Quetiapine blocks cocaine-induced enhancement of brain stimulation reward

A mechanistic overview of approaches for the treatment of psychostimulant dependence

Psychostimulant use disorder is a major health issue around the world with enormous individual, family-related and societal consequences, yet there are no effective pharmacological treatments available. In this review, a target-based overview of pharmacological treatments toward psychostimulant addiction will be presented. We will go through therapeutic approaches targeting different aspects of psychostimulant addiction with focus on three major areas; 1) drugs targeting signalling, and metabolism of the dopamine system, 2) drugs targeting either AMPA receptors or metabotropic glutamate receptors of the glutamate system and 3) drugs targeting the severe side-effects of quitting long-term psychostimulant use. For each of these major modes of intervention, findings from pre-clinical studies in rodents to clinical trials in humans will be listed, and future perspectives of the different treatment strategies as well as their potential side-effects will be discussed. Pharmaceuticals modulating the dopamine system, such as antipsychotics, DAT-inhibitors, and disulfiram, have shown some promising results. Cognitive enhancers have been found to increase aspects of behavioural control, and drugs targeting the glutamate system such as modulators of metabotropic glutamate receptors and AMPA receptors have provided interesting changes in relapse behaviour. Furthermore, CRF-antagonists directed toward alleviating the symptoms of the withdrawal stage have been examined with interesting resulting changes in behaviour. There are promising results investigating therapeutics for psychostimulant addiction, but further preclinical work and additional human studies with a more stratified patient selection are needed to prove sufficient evidence of efficacy and tolerability.

Quetiapine attenuates the acquisition of morphine-induced conditioned place preference and reduces ERK phosphorylation in the hippocampus and cerebral cortex

Background: Quetiapine is an atypical antipsychotic that antagonizes dopamine and serotonin receptors. It has been suggested that quetiapine can be used to treat substance use disorders, including opioid use disorder. Opioids modulate dopaminergic functions associated with conditioned reinforcement and these effects can be measured via the conditioned place preference (CPP) paradigm. Opioids' unconditioned effects are regulated by several proteins, including extracellular signal-regulated kinase (ERK) and cAMP-responsive element-binding (CREB).Objective: To assess the effect of quetiapine on morphine-induced CPP and motor activity levels, and on the levels of ERK and CREB proteins in the hippocampus and cerebral cortex.Methods: 42 male rats were exposed to a CPP protocol, in which they underwent a conditioning paradigm with saline, quetiapine (40 mg/kg), morphine (10 mg/kg), morphine plus quetiapine (10, 20, or 40 mg/kg), or morphine plus memantine (7.5 mg/kg, a positive control drug) (n = 6 per group). The rats were tested for CPP and exploratory activity. Levels of ERK and CREB proteins in the hippocampus and cerebral cortex were also measured.Results: Quetiapine co-administered with morphine inhibited morphine-induced CPP [F (6, 70) = 11.67, p < .001] and morphine's effects on motor activity (p < .001). Morphine enhanced ERK phosphorylation in the hippocampus (p < .001) and cerebral cortex (p < .001), an effect inhibited by quetiapine.Conclusion: Quetiapine attenuates morphine-induced CPP and locomotion and these effects are associated with a reduction of ERK phosphorylation in the hippocampus and cerebral cortex. These results suggest that quetiapine should be further explored as a potential treatment for opioid use disorder.

Quetiapine for the treatment of cocaine use disorder

BACKGROUND

Cocaine addiction continues to be a significant healthcare issue, yet there are no FDA approved medications for the treatment of cocaine use disorder within the United States.

METHODS

This 12-week, prospective, double-blind, randomized, placebo-controlled study examined the effectiveness of quetiapine (Seroquel XR™) versus matched placebo for the treatment of DSM-IV cocaine dependence in non-psychotic individuals. Subjects randomized to quetiapine (N = 29) were titrated up to a target dose of 400mg/day of quetiapine, while those in the placebo arm (N = 31) were given a matched placebo. All subjects had weekly clinic visits and a cognitive-behavioral therapy group session. Outcome measures included self-report of cocaine use and money spent on cocaine as well as urine drug screens (UDS).

RESULTS

The drop-out rate was substantial at 68%. Logistic regression analysis did not find significant differences between groups in predicting end-of trial abstinence, defined as three consecutive weekly negative UDS (13.7% in the quetiapine group versus 12.9% in the placebo group; p = .92). Based upon a repeated measures analysis of variance, subjects in this study, as a whole, demonstrated reductions in their self-reported use of cocaine, self-reported money spent on cocaine, and number of days per week using cocaine. However, the quetiapine group did not differ significantly from the placebo group.

