The involvement of dehydroepiandrosterone (DHEA) and its sulfate ester (DHEAS) in blocking the therapeutic effect of electroconvulsive shocks in an animal model of depression

Dehydroepiandrosterone and Addiction

Drug addiction has a great negative influence on society, both social and economic burden. It was widely thought that addicts could choose to stop using drugs if only they had some self-control and principles. Nowadays, science has changed this view, defining drug addiction as a complex brain disease that affects behavior in many ways, both biological and psychological. Currently there is no ground-breaking reliable treatment for drug addiction. For more than a decade we are researching an alternative approach for intervention with drug craving and relapse to its usage, using DHEA, a well-being and antiaging food supplement. In this chapter we navigate through the significant therapeutic effect of DHEA on the brain circuits that control addiction and on behavioral performance both in animal models and addicts. We suggest that an integrative program of add-on DHEA treatment may further enable to dynamically evaluate the progress of rehabilitation of an individual patient, in a comprehensive assessment. Such a program may boost and support the detoxification and rehabilitation process, and help patients regain a normal life in a shorter amount of time.

Dehydroepiandrosterone Attenuates Cocaine-Seeking Behaviour Independently of Corticosterone Fluctuations

The neurosteroid dehydroepiandrosterone (DHEA) is involved in the pathophysiology of several psychiatric disorders, including cocaine addiction. We have previously shown that DHEA attenuates cocaine-seeking behaviour, and also that DHEA decreases corticosterone (CORT) levels in plasma and the prefrontal cortex. Previous studies have found that rats demonstrate cocaine-seeking behaviour only when the level of CORT reaches a minimum threshold. In the present study, we investigated whether the attenuating effect of DHEA on cocaine seeking is a result of it reducing CORT levels rather than a result of any unique neurosteroid properties. Rats received either daily DHEA injections (2 mg/kg, i.p.) alone, daily DHEA (2 mg/kg, i.p.) with CORT infusion (to maintain stable basal levels of CORT; 15 mg/kg, s.c.) or vehicle (i.p.) as control, throughout self-administration training and extinction sessions. We found that both DHEA-treated and DHEA + CORT-treated groups showed a significantly lower number of active lever presses compared to controls throughout training and extinction sessions, as well as at cocaine-primed reinstatement. DHEA-treated rats showed lower CORT levels throughout the experimental phases compared to DHEA + CORT-treated and control rats. Additionally, we show that DHEA administered to cocaine-trained rats throughout extinction sessions, or immediately before reinstatement, attenuated cocaine seeking. These findings indicate that DHEA attenuates cocaine-seeking behaviour independently of fluctuations in CORT levels.

Effects of electroconvulsive therapy on plasma levels of neuroactive steroids in inpatients with major depression

OBJECTIVE

Neuroactive steroids (NAS) are neuroactive molecules that have been shown to be associated with various psychiatric disorders. There are some inconclusive findings about the alteration in neuroactive steroid levels after the treatment of depression and ECT is still one of the most effective treatment choices for treatment resistant depression. Thus, we aimed to investigate the alterations of several NAS in plasma after ECT in inpatients with treatment resistant depression.

METHODS

In this study we enrolled 19 consecutive patients, 12 female and 7 male inpatients with major depression, who were not responding to medication, for whom ECT was Indicated, and were not taking any antidepressant treatment for at least a week prior to enrolment. We measured plasma progesterone, testosterone, pregnenolone, dehydroepiandrosterone (DHEA), dehydroepiandrosterone sulfate, and estradiol levels before and after ECT.

RESULTS

The mean age of the participants was 38.3 ± 9.4 years. The mean plasma neuroactive steroid levels were insignificant between baseline and post ECT in patients with treatment resistant depression.

CONCLUSIONS

ECT does not seem to influence plasma neuroactive steroid levels in patients with treatment resistant depression. Additionally, plasma dehydroepiandrosterone and pregnenolone levels might be associated with improvement in depressive symptoms after ECT.

