electro-oculogram and electromyogram. Plasma cortisol and GH levels using specific immunoassay techniques.

RESULTS

Mean plasma and time-integrated (AUC) cortisol levels were lower during the postdeprivation nighttime period than on the fourth night (P < 0.05). Pulsatile analysis showed significant reduction of both the 24 h and daytime peak area (P < 0.05) and of the pulse amplitude (P < 0.01), but not of the pulse frequency. Also, the amount of time-integrated GH was significantly higher for the first 4 h of the postdeprivation night compared to the predeprivation night (P < 0.05). Cross-correlation analyses between the absolute values of the time-series of each hormone value and percentage of each sleep stage per half hour revealed that slow wave sleep was negatively correlated with cortisol and positively correlated with GH with slow wave sleep preceding the secretion of these hormones. In contrast, indices of sleep disturbance, i.e. wake and stage 1 sleep, were positively correlated with cortisol and negatively correlated with GH.

CONCLUSION

We conclude that sleep deprivation results in a significant reduction of cortisol secretion the next day and this reduction appears to be, to a large extent, driven by the increase of slow wave sleep during the recovery night. We propose that reduction of CRH and cortisol secretion may be the mechanism through which sleep deprivation relieves depression temporarily. Furthermore, deep sleep has an inhibitory effect on the HPA axis while it enhances the activity of the GH axis. In contrast, sleep disturbance has a stimulatory effect on the HPA axis and a suppressive effect on the GH axis. These results are consistent with the observed hypocortisolism in idiopathic hypersomnia and HPA axis relative activation in chronic insomnia. Finally, our findings support previous hypotheses about the restitution and immunoenhancement role of slow wave (deep) sleep.

Sleep deprivation therapy in depressive illness and Parkinson's disease

1. Sleep deprivation is commonly associated with feelings of fatigue and cognitive impairment. 2. Patients with depressive illness, however, often experience mood improvements under these same conditions. 3. Other studies now show that tremor and rigidity, in patients with Parkinson's disease, are also improved by sleep depression therapy. 4. The neural substrates which underlie these effects are unclear. Some recent evidence, however, suggests that sleep deprivation may activate mechanisms which are otherwise typical of conditions of metabolic stress. 5. A common feature of these mechanisms is the suppression of cholinergic activity which is thought to be excessive, in relation to monoamine transmission, in both depression and Parkinson's disease.

Reversal of diurnal cortisol rhythm and suppression of plasma testosterone in obstetric residents on call

OBJECTIVE

The study was undertaken to quantify the psychologic and physiologic responses to the stresses of an obstetrics/gynecology residency program.

METHODS

Six male residents were studied on four occasions: one day during the first 2 weeks of their residency, one day immediately following a vacation period, one day after a night on call in obstetrics, and one day while in the gynecology clinic. Stress was evaluated by validated psychologic instruments and by levels of plasma testosterone, luteinizing hormone (LH), cortisol, and prolactin in morning and afternoon blood samples.

RESULTS

Self-reported stress was significantly elevated during the first 2 weeks of the residency after a night on call. Anxiety scores were significantly elevated after a night on call as were depression subscores for some residents. Plasma testosterone was highly significantly suppressed after the obstetrics night on call and during the first 2 weeks of the residency in comparison with the vacation period. Luteinizing hormone levels were also significantly lower after the obstetrics on-call experience. Plasma cortisol levels after a night on call were suppressed in the morning and normal or elevated in the afternoon. In comparison, the gynecology rotation was associated with normal levels of testosterone and lower levels of cortisol.

CONCLUSION

In this small sample of residents, we observed an inverse relationship between self-reported stress levels and the concentrations of plasma testosterone and LH. The high levels of stress and anxiety expressed after a night on call also disrupted the normal pattern of plasma cortisol levels.

Psychoneuroendocrinology of depression. Hypothalamic-pituitary-gonadal axis

Women are more susceptible than men to depression, particularly during periods of rapid fluctuation of gonadal hormones, such as premenstrually, postpartum, and during the climacteric. This review summarizes the evidence for the association of depression with abnormalities in reproductive hormones. Although there are similarities in stress hormones changes between depressed women and women with stress-related amenorrhea, no abnormalities in LH activity have been documented in depression. Similarly no abnormalities in LH, estradiol, or progesterone have been documented in premenstrual syndrome (PMS), although complete elimination of monthly cycling with leuprolide improves mood. Some studies have suggested beneficial effects of estrogen on mood in postmenopausal women but as yet there have been no adequately controlled studies of estrogen treatment of either premenopausal or postmenopausal women.