CONCLUSIONS

This study did not find group differences between the quetiapine and placebo arms, suggesting that quetiapine is not an efficacious treatment for DSM-IV cocaine dependence.

Open-label pilot study of quetiapine treatment for cannabis dependence

BACKGROUND

There are no efficacious pharmacotherapies for cannabis dependence. The effects of quetiapine are well matched to the symptoms of cannabis withdrawal and could be useful in the treatment of cannabis dependence.

OBJECTIVES

To evaluate quetiapine for the treatment of cannabis dependence and determine the optimal dosing.

METHODS

In an eight-week open-label outpatient pilot trial, we evaluated the feasibility of quetiapine treatment for cannabis dependence in 15 outpatients. Quetiapine was gradually titrated to 600 mg or the maximum tolerated dose.

RESULTS

The mean study retention was 6.5 weeks (±2.3), with 67% of participants completing all eight weeks of the trial. The mean maximum dose achieved was 197 mg/day (range: 25-600 mg/day). Only two of the 15 participants were able to achieve the target dose of 600 mg daily. There were no serious adverse events and no participants were discontinued from the trial due to adverse effects. The most common reported adverse effects were fatigue (80% of participants) and somnolence (47%). From baseline to week 8, the modeled overall decrease in daily dollar value of marijuana was 76.3% (CI: 63.4%, 84.7%). Over the eight weeks of the study, there was a 46.9% (CI: 11%, 68.3%) decrease in urine tetrahydrocannabinol-9-carboxylic acid (THCOOH) levels.

CONCLUSIONS

These preliminary results are promising in that quetiapine treatment was tolerated by cannabis-dependent patients and associated with decreased cannabis use. The recommended maximum target dose for cannabis-dependent patients is 300 mg daily. These preliminary data support further evaluation of quetiapine as a treatment for cannabis dependence.

The effect of quetiapine (Seroquel™) on conditioned place preference and elevated plus maze tests in rats when administered alone and in combination with (+)-amphetamine

RATIONALE

Recent case reports describe recreational use of quetiapine and drug-seeking behaviour to obtain quetiapine, an atypical antipsychotic.

OBJECTIVE

We examined the hypothesis that quetiapine (10, 20 or 40 mg/kg) alone or co-administered with (+)-amphetamine (0.25, 0.5, 0.75 or 2.0 mg/kg) will affect reward and/or decrease anxiety in rats, as measured by conditioned place preference (CPP) and elevated plus maze (EPM) test, respectively.

RESULTS

Quetiapine (20 mg/kg) produced greater open arm time and entries in the EPM test compared to 10 and 40 mg/kg, and quetiapine (10 mg/kg) significantly increased open arm entries and time when co-administered with (+)-amphetamine (0.5 mg/kg) compared to (+)-amphetamine (0.5 mg/kg) alone, suggesting decreased anxiety. Quetiapine (10, 20 or 40 mg/kg) produced no CPP when administered alone; the lowest dose of quetiapine (10 mg/kg) reduced CPP produced by a low dose of (+)-amphetamine (0.25 mg/kg), but had no significant effect on CPP produced by a higher dose (0.5 mg/kg).

DISCUSSION

The quetiapine-induced anxiolytic effect in the EPM might explain why humans are misusing quetiapine and combining it with (+)-amphetamine. It is possible that humans experience an anxiolytic effect of the combined drugs and relatively unaltered rewarding effects of (+)-amphetamine. The results shed some light on the question of why humans are abusing and misusing quetiapine, despite its dopamine (DA) D2 receptor antagonism; it will be the task of future studies to identify the pharmacological mechanism mediating this behaviour.

Cannabinoids reward sensitivity in a neurodevelopmental animal model of schizophrenia: a brain stimulation reward study