Dehydroepiandrosterone stimulates nerve growth factor and brain derived neurotrophic factor in cortical neurons

Due to the increasing cases of neurodegenerative diseases in recent years, the eventual goal of nerve repair is very important. One approach for achieving a neuronal cell induction is by regenerative pharmacology. Nerve growth factor (NGF) and brain derived neurotrophic factor (BDNF) are neurotrophins that play roles in neuronal development, differentiation, and protection. On the other hand, dehydroepiandrosterone (DHEA) is a neurosteroid which has multiple actions in the nervous system. DHEA could be an important agent in regenerative pharmacology for neuronal differentiation during tissue regeneration. In this study, we investigated the possible role of DHEA to modulate NGF and BDNF production. The in vivo level of neurotrophins expression was demonstrated by ELISA in rat harvested brain cortex. Also neurotrophins expression after DHEA treatment was revealed by the increased neurite extension, immunostaining, and BrdU labeling in rats. Anti-NGF and anti-BDNF antibodies were used as suppressive agents on neurogenesis. The results showed that NGF and BDNF are overproduced after DHEA treatment but there is not any overexpression for NT-3 and NT-4. Also DHEA increased neurite extension and neural cell proliferation significantly. Overall, DHEA might induce NGF and BDNF neurotrophins overproduction in cortical neurons which promotes neural cell protection, survival, and proliferation.

An increase in spinal dehydroepiandrosterone sulfate (DHEAS) enhances NMDA-induced pain via phosphorylation of the NR1 subunit in mice: involvement of the sigma-1 receptor

Our laboratory has recently demonstrated that an increase in the spinal neurosteroid, dehydroepiandrosterone sulfate (DHEAS) facilitates nociception via the activation of sigma-1 receptors and/or the allosteric inhibition GABA(A) receptors. Several lines of evidence have suggested that DHEAS positively modulates N-methyl-d-aspartate (NMDA) receptor activity within the central nervous system. Moreover, we have demonstrated that the activation of sigma-1 receptors increases NMDA receptor activity. Since NMDA receptors play a key role in the enhancement of pain perception, the present study was designed to determine whether spinally administered DHEAS modulates NMDA receptor-mediated nociceptive activity and whether this effect is mediated by sigma-1 or GABA(A) receptors. Intrathecal (i.t.) DHEAS was found to significantly potentiate i.t. NMDA-induced spontaneous pain behaviors. Subsequent immunohistochemical analysis demonstrated that i.t. DHEAS also increased protein kinase C (PKC)- and protein kinase A (PKA)-dependent phosphorylation of the NMDA receptor subunit NR1 (pNR1), which was used as a marker of NMDA receptor sensitization. The sigma-1 receptor antagonist, BD-1047, but not the GABA(A) receptor agonist, muscimol, dose-dependently suppressed DHEAS's facilitatory effect on NMDA-induced nociception and pNR1 expression. In addition, pretreatment with either a PKC or PKA blocker significantly reduced the facilitatory effect of DHEAS on NMDA-induced nociception. Conversely the GABA(A) receptor antagonist, bicuculline did not affect NMDA-induced pain behavior or pNR1 expression. The results of this study suggest that the DHEAS-induced enhancement of NMDA-mediated nociception is dependent on an increase in PKC- and PKA-dependent pNR1. Moreover, this effect of DHEAS on NMDA receptor activity is mediated by the activation of spinal sigma-1 receptors and not through the inhibition of GABA(A) receptors.

Neural substrates of psychostimulant withdrawal-induced anhedonia

Psychostimulant drugs have powerful reinforcing and hedonic properties and are frequently abused. Cessation of psychostimulant administration results in a withdrawal syndrome characterized by anhedonia (i.e., an inability to experience pleasure). In humans, psychostimulant withdrawal-induced anhedonia can be debilitating and has been hypothesized to play an important role in relapse to drug use. Hence, understanding the neural substrates involved in psychostimulant withdrawal-induced anhedonia is essential. In this review, we first summarize the theoretical perspectives of psychostimulant withdrawal-induced anhedonia. Experimental procedures and measures used to assess anhedonia in experimental animals are also discussed. The review then focuses on neural substrates hypothesized to play an important role in anhedonia experienced after termination of psychostimulant administration, such as with cocaine, amphetamine-like drugs, and nicotine. Both neural substrates that have been extensively investigated and some that need further evaluation with respect to psychostimulant withdrawal-induced anhedonia are reviewed. In the context of reviewing the various neurosubstrates of psychostimulant withdrawal, we also discuss pharmacological medications that have been used to treat psychostimulant withdrawal in humans. This literature review indicates that great progress has been made in understanding the neural substrates of anhedonia associated with psychostimulant withdrawal. These advances in our understanding of the neurobiology of anhedonia may also shed light on the neurobiology of nondrug-induced anhedonia, such as that seen as a core symptom of depression and a negative symptom of schizophrenia.

