Arginine vasopressin, but not corticotropin releasing factor, is a potent stimulator of adrenocorticotropic hormone following electroconvulsive treatment

Electroconvulsive Therapy: Mechanisms of Action, Clinical Considerations, and Future Directions

LEARNING OBJECTIVES

• Outline and discuss the fundamental physiologic, cellular, and molecular mechanisms of ECT to devise strategies to optimize therapeutic outcomes• Summarize the overview of ECT, its efficacy in treating depression, the known effects on cognition, evidence of mechanisms, and future directions.

ABSTRACT

Electroconvulsive therapy (ECT) is the most effective treatment for a variety of psychiatric illnesses, including treatment-resistant depression, bipolar depression, mania, catatonia, and clozapine-resistant schizophrenia. ECT is a medical and psychiatric procedure whereby electrical current is delivered to the brain under general anesthesia to induce a generalized seizure. ECT has evolved a great deal since the 1930s. Though it has been optimized for safety and to reduce adverse effects on cognition, issues persist. There is a need to understand fundamental physiologic, cellular, and molecular mechanisms of ECT to devise strategies to optimize therapeutic outcomes. Clinical trials that set out to adjust parameters, electrode placement, adjunctive medications, and patient selection are critical steps towards the goal of improving outcomes with ECT. This narrative review provides an overview of ECT, its efficacy in treating depression, its known effects on cognition, evidence of its mechanisms, and future directions.

Electroconvulsive therapy, depression, the immune system and inflammation: A systematic review

BACKGROUND

The management and treatment of major depressive disorder are major public health challenges, the lifetime prevalence of this illness being 4.4%-20% in the general population. Major depressive disorder and treatment resistant depression appear to be, in part, related to a dysfunction of the immune response. Among the treatments for depression ECT occupies an important place. The underlying cerebral mechanisms of ECT remain unclear.

OBJECTIVES/HYPOTHESIS

The aim of this review is to survey the potential actions of ECT on the immuno-inflammatory cascade activated during depression.

METHODS

A systematic search of the literature was carried out, using the bibliographic search engines PubMed and Embase. The search covered articles published up until october 2017. The following MESH terms were used: Electroconvulsive therapy AND (inflammation OR immune OR immunology).

RESULTS

Our review shows that there is an acute immuno-inflammatory response immediately following an ECT session. There is an acute stress reaction. Studies show an increase in the plasma levels of cortisol and of interleukins 1 and 6. However, at the end of the course of treatment, ECT produces, in the long term, a fall in the plasma level of cortisol, a reduction in the levels of TNF alpha and interleukin 6.

LIMITATIONS

One of the limitations of this review is that a large number of studies are relatively old, with small sample sizes and methodological bias.

CONCLUSION

Advances in knowledge of the immuno-inflammatory component of depression seem to be paving the way towards models to explain the mechanism of action of ECT.

Effects of Electroconvulsive Therapy on Some Inflammatory Factors in Patients With Treatment-Resistant Schizophrenia

OBJECTIVES

Electroconvulsive therapy (ECT) is the most effective option for several psychiatric conditions, including treatment-resistant schizophrenia. However, little is known about the molecular mechanism of action of ECT. The link between inflammatory system and schizophrenia is the focus of recent studies. However, the impact of ECT on inflammatory functioning in this disorder remains elusive. Whether ECT could modulate inflammatory factors in patients with schizophrenia was examined.

METHODS

Plasma levels of interleukin-4 (IL-4), transforming growth factor-β (TGF-β), myeloperoxidase (MPO), and nuclear factor-κB (NF-κB) activation were analyzed in 20 schizophrenic patients, mainly with resistant to antipsychotic medication disorders, and in 20 sex- and age-matched healthy controls. Disease severity was evaluated using the Brief Psychiatric Rating Scale. All patients were followed with measurement of the inflammatory factors before and after ECT treatment and compared with the controls.

RESULTS

Patients with schizophrenia had markedly raised NF-κB and but decreased TGF-β levels compared with healthy controls. On the other hand, no significant differences were found for the levels of IL-4 and MPO levels. The clinical improvement during repeated ECT was accompanied by a gradual and significant increase in IL-4 and TGF-β level, but MPO and NF-κB activation were left unaffected. Increases in TGF-β were negatively correlated with the change in Brief Psychiatric Rating Scale scores after ECT.