The comorbidity schizophrenia and cannabis has a high prevalence. The consumption of cannabis is ten times higher among schizophrenia patients, suggesting that these patients could be differentially sensitive to its motivational effects. To study this question, we investigated the motivational effects of cannabinoid agonists using the brain stimulation reward paradigm and a neurodevelopmental model of schizophrenia: neonatal ventral hippocampus lesions (NVHL). Using the curve-shift paradigm, we first compared the effect single dose (0.75mg/kg) of amphetamine in sham and NVHL rats on reward and operant responding. Then, in different groups of NVHL and sham rats, we studied the effect of delta-9-tetrahydrocannabinnol (THC, 0.5mg/kg, i.p.) and WIN55,212-2 (WIN, 1 and 3mg/kg, i.p.) Rats were initially trained to self-administer an electrical stimulation to the posterio-medial mesencephalon. Once responding was stable, reward threshold defined as the frequency required to induce a half maximum response rate was measured before and after injection of the drug or the vehicle. Results show that amphetamine enhanced reward in sham and NVHL rats, an effect that was shorter in duration in NVHL rats. THC produced a weak attenuation of reward in sham rats while WIN produced a dose-dependent attenuation in NVHL; the attenuation effect of WIN was blocked by the cannabinoid antagonist, AM251. WIN also produced an attenuation of performance in sham and NVHL rats, and this effect was partially prevented by AM251. These results provide the additional evidence that the motivational effect of cannabinoids is altered in animals with a schizophrenia-like phenotype.

Short-term quetiapine treatment alters the use of reinforcement signals during risky decision-making and promotes the choice of negative expected values in healthy adult males

Effective decision-making can involve using environmental signals about the possible good and bad outcomes, and their probabilities, to select optimal actions. Problematic decision-making in psychiatric disorders, and particularly bipolar illness, may result from disrupted use of these reinforcement cues, leading to actions that reflect or precipitate pathological changes in mood. Previous experiments indicate that the processing of reinforcement cues while selecting between risky actions can be influenced by dopamine and serotonin activity. Quetiapine is an atypical antipsychotic agent with a complex pharmacology, including antagonist actions at 5-HT2A and, to a lesser extent, D2 receptors. Here, we investigated the effects of (short-term) treatment with quetiapine on the risky decision-making of healthy human adults. Twenty participants received 150 mg of quetiapine XL for 7 d, whereas 20 age- and IQ-matched participants received a placebo. On the eighth day, all participants completed a risky decision-making task that involved making a series of choices between two simultaneously presented gambles that differed in the magnitudes of their possible gains and losses, and the probabilities with which these outcomes were delivered. Quetiapine treatment was associated with a marked tendency to choose options with negative expected values compared with placebo treatment in male but not female participants. Our results demonstrate that antagonism of serotonin and dopamine receptor activity can alter the way individuals use information about gains and losses when selecting between risky actions, possibly reflecting gender-specific differences in risk attitudes. These effects may be beneficial by correcting decision-making biases that feature in mood disorders.

Blockade of ventral midbrain NMDA receptors enhances brain stimulation reward: a preferential role for GluN2A subunits

Ventral midbrain (VM) neurons that project to limbic structures play a role in reward and incentive motivation. It has been suggested that a reward-related signal is transmitted when the firing rate of VM dopamine neurons shifts from a tonic to a phasic mode. Since glutamate is necessary for this transduction process, it is likely to play a role in reward signaling. This study was aimed at determining the effect of VM N-Methyl-D-Aspartate (NMDA) receptor blockade on reward induced by electrical brain stimulation. Experiments were performed on rats trained to self-administer an electrical stimulation in the medial posterior mesencephalon. Reward thresholds were measured with the curve-shift paradigm before and after bilateral VM injections of the following NMDA receptor antagonists: R-CPP, 3-(R-2-Carboxypiperazin-4-yl)-propyl-1 phosphonic acid, (0, 20.6, 41.2 and 82.5 pmol/0.5 μl/side), PPPA, (2R,4S)-4-(3-Phosphonopropyl)-2-piperidinecarboxylic acid, (0, 0.825 and 1.65 nmol/0.5 μl/side) orRo04-5595, 1-[2-(4-Chlorophenyl)ethyl]-1,2,3,4-tetrqahydro-6-methoxy-2-methyl-7-isoquinolinol hydrochloride (0, 0.825, 1.65 nmol/0.5 μl/side). R-CPP and PPPA produced a dose and time dependent decrease in reward threshold, an effect that was, at some doses and times after the injection, accompanied by an increase in maximum responses. These effects were not observed with Ro04-5595 over the range of doses tested. While previous studies suggest a role for glutamate in reward signaling, the present results show that VM glutamate exerts a tonic inhibition on the reward-relevant pathway. The selectivity of Ro04-5595 for NMDA receptors composed of GluN2B subunits and the higher affinity of R-CPP and PPPA for GluN2A suggest that the inhibition is mediated by receptors composed of GluN2A subunits.

