Neuroendocrine and clinical characteristics of major depressed patients exhibiting sleep-onset REM

BACKGROUND

Previous reports suggest an association between sleep-onset REM (SOREM) and some clinical characteristics in depressive illness such as age, psychosis, and depression severity. The present study is aimed at further investigating clinical and neuroendocrine correlates of SOREM, controlling for the age-related variability in clinical data.

METHODS

Thyroid-stimulating hormone response to thyrotropin-releasing hormone, postdexamethasone cortisol levels, and clinical characteristics of 25 major depressive (MD) patients exhibiting SOREM in at least one of three consecutive recording nights were compared to those of 25 age- and sex-matched MD patients with three REM latencies above 50 min.

RESULTS

SOREM patients experienced more affective episodes leading to hospitalization and a shorter duration of current episode than patients with three REM latencies above 50 min. No association between psychosis and SOREM could be demonstrated, and hypothalamic-pituitary-adrenal or -thyroid axis disturbances were not more prevalent in SOREM patients.

CONCLUSIONS

Our results suggest that clinical history rather than cross-sectional clinical characteristics relates to the occurrence of SOREM in major depressed patients.

The dexamethasone suppression test and sleep electroencephalogram in nonbipolar major depressed inpatients: a multivariate analysis

BACKGROUND

The present study further examined relationships between postdexamethasone cortisol plasma values and sleep electroencephalogram (EEG) parameters.

METHODS

The dexamethasone suppression test (DST) and polysomnographic recordings were performed in a sample of 300 inpatients with primary major depressive disorder (MDD) (102 men and 198 women, mean age 44 +/- 12 years, range 20-74 years) consecutively admitted to Erasme Hospital (Brussels, Belgium) between 1981 and 1992.

RESULTS

The DST was abnormal in 40% of the sample. Postdexamethasone cortisol plasma values at 4:00 PM were significantly influenced by age, but not by gender. They were also significantly and positively correlated with weight loss, total scores on the Hamilton Depression Rating Scale, total scores on the Newcastle Scale, percentage of awakenings during sleep, and percent of stage 1. They were significantly and negatively correlated with percent of stage 2, slow-wave sleep, and REM sleep. Multiple regression analyses were conducted in two successive steps. First among clinical variables, only age and depressive symptom severity remained correlated with postdexamethasone plasma cortisol values. In the second step, with age and severity held constant, postdexamethasone plasma cortisol values were positively associated with amount of wake time and stage 1, and negatively with amount of slow-wave sleep.

CONCLUSIONS

These findings provide further indirect support for an overarousal state in MDD with sympathoadrenal system hyperactivity and impaired sleep continuity. They also underline the importance of taking into account various clinical confounding factors in the interpretation of both DST and sleep EEG results.

[Sleep during post-partum depression]

BACKGROUND

Numerous studies have been published on postnatal depression (PND) over the last 10 years. A controversy has arisen regarding the specificity of the diagnostic concept. It is based on 2 points: the hormonal environment and the course and recurrence of PND. EEG Sleep studies are also numerous, but this paper presents the first study on EEG sleep profile during PND.

METHODS

24 women suffering from major depression according to RDC were placed in 3 groups: 1) Group A (n = 8): PND; 2) Group B (n = 8): depression with a past history of PND; 3) Group C (n = 8): depression without a past history of PND. Women were age-matched and according to the Hamilton 24 item severity score. Group A patients were delivered within less that 6 months, groups B and C within a minimum of 3 years. None were pregnant or alcoholic, and none were physically ill.

RESULTS

There was no difference between groups B and C. Group A was characterised by a significantly longer stage IV sleep. There was also a strong tendency to a shorter stage I sleep and a better quality of sleep (total sleep time and number of awakenings) during PND.

DISCUSSION

Our study shows that, even if similar to major depression, specific polysomnographic alteration can be found during post-partum depression. This finding is relevant to the hypothesis of PND's diagnostic specificity. The perfect similarity between groups B and C strengthens this evidence. Nevertheless, the significance of SWS alterations are difficult to explain and additional studies are required.

CONCLUSION

The EEG Sleep profile during PND differs from major depression of the same severity. This appears to favour the specificity of the diagnostic concept.

[Sleep disorders and neuroendocrine regulation in depression]

In a series of investigations we explored 24 hour neuroendocrine profiles as well as sleep patterns in a sample of monozygotic and dizygotic normal twins as well as in a group of depressed and schizophrenic patients. Our results indicate that genetic factors influence some sleep variables, mainly the slow wave sleep. They also indicate that a disorder of circadian time-keeping (a phase advance of the biological clock) characterizes some forms of affective illness.

Relationship between the Newcastle scale and sleep polysomnographic variables in major depression: a controlled study

In order to investigate the reliability of the endogenous concept of depressive illness with some sleep EEG parameters, we studied 39 male inpatients suffering from a nonbipolar major depressive episode (15 endogenous (MDDE) and 24 nonendogenous (MDDNE)) and 20 age and sex matched normal controls (C). All patients were diagnosed according to the Research Diagnostic Criteria (RDC) and the endogenous character of the episode was assessed with the Newcastle Endogenous Depression Diagnostic Index. We found significant differences for the following variables between the three groups (MDDE, MDDNE and C): sleep period time (SPT), REM latency, stage II, slow wave sleep (SWS), REM latency expressed as a continuous variable and REM latency expressed as a dichotomizing variable with a threshold of 50 min. These variables were used to compare the endogenous and the nonendogenous depressed patients and also the major depressed patients and the normal controls. Significant differences were observed between all depressed patients and control subjects for amount of SWS and REM latency which were both reduced in endogenous and nonendogenous depressed patients. No significant difference was observed between endogenous and nonendogenous depressed patients, except for the REM latency expressed with a threshold of 50 min (more frequently observed in endogenous depressed patients). Our data support the observation that SWS and REM latency are decreased in major depressive patients. However, in this age and sex controlled study, subtyping nonbipolar major depressive disorder for an endogenous character by the Newcastle Endogenous Depression Diagnostic Index (NEDDI) did not reveal further significant differences for sleep EEG variables, except for the shortening of the REM latency expressed as a dichotomizing variable.