CONCLUSIONS

It is shown that ECT, while increasing the anti-inflammatory response such as the levels of IL-4 and TGF-β, it did not affect the levels of MPO and NF-κB activation in this study.

Variation of plasma cortisol levels in patients with depression after treatment with bilateral electroconvulsive therapy

Introduction: More than 60 years after the introduction of modern psychopharmacology, electroconvulsive therapy (ECT) continues to be an essential therapeutic modality in the treatment of mental disorders, but its mechanism of action remains unclear. Hormones play an essential role in the development and expression of a series of behavioral changes. One aspect of the influence of hormones on behavior is their potential contribution to the pathophysiology of psychiatric disorders and the mechanism of action of psychotropic drugs and ECT.Objective: We measured blood levels of the hormone cortisol in patients with unipolar depression according to the Diagnostic and Statistical Manual of Mental Disorders, 4th edition (DSM-IV) and compared results with levels found in healthy adults.Method: Blood cortisol levels were measured before the beginning of treatment with ECT, at the seventh session, and at the last session, at treatment completion. Depression symptoms were assessed using the Beck Depression Inventory (BDI).Results: Cortisol levels remained stable in both men and women between the seventh and the last sessions of ECT; values ranged from 0.686±9.6330 g/dL for women, and there was a mean decrease of 5.825±6.0780 g/dL (p = 0.024). Mean number of ECT sessions was 12. After the seventh and the last ECT sessions, patients with depression and individuals in the control group had similar cortisol levels, whereas BDI scores remained different.Conclusion: Cortisol levels decreased during ECT treatment. ECT seems to act as a regulator of the hypothalamic-pituitaryadrenal axis.

Electroconvulsive therapy has acute immunological and neuroendocrine effects in patients with major depressive disorder

BACKGROUND

Major depressive disorder is associated with alterations in the neuroendocrine as well as immune system. Few studies examined the impact of electroconvulsive therapy (ECT) on these systems in patients with major depressive disorder (MDD).

METHODS

In this explorative study 12 patients suffering from medication-resistant MDD or MDD with psychotic features were studied during the first, the fifth and eleventh session of ECT. Blood samples were taken immediately prior to the electrostimulus and 5, 15 and 30 min after the electrostimulus to assess various lipopolysaccharide (LPS) stimulated or T-cell mitogen induced cytokines, immune cell numbers, Natural Killer cell activity, cortisol and ACTH.

RESULTS

Acute ECT increased the LPS-stimulated production of the cytokines IL-6 and TNF-α by peripheral monocytes but not the production of the anti-inflammatory cytokine IL-10. Acute ECT decreased T cell mitogen-induced levels of IFN-γ but IL-10 and IL-4 levels were left unaffected while NK cell activity increased momentarily but significantly. Cortisol and ACTH rose significantly after electrostimulus. Repeated ECT had no significant effect on any of the parameters.

LIMITATIONS

The study had a small group size. Also the patient group was heterogeneous as it consisted of patients with therapy-resistant depression with or without psychotic features.

CONCLUSIONS

Results suggest that acute ECT is associated with transient immunological and neuro-endocrine changes, while repeated ECT does not have an additive effect on the immune and neuroendocrine functions.

How does electroconvulsive therapy work? Theories on its mechanism

This article reviews 3 current theories of electroconvulsive therapy (ECT). One theory points to generalized seizures as essential for the therapeutic efficacy of ECT. Another theory highlights the normalization of neuroendocrine dysfunction in melancholic depression as a result of ECT. A third theory is based on recent findings of increased hippocampal neurogenesis and synaptogenesis in experimental animals given electroconvulsive seizures. Presently, the endocrine theory has the strongest foundation to explain the working mechanism of ECT.

Electroconvulsive therapy in patients taking steroid medication: should supplemental doses be given on the days of treatment?

Patients who take chronic steroid medication are often prescribed extra "stress doses" before procedures involving general anesthesia. The rationale for this practice is that the chronic steroid use has suppressed the ability of the endogenous hypothalamic-pituitary-adrenal steroid stress-reactivity system to handle the systemic stress of surgery. Whether the stress of treatments is sufficient enough to warrant this practice in electroconvulsive therapy (ECT) has not been broached in the literature. In this case series, we describe our experience treating 27 ECT patients taking prednisone. We conclude that use of "stress doses" of extra steroid medication is unnecessary in ECT practice and recommend that patients receive their usual morning dose of steroid before ECT treatments.