Monoamines, BDNF, Dehydroepiandrosterone, DHEA-Sulfate, and Childhood Depression-An Animal Model Study

Basal levels of monoamines and DHEA in four main limbic brain regions were measured in prepubertal Wistar Kyoto (WKY) rats (a putative animal model of childhood depression). Basal levels of “Brain-Derived Neurotrophic Factor (BDNF)” were also determined in two regions in the hippocampus, compared with Wistar strain controls. In the second phase, we examined the responsiveness of prepubertal WKY rats to different types of chronic antidepressant treatments: Fluoxetine, Desipramine, and dehydroepiandrosterone sulfate (DHEAS). WKY prepubertal rats exhibited different monoamine levels in the limbic system, reduced DHEA levels in the VTA and lower levels of BDNF in the hippocampus CA3 region compared to controls. In prepubertal WKY rats, only treatment with DHEAS produced a statistically significant decrease in immobility, compared to saline-administered controls in the forced swim test. Wistar controls were not affected by any antidepressant. The results imply that DHEA(S) and BDNF may be involved in the pathophysiology and pharmacotherapy of childhood depression.

Intrathecal injection of the neurosteroid, DHEAS, produces mechanical allodynia in mice: involvement of spinal sigma-1 and GABA receptors

BACKGROUND AND PURPOSE

The neurosteroid, dehydroepiandrosterone sulphate (DHEAS) and its non-sulphated form, DHEA, are considered as crucial endogenous modulators of a number of important physiological events. Evidence suggests that DHEAS and DHEA modulate central nervous system-related functions by activating sigma-1 receptors and/or allosterically inhibiting gamma-aminobutyric acid receptor type A (GABA(A)) receptors. As both the sigma-1 receptor and the GABA(A) receptor play important roles in spinal pain transmission, the present study was designed to examine whether intrathecally injected DHEAS or DHEA affect nociceptive signalling at the spinal cord level.

EXPERIMENTAL APPROACH

We first determined whether intrathecal (i.t.) DHEA or DHEAS injection was able to affect nociceptive thresholds to peripheral mechanical stimulation and subsequently examined whether this effect was mediated by sigma-1 or the GABA(A) receptors.

KEY RESULTS

The i.t. DHEAS injection dose-dependently decreased the nociceptive threshold to mechanical stimulation, thus producing mechanical allodynia. Moreover, this DHEAS-induced mechanical allodynia was significantly reduced by administration of the sigma-1 receptor antagonist, BD-1047 or the GABA(A) receptor agonist, muscimol. Conversely, i.t. DHEA had no effect on mechanical sensitivity. However, when i.t. DHEA was combined with the GABA(A) receptor antagonist bicuculline, DHEA dose-dependently produced mechanical allodynia similar to that of DHEAS. This effect was blocked by BD-1047 and by muscimol.

CONCLUSIONS AND IMPLICATIONS

These findings indicate that i.t. injection of DHEAS produces mechanical allodynia and that the development of this mechanical allodynia is mediated by sigma-1 and GABA(A) receptors. The findings of this study raise several interesting questions for further investigations into the mechanisms underlying neurosteroid modulation of spinal pain transmission.

Electroconvulsive therapy and its different indications

In spite of recent developments in the pharmacotherapy of depressive disorders, the delay until clinical improvement can be achieved, and the considerable rate of nonresponse and nonremission, are major problems which remain unresolved. Electroconvulsive therapy (ECT) is a nonpharmacologic biological treatment which has been proven to be a highly effective treatment option, predominantly for depression, but also for schizophrenia and other indications. Though there is a lack of controlled investigations on long-term treatments, ECT can also be used for relapse prevention during maintenance therapies. The safety and tolerability of electroconvulsive treatment have been enhanced by the use of modified stimulation techniques and by progress in modern anesthesia. Thus, today a safe treatment can also be offered to patients with higher somatic risks. ECT still represents an important option, especially in the therapy of treatment-resistant psychiatric disorders after medication treatment failures. Earlier consideration of ECT may reduce the rate of chronic and difficult-to-treat psychiatric disorders.