TSH response to TRH and EEG sleep in non-bipolar major depression: a multivariate approach

The TSH response to TRH and selected sleep EEG variables were studied in a homogeneous sample of 280 non-bipolar major depressed inpatients (95 males and 185 females). The TSH response to TRH was blunted in 28% of the sample. delta max TSH was correlated negatively with age, Hamilton rating scale, Newcastle scale, percentage of wake, and positively with basal TSH, percentage of stage II, slow wave sleep, REM sleep and REM latency. delta max TSH was also lower in male patients and in patients suffering from an endogenous or a psychotic subtype of major depression. Basal TSH was only correlated negatively with the Newcastle score. In view of intercorrelations between all these variables, and because of the confounding effect of age, gender and severity on both the TSH response to TRH and sleep EEG variables, a multiple regression analysis was performed and demonstrated that basal TSH and gender were the two variables with the highest contribution to the delta max TSH variance, followed by age and the presence of psychotic symptoms. When controlling strictly for these significant effects, correlation with the severity or with the endogenous character of depression, and with sleep EEG parameters disappeared.

Regional cerebral blood flow in patients with affective disorders

Regional cerebral blood flow at rest was measured in 38 patients with major depressive disorders and 16 controls by SPECT with inhalation of xenon-133. All subjects had been withdrawn from medication. The mean hemispheric cerebral blood flow was not statistically different between the controls and the different subgroups of depressed patients defined either by biological markers or clinical characteristics. However, the predominantly cortical blood flow, measured on the outer cerebral rim of the third tomographic slice, was significantly lower on the left hemisphere in bipolar patients when compared with normals and unipolar patients. The same lateralisation was observed in patients with an endogenous depression according to the Newcastle scale.

Alprazolam and amitriptyline in the treatment of major depressive disorder: a double-blind clinical and sleep EEG study

This study was designed to compare the antidepressant effects of alprazolam and amitriptyline in a group of 30 inpatients suffering from a severe major endogenous depression, diagnosed by Research Diagnostic Criteria and the Newcastle Rating scale, and to examine the effects of alprazolam and amitriptyline on two biological markers of depression, the dexamethasone suppression test and sleep EEG parameters. The 6-week study was double-blind with a random allocation of treatment. Patients were treated with flexible doses of 4-9 mg of alprazolam and 100-225 mg of amitriptyline. After 4 weeks of treatment the antidepressant effects of amitriptyline significantly exceeded those of alprazolam, as measured on the Hamilton Rating Scale for Depression. There was a high drop-out rate in the alprazolam group because of ineffectiveness of treatment. Alprazolam showed similar effects on sleep parameters as amitriptyline: lengthening of the REM latency and a tendency to shorten stages 3 and 4 and stage REM. These negative clinical results should be interpreted with caution, because of the severity of our selection criteria, and should not be extended to all depressive disorders.

The dexamethasone suppression test in affective illnesses and schizophrenia: relationship with psychotic symptoms

The authors studied the dexamethasone suppression test (DST) on a series of 112 inpatients including 65 patients with major depressive disorder (21 bipolars: 4 with, 17 without psychotic symptoms; 44 unipolars: 13 with, 31 without psychotic symptoms), 15 patients with depressive disorder, 10 schizoaffective and 22 schizophrenic patients. Using different diagnostic criteria, they confirm the best performances of the DST in depression for the diagnosis of a major depressive disorder, primarily endogenous. They also examined the potential influence of psychotic symptoms, suicidal behavior and family history of affective illness on the DST. The only significant difference found is in the cortisol plasma level at 4 p.m. in bipolar patients with psychotic symptoms. That fact and the high rate of abnormality of the DST in schizoaffective and schizophrenic patients indicate that psychotic symptoms per se may play a role in a dysregulation of the hypothalamo-pituitary adrenal axis.

Further investigation of the dexamethasone suppression test in affective illnesses: relationship to clinical diagnosis and therapeutic response

The authors have studied the performances of the Dexamethasone Suppression Test (DST) in 107 hospitalized patients diagnosed according to the Research Diagnostic Criteria (RDC) and Feighner's criteria. The best performances of the DST are obtained for the diagnosis of primary depressed patients, suffering from a major depressive disorder. With the combination of these two diagnostic criteria, we found a sensitivity of 81%, a specificity of 81% and the diagnostic confidence of a positive test is 93%. Our study also shows 90% of abnormal DST results in schizoaffective disorder, depressed type, and no significant difference of the mean cortisol plasma levels at 4 p.m. after dexamethasone administration between depressed schizoaffective patients and major depressives. The finding of a better therapeutic response to antidepressive treatments in DST nonsuppressor patients than in suppressors is of interest for the predictive value of the DST in relation to treatment response.