Relationships between thyroid hormone and antidepressant responses to total sleep deprivation in mood disorder patients

BACKGROUND

Acute transient antidepressant effects of sleep deprivation are consistently observed in 50% of depressed patients, but the mechanisms of these, at times, dramatic improvements in mood have not been adequately elucidated. Some, but not all, studies suggest a relationship to increased thyroid-stimulating hormone (TSH) secretion.

METHODS

TSH and other thyroid indices were measured at 8:00 AM after a baseline night's sleep and at 8:00 AM following a night of total sleep deprivation (S.D.) in 34 medication-free, affective disorder patients assessed with Hamilton, Beck, and Bunney-Hamburg depression ratings as well as two hourly self-ratings on a visual analog scale.

RESULTS

Compared with baseline, S.D. induced highly significant increases in TSH, levothyroxine, free levothyroxine, and triiodothyronine. The 12 S.D. responders tended to have greater TSH increases than the 15 nonresponders (p < .10). The change in Beck depression ratings significantly correlated with the change in TSH (r = -.40, p = .0496, n = 24).

CONCLUSIONS

These data are consistent with several other reports of a significant relationship between degree of antidepressant response to S.D. and increases in TSH measured at 8:00 AM near their usual nadir. Acute removal of the sleep-related break on the hypothalamic-pituitary-thyroid axis remains a promising candidate for the mechanism of sleep deprivation-induced improvement in mood in depressed patients.

Serum concentrations of thyroid hormones in patients with nonseasonal affective disorders during treatment with bright and dim light

Serum concentrations of thyroxine (T4), triiodothyronine (T3), and thyrotropine were measured in 34 patients with nonseasonal affective disorders before and after 1 week of light treatment. Nineteen of these patients received bright white light (2500 lx) and 15 dim red light (50 lx) for 2 hours daily in the mornings over a 1-week period. Slight but significant reductions in the rating scores for the depressive symptomatology were found for both the bright-and dim-light groups, but there were no significant differences between the two groups. The improvement is thus most likely a placebo effect. Surprisingly, the small changes in the severity of the depressive symptoms in the group as a whole were significantly correlated to the changes in the serum levels of T4 during the weeks of bright- and dim-light treatment, respectively. The more a patient improved, the further his or her T4 level fell and vice versa. The fluctuations in the concentrations of T4 during light treatment were significantly greater in the depressed patients than in a group of 12 healthy controls who also received bright or dim light, whereas the changes in T3 were significantly smaller than those of the healthy controls. The pronounced fluctuations in T4 levels were probably not secondary to changes in mood. Rather, they are likely to reflect changes in tissue (intracellular) metabolism of T4, which may be involved in the mechanisms underlying the fluctuations in mood in these patients.

The management of treatment-resistant depression in the medically ill

There are a few well-designed studies to systematically assess treatment-resistant depression in the medically ill patient. Psychiatrists, however, do have extensive clinical experience in treating depression in the medical patient. This experience can be useful in helping to determine treatment resistance and in selecting consequent treatment choices. A decision tree is offered in Table 1 to clarify the questions the clinician must answer. The first step is to evaluate the role of the medical illness and to decide whether or not treating that effectively will also clear the depression. Physicians may find it helpful to use a decision tree in initiating treatment of patients with depression and physical illness. Once it has been clarified that the diagnosis of depression is a correct one and that an antidepressant medication is in order, consideration of safety, side effects, and other current prescriptions used by the patient must occur. Drug-drug interactions as well as changes in the clearance of medications are critical to the effectiveness of the choice and tolerability for the patient. An antidepressant agent needs to be given for an adequate time with optimization of dosing. Augmenting a medication to increase its therapeutic action could be tried if one agent alone is not effective. An alternative approach is that the second drug selected might affect different neurotransmitters, and the combination of mechanisms would result in resolution of symptoms. Adding psychotherapy, especially when social supports are lacking, can be particularly helpful. ECT is an important consideration for severe depression when suicidal concerns are imminent or the patient has not responded to pharmacotherapy trials. While we await further studies of treatment-resistant depression in large enough numbers of patients with particular illnesses, we can use these guidelines to direct our decisions to switch or augment our initial choices to provide the safest, most effective care possible.