Opposite modulation of brain stimulation reward by NMDA and AMPA receptors in the ventral tegmental area

Previous studies have shown that blockade of ventral tegmental area (VTA) glutamate N-Methyl-D-Aspartate (NMDA) receptors induces reward, stimulates forward locomotion and enhances brain stimulation reward. Glutamate induces two types of excitatory response on VTA neurons, a fast and short lasting depolarization mediated by α-amino-3-hydroxy-5-methyl-4-isoxazole propionate (AMPA) receptors and a longer lasting depolarization mediated by NMDA receptors. A role for the two glutamate receptors in modulation of VTA neuronal activity is evidenced by the functional change in AMPA and NMDA synaptic responses that result from repeated exposure to reward. Since both receptors contribute to the action of glutamate on VTA neuronal activity, we studied the effects of VTA AMPA and NMDA receptor blockade on reward induced by electrical brain stimulation. Experiments were performed on rats trained to self-administer electrical pulses in the medial posterior mesencephalon. Reward thresholds were measured with the curve-shift paradigm before and for 2 h after bilateral VTA microinjections of the AMPA antagonist, NBQX (2,3,-Dioxo-6-nitro-1,2,3,4-tetrahydrobenzo(f)quinoxaline-7-sulfonamide, 0, 80, and 800 pmol/0.5 μl/side) and of a single dose (0.825 nmol/0.5 μl/side) of the NMDA antagonist, PPPA (2R,4S)-4-(3-Phosphonopropyl)-2-piperidinecarboxylic acid). NBQX produced a dose-dependent increase in reward threshold with no significant change in maximum rate of responding. Whereas PPPA injected at the same VTA sites produced a significant time dependent decrease in reward threshold and increase in maximum rate of responding. We found a negative correlation between the magnitude of the attenuation effect of NBQX and the enhancement effect of PPPA; moreover, NBQX and PPPA were most effective when injected, respectively, into the anterior and posterior VTA. These results suggest that glutamate acts on different receptor sub-types, most likely located on different VTA neurons, to modulate reward.

Cannabidiol inhibits the reward-facilitating effect of morphine: involvement of 5-HT1A receptors in the dorsal raphe nucleus

Cannabidiol is a non-psychotomimetic constituent of Cannabis sativa, which induces central effects in rodents. It has been shown that cannabidiol attenuates cue-induced reinstatement of heroin seeking. However, to the best of our knowledge, its effects on brain stimulation reward and the reward-facilitating effects of drugs of abuse have not yet been examined. Therefore, we investigated the effects of cannabidiol on brain reward function and on the reward-facilitating effect of morphine and cocaine using the intracranial self-stimulation (ICSS) paradigm. Rats were prepared with a stimulating electrode into the medial forebrain bundle (MFB), and a guide cannula into the dorsal raphe (microinjection experiments), and were trained to respond for electrical brain stimulation. A low dose of cannabidiol did not affect the reinforcing efficacy of brain stimulation, whereas higher doses significantly elevated the threshold frequency required for MFB ICSS. Both cocaine and morphine lowered ICSS thresholds. Cannabidiol inhibited the reward-facilitating effect of morphine, but not cocaine. This effect was reversed by pre-treatment with an intra-dorsal raphe injection of the selective 5-HT1A receptor antagonist WAY-100635. The present findings indicate that cannabidiol does not exhibit reinforcing properties in the ICSS paradigm at any of the doses tested, while it decreases the reward-facilitating effects of morphine. These effects were mediated by activation of 5-HT1A receptors in the dorsal raphe. Our results suggest that cannabidiol interferes with brain reward mechanisms responsible for the expression of the acute reinforcing properties of opioids, thus indicating that cannabidiol may be clinically useful in attenuating the rewarding effects of opioids.

Role of serotonin 5-HT2A and 5-HT2C receptors on brain stimulation reward and the reward-facilitating effect of cocaine

RATIONALE

The serotonin 5-HT(2A) and 5-HT(2C) receptors, which are found in abundance in the mesolimbocortical dopaminergic system, appear to modulate the behavioral effects of cocaine.

OBJECTIVES

The present series of studies set out to investigate the role of 5-HT(2A) and 5-HT(2C) receptors on brain reward and on the reward-facilitating effect of cocaine and localize the neural substrates within the mesolimbocortical dopaminergic system that are responsible for these effects.

METHODS

Male Sprague-Dawley rats were implanted with stimulating electrodes and bilateral cannulae for the experiments involving microinjections and were trained to respond to electrical stimulation. In the first study, we examined the effects of systemic administration of selective 5-HT(2A) and 5-HT(2C) receptor agonists (TCB-2 and WAY-161503) and antagonists (R-96544 and SB-242084) on intracranial self-stimulation (ICSS). In the second study, we examined the effectiveness of TCB-2, WAY-161503, R-96544, and SB-242084 in blocking the reward-facilitating effect of cocaine. In the third study, we examined the effects of intra-medial prefrontal cortex (mPFC), intra-nucleus accumbens (NAC), and intra-ventral tegmental area (VTA) injection of WAY-161503 on the reward-facilitating effect of cocaine.