Dehydroepiandrosterone and monoamines in the limbic system of a genetic animal model of childhood depression

Monoamines and dehydroepiandrosterone (DHEA) levels were measured in a genetic animal model for childhood depression in four subcortical structures: nucleus accumbens (Nac), ventral tegmental area (VTA), amygdala and hypothalamus. The "depressive-like" strain was the Flinders Sensitive Line (FSL), compared to their controls, Sprague-Dawley (SD) rats. Prepubertal FSL rats showed abnormal levels of only a few monoamines and their metabolites in these brain regions. This is in contrast to former studies, in which adult FSL rats exhibited significantly higher levels of all the monoamines and their metabolites measured. These different abnormal monoamine patterns between the "depressed" prepubertal rats and their adults, may help to explain why depressed children and adolescents fail to respond to antidepressant treatment as well as adults do. On the other hand, FSL prepubertal rats exhibited the same pattern of abnormal DHEA basal levels as was found in adults in previous experiments. The results from the current study may imply that treatment with DHEA could be a promising novel therapeutic option for depressed children and adolescents that fail to respond to common (monoaminergic) antidepressant treatments.

The relevance of neuroactive steroids in schizophrenia, depression, and anxiety disorders

1. Neuroactive steroids are steroid hormones that exert rapid, nongenomic effects at ligand-gated ion channels. There is increasing awareness of the possible role of these steroids in the pathology and manifestation of symptoms of psychiatric disorders. The aim of this paper is to review the current knowledge of neuroactive steroid functioning in the central nervous system, and to assess the role of neuroactive steroids in the pathophysiology and treatment of symptoms of schizophrenia, depression, and anxiety disorders. Particular emphasis will be placed on GABAA receptor modulation, given the extensive knowledge of the interactions between this receptor complex, neuroactive steroids, and psychiatric illness. 2. A brief description of neuroactive steroid metabolism is followed by a discussion of the interactions of neuroactive steroids with acute and chronic stress and the HPA axis. Preclinical and clinical studies related to psychiatric disorders that have been conducted on neuroactive steroids are also described. 3. Plasma concentrations of some neuroactive steroids are altered in individuals suffering from schizophrenia, depression, or anxiety disorders compared to values in healthy controls. Some drugs used to treat these disorders have been reported to alter plasma and brain concentrations in clinical and preclinical studies, respectively. 4. Further research is warranted into the role of neuroactive steroids in the pathophysiology of psychiatric illnesses and the possible role of these steroids in the successful treatment of these disorders.

Analysis of clinical symptomatology, extrapyramidal symptoms and neurocognitive dysfunction following dehydroepiandrosterone (DHEA) administration in olanzapine treated schizophrenia patients: a randomized, double-blind placebo controlled trial

Several studies have demonstrated the effective use of dehydroepiandrosterone (DHEA) in the management of mood, however studies of its use in psychosis remain limited. The aim of this study was to investigate for the first time efficacy of DHEA augmentation with standardized antipsychotic medication (olanzapine) and to explore effects of DHEA augmentation on side-effect profiles including weight gain, glucose tolerance, aggression, quality of life and neurocognitive function. Finally, we aimed to analyze any relationship between plasma levels and clinical response to DHEA administration. Forty patients with chronic schizophrenia stabilized on olanzapine were randomized in double-blind fashion to receive either DHEA (titrated up to 150mg) or placebo augmentation for a period of 12-weeks. Blood samples were collected at baseline, mid-study and study completion. Results indicated improvement of negative symptoms (SANS scale) even when baseline scores were controlled as a covariate. Some improvement in Parkinsonism and akathisia compared to baseline was seen in patients receiving DHEA. No change in psychosis as reflected by the PANSS was noted. Patients receiving DHEA appeared to demonstrate relatively stable glucose levels compared to controls at the end of the study. An improvement in cognitive performance (most notably memory), which did not reach significance due to low sample number, was observed following DHEA administration. Results further suggest preliminary evidence of involvement of the neurosteroid system in schizophrenia pathophysiology, and confirm initial "cautious" findings identifying an agent capable of improving negative symptoms and certain features of extrapyramidal side effects.

Positive correlation between anxiety severity and plasma levels of dehydroepiandrosterone sulfate in medication-free patients experiencing a major episode of depression

Although numerous studies have identified a correlation between dehydroepiandrosterone sulfate (DHEAS) levels and anxiety or depression, those findings remain controversial. The purpose of the present study was to determine whether a correlation exists between depression severity and anxiety severity and serum DHEAS concentrations in medication-free patients experiencing a major depressive episode. Twenty-eight medication-free major depressive outpatients (Hamilton Rating Scale for Depression 17 [HAM-D 17] score >or=17) were enrolled consecutively. Plasma DHEAS levels of all subjects were measured. Blood from subjects was drawn at 0900-1100 h Depression severity was assessed with the HAM-D 17 and the Hospital Anxiety and Depression Scale (HADS) depression subscale. Anxiety was assessed using the HADS anxiety subscale. Serum concentrations of DHEAS were measured immediately following the HAM-D 17 and HADS assessments. A significant, positive correlation was identified between HADS anxiety subscale total score and morning serum DHEAS concentration (P = 0.013) after controlling for age, gender and body mass index (BMI). No statistically significant correlations were found between depression ratings and morning serum DHEAS concentrations. This preliminary study provides pilot data indicating that morning serum DHEAS concentrations were positively correlated with HADS anxiety subscale score (anxiety severity) after controlling for age, gender and BMI in medication-free outpatients experiencing a major depressive episode. It is not known if morning serum DHEAS levels would show similar or dissimilar changes in non-depressed subjects. The present result needs subsequent replication.