Serum prolactin, growth hormone, total corticoids, thyroid hormones and thyrotropine during serial therapeutic sleep deprivation

In 13 patients fulfilling DSM-III-R criteria for a major depressive episode, hormone serum levels were measured at 8 AM on the day before and on the first and second days after partial sleep deprivation (PSD) late in the night during a 4-week course of therapy with amitriptyline in combination with 6 PSDs. Prolactin, human growth hormone (HGH) and total corticoids were not influenced by PSD. In contrast, T3 and thyrotropine (TSH) were elevated significantly on the 1st day after PSD throughout the series, but T4 less regularly. Although TSH reverted regularly to baseline values on the 2nd day after PSD, i.e. after a full night's sleep, T3 remained elevated. The hormones under discussion do not predict the therapeutic PSD effect. Nor can any correlation be determined between endocrine and clinical changes on the 1st or 2nd day after PSD. In connection with findings from sleep deprivation research in animals and in healthy subjects, the results suggest that thyroid changes under PSD may be nonspecific and unrelated to antidepressive PSD effects.

Hypothalamic-pituitary-gonadal axis, prolactin, and cortisol in alcoholics during withdrawal and after three weeks of abstinence: comparison with healthy control subjects

Serum concentrations of luteinizing hormone, follicle-stimulating hormone, testosterone, androstenedione, estradiol, sex hormone-binding globulin, cortisol, and prolactin were measured in 12 male chronic alcoholics once during withdrawal and once after 21 days of abstinence. The results were compared with those of 14 healthy volunteers. During withdrawal, luteinizing hormone, estradiol, and cortisol levels were significantly enhanced. Estradiol and cortisol concentrations fell significantly during abstinence, whereas luteinizing hormone concentrations remained elevated. The results may be interpreted as follows: the well-known inhibitory effect of alcohol on the biosynthesis of testosterone may have led to a compensatory increase in luteinizing hormone secretion, so that normal serum concentrations of testosterone were maintained. On the other hand, peripheral conversion from androstenedione to estradiol via aromatase pathways seemed to be enhanced in chronic alcoholics, at least during withdrawal. Whether this marked increase in estradiol concentrations is implicated in different clinical and psychological symptoms seen in chronic alcoholics remains to be investigated.

Effects of sleep deprivation on serotonin function in depression

There is considerable evidence that antidepressant treatments enhance serotonin (5-HT) function. In order to evaluate whether sleep deprivation (SD) produces alterations in 5-HT function, the increase in prolactin (PRL) produced by intravenous tryptophan (TRP) was assessed in depressed patients following SD and undisturbed sleep (US). Eleven depressed patients received mood ratings and TRP infusions after either SD or US, 1 week apart. In five women, but not six men, the TRP-induced PRL rise was markedly enhanced after SD compared to US. Mood score changes were not significantly different between US and SD and there was no significant relationship of mood changes to the TRP induced PRL response. The data suggests that SD produces an increase in 5HT function in female depressed patients. The lack of identified SD-induced changes in 5-HT function in men may be due to lower sensitivity of the TRP-induced PRL rise in depressed men than women.

Hypothalamic-pituitary-thyroid (HPT) axis in chronic alcoholism. I. HPT axis in chronic alcoholics during withdrawal and after 3 weeks of abstinence

Thyroxine (T4), free T4 (fT4), triiodothyronine (T3), free T3 (fT3), reverse T3 (rT3), thyrotropin (TSH), thyroxine binding globulin (TBG), and T3 uptake were measured in 14 chronic alcoholics during withdrawal and after 21 days of abstinence. Results were compared with those of 16 healthy volunteers. During withdrawal, the fT4 and fT3 concentrations were subnormal, whereas the respective protein-bound fractions were normal. T4, T3, and TBG increased during the abstinence period, T3 and TBG being significantly higher than in normals at the second measuring time. T3 uptake values fell, but remained well within the normal range at both measuring times. During abstinence, the fT3 levels remained significantly lower than in healthy subjects. rT3 concentrations decreased, but not significantly. The TSH values were normal throughout. These results showed numerous abnormalities in the hypothalamic-pituitary-thyroid axis in alcoholics, the reasons for which are as yet unclear. The following possible interpretations are suggested: 1. The abnormally low serum fT3 and fT4 levels during withdrawal might reflect an increase in tissue uptake. 2. The increases in T4--and partly those in T3--during abstinence seem to reflect increased binding by TBG, the level of which rose markedly for reasons as yet unknown. 3. If increases in TBG during abstinence are taken into account, the decreases in rT3 concentrations may reach the level of statistical significance. These falls in rT3 concentrations may reflect an increase in rT3 metabolization (deiodination) in various tissues, including the CNS, leading to a reduction in serum rT3 bioavailability. 4. Factors such as liver disease, protein caloric malnutrition, and "psychological stress" do not fully explain all these abnormalities. A direct effect of ethanol on intracellular thyroid hormone metabolism and/or function seems conceivable.