RESULTS

Acute systemic administration of TCB-2 and WAY-161503 increased ICSS threshold. Systemic WAY-161503 attenuated the reward-facilitating effect of cocaine. This effect was reversed by pretreatment with SB-242084. Intracranial microinjections of WAY-161503 into the mPFC and the NAC shell/core, but not the VTA, attenuated the reward-facilitating effect of cocaine.

CONCLUSION

These data indicate that 5-HT(2C) receptors within the mPFC and the NAC modulate the reinforcing effects of cocaine and provide evidence that 5-HT(2C) receptor agonists could be a possible drug discovery target for the treatment of psychostimulant addiction.

The acute and chronic effects of combined antipsychotic-mood stabilizing treatment on the expression of cortical and striatal postsynaptic density genes

The detection of changes in postsynaptic gene expression after the administration of mood stabilizers, alone or in combination with antipsychotics, and antidepressants in animal models of drug treatment, may represent a valuable strategy to explore the molecular targets of the mainstay treatments for bipolar disorder. In this study we investigated, in both acute and chronic paradigms, the expression of specific postsynaptic density genes (Homer1a, Homer1b/c, and PSD95) and genes putatively implicated in mood stabilizers mechanism of action (GSK3b, ERK) after administration of first (haloperidol) or second generation antipsychotics (quetiapine 30 mg/kg), alone or in combination with valproate. Moreover, we compared the effects of an antidepressant agent widely used in bipolar depression (citalopram) with a low dose of quetiapine (15 mg/kg), which has been demonstrated to display antidepressant action in bipolar depression. In striatal regions, Homer1a expression was strongly induced by haloperidol compared to all the other treatments. Haloperidol plus valproate also markedly induced Homer1a, but to a significant lesser extent than haloperidol alone. Also in the chronic paradigm haloperidol, but not haloperidol plus valproate, induced Homer1a expression in all the subregions of the caudate-putamen and in the nucleus accumbens core. The high dose of quetiapine significantly induced Homer1a in anterior cingulated, premotor and motor subregions of the cortex, and the extent of induction was significantly higher as compared to the lower dose. Oppositely, Homer1a expression was decreased in the cortex by citalopram acute administration. ERK gene was upregulated in cortex and striatum by the acute treatment with valproate and with the combination of haloperidol or quetiapine plus valproate, whereas no significant differences were noticed in GSK3b expression among treatments. PSD95 showed a significant upregulation by acute citalopram and by haloperidol plus valproate in both cortical and subcortical regions. Haloperidol and quetiapine 30 mg/kg, oppositely, significantly reduced the expression of the gene in the cortex. In conclusion, these results suggest that the combined treatment with a typical or an atypical antipsychotic plus valproate may induce differential modulation of postsynaptic genes expression when compared to the effects of these drugs individually administered.

Acute quetiapine dose-dependently exacerbates anhedonia induced by withdrawal from escalating doses of d-amphetamine

Recent clinical studies show that the atypical antipsychotic medication, quetiapine, may be beneficial in the treatment of substance abuse by alleviating the withdrawal-negative affect stage of addiction. Since the effect of quetiapine on central reward function is largely unknown we studied its effects on brain stimulation reward in animals under withdrawal from escalating doses of d-amphetamine. Male Sprague-Dawley rats were trained to produce an operant response to receive a short train of electrical stimulation to the lateral hypothalamus. Measures of reward threshold were determined with the curve-shift method in different groups of rats before, and during four days after treatment with escalating doses (1 to 10mg/kg, i.p.) of d-amphetamine or its vehicle. At 24h of withdrawal, the effects of two doses of quetiapine (2 and 10mg/kg i.p.) were tested. Animals treated with d-amphetamine showed a 25% reward deficit at 24h of withdrawal, an effect that decreased progressively over the next three days. Quetiapine attenuated reward in the vehicle-control animals, and amplified the anhedonia at the moderate, but not the low, dose in the animals under withdrawal. These results show that acute treatment with clinically relevant doses of quetiapine for the treatment of schizophrenia may exacerbate anhedonia induced by amphetamine withdrawal. Further research should investigate whether repeated treatment with quetiapine has the ability to reverse amphetamine withdrawal-induced anhedonia.