ECT of major depressed patients in relation to biological and clinical variables: a brief overview

The knowledge that spontaneous or induced convulsions can improve mental disorders has been present for several centuries. electroconvulsive therapy (ECT) has undergone fundamental changes since its introduction, and in the last 15-20 years there has been a legitimate renewal of interest for this therapy. Today the indications for use of ECT seem well codified, and its technique and practices have evolved considerably. It is now firmly established as an important and effective method of treating certain severe forms of depression. However, still very little is known about the mechanism of ECT. In this paper, first, we will give a short overview as to how far we have got concerning ECT in relation to various clinical and biological variables. Second, we will describe ECT in relation to electroencephalographic (EEG) technique and clinical outcome as well as give some proposals as to how to go on with the data analysis of EEG. In conclusion, the superior effect of ECT compared to other antidepressives in severe depression may depend on neurochemical and neurobiological cascade effects initiated by repeated treatments. Above all, ECT offers a unique experimental opportunity to study how neuromodulation of the major transmitter systems may be involved in brain dynamics and alteration of connectivity.

Blood concentrations of vasopressin, neuropeptide FF and prolactin are increased by high-dose right unilateral ECT

Electroconvulsive therapy (ECT) is known to stimulate subcortical brain regions and release hormones from the anterior and the posterior pituitary. To enhance the subcortical effect of ECT and the neuroendocrinological response we used high dose right unilateral ECT (RUL-ECT) in 11 depressive patients and studied its effect on the release of vasopressin, prolactin and neuropeptide FF. The RUL ECT stimulus for all studied patients was 5 times the individual seizure threshold and it led to immediate release of vasopressin in all studied patients. The release of prolactin was less uniform however in accordance with results from earlier studies. The ECT also stimulated a NPFF secretion peak that came approximately 5 min after ECT stimulus and preceded the prolactin peak. The maximal elevations in circulating vasopressin and prolactin concentrations were 680% and 950%, respectively. The neuropeptide FF concentration increased by 100% after ECT. There was a second rise in NPFF concentration at 25 min after the ECT treatment. The increases in all peptide concentrations were significant, but were not correlated with each other. The neuropeptide FF concentration returned to baseline level at 10 min and the vasopressin concentration at 25 min after ECT. The prolactin concentration remained increased during the 30 min follow up period. Our results complete earlier finding on ECT stimulated vasopressin and prolactin release and show that high intensity RUL-ECT releases neuropeptide FF into human blood. The modest rise of circulating NFFF most likely represents leakage from the CNS.

ECT in Parkinson's disease. Changes in motor symptoms, monoamine metabolites and neuropeptides

Electroconvulsive therapy (ECT) was given to 16 non-depressed, non-demented patients with advanced Parkinson's disease (PD). In all the patients an antiparkinsonian effect was seen, lasting for 18 months in one patient, 3-5 months in seven patients, and a few days to four weeks in eight patients. After ECT the levels of homovanillic acid and neuropeptide Y in cerebrospinal fluid (CSF) were significantly increased. The eight patients with long lasting motor improvement after ECT had significantly lower CSF-3-methoxy-4-hydroxyphenylglycol compared to the group with short lasting improvement. Five patients developed transitory mental confusion after ECT. In these patients, and in no others, a high albumin-ratio was found already before ECT was given - an indication of blood CSF barrier damage. Our results suggest that ECT is valuable in patients with drug refractory PD or PD with intolerance to antiparkinsonian drugs.

Seasonal changes in the levels of antidiuretic hormone and melatonin in the elderly

Antidiuretic hormone (ADH) and melatonin in plasma were measured every 4 hr during a 24-hr period in 69 elderly volunteers (42 males and 27 females) aged 75.6 +/- 8.8 years (+/- SD) and 73.5 +/- 9.5 years, respectively. The population was divided into three groups, which were examined February 27-28, April 25-26, and November 14-15. For the males, the mean ADH level during 24 hr was lowest in April and highest in November with a level five times higher than in April. The ADH level in February was about three times higher that in April. Females did not show any seasonal variation in the ADH system. The melatonin levels were lowest in November, higher in February, and even higher in April in both male and female volunteers. The ADH increased with age in males (R2 = 0.13; P < 0.05) but not in females (R2 = 0.07; NS). The melatonin concentration decreased with age for the whole group, aged 60-98 years.