Psychological and endocrine abnormalities in refugees from East Germany: Part II. Serum levels of cortisol, prolactin, luteinizing hormone, follicle stimulating hormone, and testosterone

We investigated afternoon serum levels of cortisol, prolactin, luteinizing hormone (LH), follicle stimulating hormone (FSH), and testosterone in a group of 84 refugees who had fled from East to West Germany and suffered from psychiatric disorders within 6 weeks of their arrival in West Berlin. The mean hormone levels were compared with those of healthy control subjects. Cortisol levels were lower and LH levels were higher in the patients than in the control subjects, but only at trend levels of significance. No differences were found between the prolactin, FSH, or testosterone concentrations of the two groups. The patients with major depressive disorder (MDD) had a significantly higher mean cortisol level than the mean levels in the subgroups in whom posttraumatic stress disorder, dysthymia, and adjustment disorder were diagnosed. It can be concluded that the hypothalamic-pituitary-adrenal axis may "adapt" during severe long-term psychological stress and that long-term stress may be only one of the neurochemical mechanisms underlying the hypercortisolemia in patients with MDD.

Psychological and endocrine abnormalities in refugees from East Germany: Part I. Prolonged stress, psychopathology, and hypothalamic-pituitary-thyroid axis activity

The influence of prolonged psychological stress on hormonal secretion was investigated in 84 East Germany refugees suffering from psychiatric disorders within 6 weeks of their arrival in West Berlin shortly before or after the fall of the Berlin Wall. Before leaving the German Democratic Republic, these patients had already experienced prolonged stress, which continued after migration. In most cases, the diagnosis was anxious-depressive syndrome with vegetative complaints and symptoms of increased arousal. Their formal DSM-III-R diagnoses (American Psychiatric Association, 1987) included adjustment disorders, depressive disorders, and anxiety disorders (the latter including posttraumatic stress disorder). Serum levels of thyroid stimulating hormone (TSH) and thyroid hormones (thyroxine, free thyroxine, triiodothyronine, and reverse triiodothyronine) were measured and compared with those of 20 healthy control subjects. TSH and all thyroid hormone concentrations were significantly reduced in the patient group. Fifty-two of the patients (62%) were in the hypothyroid range but did not show any clinical signs of hypothyroidism. These disturbances in hormonal secretion were not correlated to any psychiatric diagnosis or to the severity of acute or chronic stress. The marked abnormalities in the hypothalamic-pituitary-thyroid axis seen in these refugees differ from those reported in depression and would seem to reflect severe chronic stress rather than specific psychiatric disorders. The underlying neurochemical mechanisms remain to be investigated.

The influence of sleep deprivation on thyroid hormone metabolism in rat frontal cortex

The effects of 24 h sleep deprivation (SD) on central thyroid hormone metabolism were investigated in rat frontal cortex. SD induced a significant rise in the activity of iodothyronine type II 5'-deiodinase (5'D-II), which catalyzes the conversion of thyroxine (T4) to triiodothyronine (T3) in the rat central nervous system (CNS). Tissue concentrations of T4 remained unchanged, whereas levels of T3 increased to more than 150% of the corresponding levels measured in control rats. Serum concentrations of T4 and T3 were also significantly enhanced by SD--an effect that has previously been described in depressed patients having undergone the same procedure. These results suggest that SD can dramatically increase T3 concentrations (and possibly function) in rat CNS. Whether or not these findings are of relevance in regard to the well-known antidepressant effect of SD in psychiatric patients with major depressive disorders remains to be established.