DHEA, a neurosteroid, decreases cocaine self-administration and reinstatement of cocaine-seeking behavior in rats

Dehydroepiandrosterone (DHEA), which can act as a potential antidepressant in both animals and humans, appears to lower distress involved with cocaine withdrawal. In fact, a role for neurosteroids in modulation of substance-seeking behavior is becoming increasingly clear. Therefore, we tested the effects of DHEA on the self-administration of cocaine (1 mg/kg/infusion) by rats. At maintenance, a relatively low dose of exogenous DHEA (2 mg/kg; i.p.) attenuated cocaine self-administration after several days of chronic treatment. More than 2 weeks (19 days) of daily DHEA injections were required to decrease the cocaine-seeking behavior of rats to less than 20% of their maintenance levels. DHEA does not seem to decrease cocaine self-administration by increasing the reinforcing properties of the drug, as indicated by a cocaine dose-response determination. After being subjected to extinction conditions in the presence of DHEA, rats demonstrated a minimal response to acute exposure to cocaine (10 mg/kg), which indicated a protective effect of DHEA on relapse to cocaine usage. Our results suggest a potential role for the neurosteroid DHEA in controlling cocaine-seeking behavior, by reducing both the desire for cocaine usage and the incidence of relapse.

Difference in pre- and post-treatment plasma DHEA levels were significantly and positively correlated with difference in pre- and post-treatment Hamilton depression scores following successful therapy for major depression

OBJECTIVE

Clinical studies of endogenous concentrations of dehydroepiandrosterone (DHEA) and its relation to depression are limited. This study examined whether pre- and post-treatment changes in plasma DHEA levels are correlated with pre- and post-treatment differences in Hamilton depression scores following successful antidepressant therapy for major depression with venlafaxine XR.

METHOD

Thirty-four medication-free major depressive outpatients (Hamilton Rating Scale for Depression 17, HAM-D 17 score > or = 17) were treated with antidepressants. At baseline, plasma DHEA levels of all subjects were measured but only those who remitted (HAM-D 17 score < or = 7) before the end of this study had their plasma DHEA levels measured at remission-onset. Blood from subjects was drawn at 0900-1100 h. Depression severity was assessed with the HAM-D 17 scale at baseline, and on day 7, 14, 28, 56 and 84. Subjects were administered at minimum 75 mg/day venlafaxine XR until remission onset.

RESULTS

Fifteen patients remitted before the end of this study. Plasma DHEA levels decreased from baseline to remission was significant (P=0.017). After controlling for age and gender, pre- and post-treatment difference in Hamilton depression scores and the pre- and post-treatment difference in DHEA concentrations were significantly correlated (P=0.044).

CONCLUSION

This preliminary study provides the first clinical evidence identifying that difference in pre- and post-treatment plasma DHEA levels were significantly and positively correlated with difference in pre- and post-treatment Hamilton depression scores following successful therapy with venlafaxine XR for major depression in remitters; but non-remitters were not examined. It is not known if DHEA levels would show similar or dissimilar changes in non-remitters.

Dehydroepiandrosterone (DHEA) attenuates cocaine-seeking behavior in the self-administration model in rats

The aim of this study was to determine the possible involvement of the neurosteroid dehydroepiandrosterone (DHEA) in cocaine-seeking behavior in a self-administration model in rats. DHEA pretreatment (continued thereafter concomitantly with cocaine self-administration) attenuated cocaine-seeking behavior and elevated the levels of dopamine and serotonin in several brain regions relevant to cocaine addiction. Chronic cocaine self-administration induced elevation in brain DHEA, its sulfate ester, DHEAS, and pregnenolone. The increased brain DHEA following cocaine self-administration may serve as a compensatory protective mechanism geared to attenuate the craving for cocaine. Such anti-craving activity is further enhanced by DHEA treatment before and during cocaine self-administration.