Kindled seizures induce a long-term increase in vasopressin mRNA

Neuroendocrine disturbances are among the significant problems associated with animal and human seizures. To investigate the mechanisms for these disturbances, we examined changes in the expression of vasopressin (VP) mRNA in the hypothalamic magnocellular neuroendocrine cells of rats after amygdala kindled seizures, a model for temporal lobe epilepsy. A prominent increase in VP mRNA was found in the supraoptic nucleus of kindled animals by one week after the last seizure which persisted for at least 4 months. The increase occurred bilaterally in the SON and remained unchanged despite the absence of further stimulation, seizures or change in body fluid homeostasis. Since the VP mRNA change after kindling correlated with the duration of afterdischarge but not the number of amygdala stimuli the change appears to be an effect of the seizure. This chronic increase in VP mRNA appears to reflect a change in neuroendocrine gene expression and may identify an important new mechanism of plasticity that contributes to the neuroendocrine disturbances accompanying epilepsy.

Reduced concentrations of galanin, arginine vasopressin, neuropeptide Y and peptide YY in the temporal cortex but not in the hypothalamus of brains from schizophrenics

Postmortem investigations were performed in brains from 14 schizophrenic patients and 21 controls matched for age and autopsy latency. Concentrations of galanin, delta-sleep-inducing peptide (DSIP), corticotropin-releasing factor (CRF), arginine vasopressin (AVP), neuropeptide Y (NPY) and peptide YY (PYY) were determined in the hypothalamus and grey matter from the temporal cortex. A significant positive correlation between age and the concentrations of galanin and CRF was found in the controls. No sex differences were found except a higher mean of CRF in the hypothalamus of the women. In the temporal cortex of the schizophrenic brains, galanin, AVP, NPY and PYY were significantly reduced. DSIP reduction only bordered on significance. CRF was not reduced. Comparing neuroleptic-treated vs non-treated schizophrenics, the treatment factor could not explain the reduced concentrations of neuropeptides in the temporal lobe. A comparison of controls with schizophrenics showed no significant differences in hypothalamic neuropeptide concentrations.

Diurnal variation in the levels of antidiuretic hormone in the elderly

The secretion of antidiuretic hormone (ADH) and the serum osmolality were measured at 4-h intervals throughout a 24-h period in 69 healthy elderly volunteers. In male subjects the concentrations of plasma ADH were always twofold higher than in female subjects. The normal diurnal rhythm, with increased ADH secretion during the night, was not seen in this group of elderly subjects, with the exception of elderly men who did not urinate during the night, in whom a substantial increase in plasma ADH levels occurred. In as many as 25% of all the ADH measurements performed (n = 455) ADH was not detectable by the method used. The lack of a definite diurnal rhythm in most of the elderly subjects could to some extent explain the increased diuresis during the night in the elderly.

Corticotropin, cortisol and beta-endorphin responses to the human corticotropin-releasing hormone during melancholia and after unilateral electroconvulsive therapy

Previous research in neuroendocrinology has evidenced that hyperactivity of the hypothalamic-pituitary-adrenal axis (HPA) depends on hypersecretion of corticotropin-releasing hormone (CRH). The aim of this study was to investigate the activity of HPA before and after recovery in depressed patients treated with electroconvulsive therapy (ECT). An h-CRH-stimulation test was performed on 2 occasions with examination of the HPA axis before ECT treatment during episodes of major depressive disorders with melancholia, and during the recovery phase after treatment. The results showed that patients during depression had significantly higher plasma levels of cortisol at 15 and 30 min after h-CRH-administration than after recovery. Depressed patients had significantly higher plasma levels of beta-endorphin 30 min after h-CRH-stimulation. The results are in agreement with previous studies, which have shown hypercortisolemia during depression. A possible hypersecretion of CRH may explain the effect on cortisol and beta-endorphin. No significant differences were found between cumulative responses of corticotropin, cortisol and beta-endorphin, calculated as the areas under the concentration curves.