Influence of partial sleep deprivation on the secretion of thyrotropin, thyroid hormones, growth hormone, prolactin, luteinizing hormone, follicle stimulating hormone, and estradiol in healthy young women

The influence of partial sleep deprivation during the second half of the night on the secretion of thyroid stimulating hormone (TSH), thyroxin (T4), free T4 (fT4), triiodothyronine (T3), prolactin (PRL), growth hormone (GH), luteinizing hormone (LH), follicle stimulating hormone (FSH), and estradiol (E2) was investigated in 10 healthy young women. Blood samples were drawn at hourly intervals over a 64-hour period (i.e., 3 consecutive days and nights). During night 2, all subjects were awakened at 1:30 a.m. During partial sleep deprivation, TSH concentrations increased significantly and remained elevated throughout the following day. Levels of T4, fT4, and T3 were enhanced during the partial sleep deprivation hours only, and changes in these hormones seemed to be independent of TSH. PRL levels decreased, LH and E2 concentrations increased, and GH and FSH secretion remained unchanged during partial sleep deprivation. This pattern of change of different endocrine axes during partial sleep deprivation resembles those seen after total sleep deprivation, suggesting that similar neurochemical changes are induced by both forms of antidepressant therapy. The late evening GH peak occurred almost exclusively before the onset of sleep. Partial sleep deprivation did not influence the chronobiological profiles of any of the hormones investigated. The chemical changes underlying these alterations are speculated to involve enhancement of central norepinephrine and dopamine activity with a concomitant increase in the activity of the sympathetic nervous system.

Endocrinology and the psychiatrist

Objective:Exegetic review of the three areas of common interest to the endocrinologist and the psychiatrist.Method:Literature review through Science Citation Index and references in BMJ, Lancet, Nature, and Science.Findings:Psychiatric symptoms, specific in each condition, may develop in the course of a classical endocrinopathy. Though introduced as a possible diagnostic aid, titration of the hypothalamico-pituitary control of the adrenal and thyroid glands has proved to be a useful research strategy and possible prognostic indicator in affective disorders. Growth in our knowledge of the behaviour effects, distribution, function and pathophysiology of neuropeptides during the last two decades opens a magic casement on their potential value in neuropsychiatric theory and therapy.Conclusion:The psychiatrist ignores endocrinology at his peril, as does the endocrinologist psychiatry, especially in regard to the emerging role of peptides in neuromodulation.

A clinical trial of sleep deprivation in combination with antidepressant medication

The literature suggests that sleep deprivation can potentiate the effect of antidepressant medication in depressed patients. However, the clinical efficacy of sleep deprivation has not been demonstrated definitively, in part because it is difficult to design an adequate control condition. We conducted a trial of sleep deprivation in 26 depressed patients who remained symptomatic despite 3 months of treatment with antidepressant medication. Since the literature indicates that early sleep deprivation (ESD), carried out in the first half of the night, is a less effective antidepressant than late sleep deprivation (LSD), carried out in the second half of the night, we designed a study that attempted to use ESD as a control condition for LSD. Patients were randomly assigned to ESD or LSD, received a total of 4 nights of sleep deprivation over 2 weeks, and were followed in clinic for the 3 subsequent weeks. ESD proved to be as effective an antidepressant as LSD, with the overall sample showing a mild, but statistically significant, response. There was a significant correlation between patients' acute response at the time of the first course of sleep deprivation treatments and their improvement over the course of the study. There were significant changes in plasma levels of thyroid stimulating hormone, free triiodothyronine, prolactin, and cortisol measured at 8 a.m. before and after sleep deprivation, and in the followup period, but there were no significant correlations between changes in hormonal levels and either acute or chronic response to sleep deprivation.

Sleep deprivation therapy

This review reports, with as much detail as possible, on the literature relating to therapeutic sleep deprivation (or induced-wakefulness therapy) since it was first described in 1971. The antidepressive effect of sleep deprivation has been substantiated by numerous studies. A series of clinical predictors of response to sleep deprivation are also described. Partial sleep deprivation late in the night is equivalent to total sleep deprivation in terms of therapeutic value and--because of its simpler application--can be regarded today as the sleep deprivation method of choice. The status of sleep deprivation in the overall treatment schedule for depressive disorders is discussed in detail. Numerous findings, some of them contradictory, have been published on the effect of sleep deprivation on biological variables. To date, no unequivocal explanation has been found for the mechanism of action of sleep deprivation.