Dynamic training and circulating levels of corticotropin-releasing factor, beta-lipotropin and beta-endorphin in rheumatoid arthritis

The study aimed at evaluating the effects of a dynamic training program on circulating levels of corticotropin-releasing factor (CRF), beta-lipotropin (beta-LPH), and beta-endorphin (beta-EP) in 8 patients (5 females and 3 males, aged 39-65 years) with classical/definite rheumatoid arthritis (RA). Blood samples were collected immediately before, in the middle of, and after a 6-week high-intensity training period as well as after a subsequent 1-year period of low-intensity training. In addition, baseline data were obtained 3 weeks before the start of the training program. Use of multivariate analyses of variance, and of analyses of variance of contrast variables, indicated a short-term effect of the high-intensity training program for beta-EP with increased levels (P less than 0.05) between the 3rd and the 6th weeks, no significant differences being obtained for CRF or beta-LPH here. Corresponding analyses with regard to the combined high and low-intensity training program revealed CRF (P less than 0.01), and beta-LPH (P less than 0.01) levels to increase over time, no long-term effect being found for beta-EP. Despite the intensity of the dynamic training program, no change was found in pain experience as measured on a visual analogue scale.

Disturbance of the 5-hydroxytryptamine metabolism in brains from patients with Alzheimer's dementia

The 5-hydroxytryptamine (5-HT) system in the human brain is sensitive to aging. In dementia of the Alzheimer type (AD/SDAT), there are significantly reduced concentrations of 5-HT and 5-hydroxyindoleacetic acid (5-HIAA). 5-HT-sensitive imipramine binding is reduced by almost 50%, indicating a loss of presynaptic 5-HT terminals. There also seems to be reduced tryptophan hydroxylase activity in some brain areas. In cerebrospinal fluid (CSF) from AD/SDAT patients, the concentration of 5-HIAA is reduced, and the accumulation of 5-HIAA after probenecid loading is diminished. Biochemical findings together with structural findings in the raphe nuclei indicate that the disturbance of the 5-HT system is of the same magnitude as the disturbance of the cholinergic system. Reduced activity in the 5-HT system may be of importance for activity in the hypothalamus. There is an increased concentration of arginine vasopressin, which may explain the increased activity in the hypothalamic-pituitary-adrenal axis seen in patients with AD/SDAT. This activity is reduced when a selective 5-HT reuptake blocker is given. Pharmacological treatment with 5-HT reuptake blockers improves emotional disturbances, confusion, anxiety and depressed mood in patients with AD/SDAT.

Influence of cysteamine and cysteine on open-field behaviour, and on brain concentrations of catecholamines, somatostatin, neuropeptide Y, and corticotropin releasing hormone in the rat

Cysteamine (1.95 or 3.90 mM/kg) administered subcutaneously (sc) markedly decreased the open-field activity of the rats, while the structurally related amino acid cysteine had only minor influence. Cysteamine (1.95 or 3.90 mM/kg) reduced the noradrenaline and increased the dopamine and dihydroxyphenyl acetic acid (DOPAC) levels in the hypothalamus. In striatum the drug decreased both the noradrenaline (1.95 or 3.90 mM/kg) and dopamine (3.90 mM/kg) levels without influencing the DOPAC content. Neither the hypothalamic nor the striatal catecholamines are influenced by administration of equimolar doses of cysteine. Cysteamine (1.95 or 3.90 mM/kg) decreased the somatostatin levels both in the hypothalamus and in the striatum without influencing neuropeptide Y (NPY) and corticotropin releasing hormone (CRH) concentrations. Cysteine administered in equimolar doses did not influence the peptide levels in these brain structures. These data suggest that the cysteamine-induced behavioural changes are related to the decrease of brain noradrenaline and somatostatin concentrations. The structurally related amino acid cysteine does not influence the behaviour or the central monoaminergic and peptidergic concentrations in the hypothalamus and striatum of rats.

Reduction of immunoreactive ACTH in plasma following intravenous injection of delta sleep-inducing peptide in man

Eleven healthy male volunteers, ages 25-39 years, received a single dose of synthetic delta sleep-inducing peptide (DSIP) (25 nmol/kg BW) or saline intravenously in a randomized cross-over, double-blind study. The concentrations of neuropeptides related to the hypothalamic pituitary-adrenal (HPA) axis and cortisol were examined in serial plasma samples. In addition, cortisol and monoamine metabolites were determined in urine. A significant reduction of ACTH-like immunoreactivity (ACTH-LI) in plasma was detected for at least 3 hr after the DSIP injection, compared to the control subjects, in whom a slightly elevated concentration of ACTH-LI occurred. Plasma cortisol levels were unaffected and followed the normal diurnal decline. No differences in urinary cortisol or monoamine metabolite concentrations occurred between the two groups. The results indicate an inhibitory action of DSIP on ACTH secretion in man, as previously suggested by animal experiments.