Does DRD2 Taq1A Mediate Aripiprazole-Induced Gambling Disorder? A Pharmacogenetic Hypothesis

The pharmacological management of gambling disorder: if, when, and how

INTRODUCTION

Gambling disorder (GD) consists of a persistent, recurrent pattern of gambling that is associated with substantial distress or impairment. The etiology is multifactorial. GD frequently co-occurs with other psychiatric disorders and is often untreated. Different psychosocial interventions, particularly cognitive-behavioral therapy, are useful in the treatment of GD. Pharmacological therapy may also be helpful . No formal guidelines exist, and the management of the disease is often guided by few clinical elements.

AREAS COVERED

A literature search was performed using PubMed, Scopus, and Web of Science databases about treatment options for GD, considering both psychosocial treatments and available pharmacological ones.

EXPERT OPINION

The authors address whether and when it is appropriate to initiate pharmacological treatment for GD. They focus on providing clinicians with guidance on how to approach patients with GD in those situations where pharmacological therapy may be necessary. The reasons for the clinician to start thinking about a medication are examined. As specific traits in the psychopathology of GD may be managed with a strategic choice of the pharmacologic agent, the different available options are analyzed on the basis of their potential usefulness in GD. Issues that remain open about the pharmacological management of GD are summarized.

Serotonergic and dopaminergic control of impulsivity in gambling disorder

Gambling disorder (GD) is major public health issue. The disorder is often characterized by elevated impulsivity with evidence from analogous substance use disorders underlining prominent roles of brain monoamines in addiction susceptibility and outcome. Critically, GD allows the study of addiction mechanisms without the confounder of the effects of chronic substances. Here, we assessed the roles of striatal dopamine transporter binding and extrastriatal serotonin transporter binding in GD as a function of impulsivity using [¹²³ I]FP-CIT SPECT imaging in 20 older adults with GD (DSM-5 criteria; mean age 64 years) and 40 non-GD age- and sex-matched controls. We focused on GD in older individuals because there are prominent age-related changes in neurotransmitter function and because there are no reported neuroimaging studies of GD in older adults. Volume-of-interest-based and voxelwise analyses were performed. GD patients scored clearly higher on impulsivity and had higher tracer binding in the ventromedial prefrontal cortex than controls (p < 0.001), likely reflecting serotonin transporter activity. The binding in the medial prefrontal cortex positively correlated with impulsivity over the whole sample (r = 0.62, p < 0.001) as well as separately in GD patients (r = 0.46, p = 0.04) and controls (r = 0.52, p < 0.001). Striatal tracer binding, reflecting dopamine transporter activity was also positively correlated with impulsivity but showed no group differences. These findings highlight the role of prefrontal serotonergic function in GD and impulsivity. They identify cerebral coordinates of a potential target for neuromodulation for both GD and high impulsivity, a core phenotypic dimensional cognitive marker in addictions.

Suicidality and psychotic episodes after starting aripiprazole: two case reports

Switching antipsychotic medication must be done carefully to ensure patient safety and a successful response. Here, we present two major psychotic decompensations that occurred following a switch to aripiprazole in two patients with schizophrenia. Mr. X was treated with paliperidone and experienced residual anxiety. Thus, a switch to aripiprazole was planned with risperidone and a gradual decrease in paliperidone. Initially, an increase in aripiprazole resulted in remission of his residual symptoms. However, two weeks later, he presented an anxiety relapse with persecutory ideas which required hospitalization. Mr. Y, who was treated for many years with risperidone, presented with a treatment resistant psychotic episode. A switch to aripiprazole enhanced his clinical condition. Despite the initial improvement, soon after discharge from the hospital, the patient presented psychotic symptoms requiring home intervention. Ultimately, the patient in the midst of a delusional recrudescence, had killed himself when the health care team arrived. A strong dopamine antagonist may lead to the development of dopaminergic upregulation. The addition of a partial agonist to these hypersensitive neurotransmitter pathways could explain these episodes. We agree with previous reports and recommend careful management when switching from strong dopamine antagonists to aripiprazole.

Epigenetic Studies for Evaluation of NPS Toxicity: Focus on Synthetic Cannabinoids and Cathinones

In the recent decade, numerous new psychoactive substances (NPSs) have been added to the illicit drug market. These are synthetized to mimic the effects of classic drugs of abuse (i.e., cannabis, cocaine, etc.), with the purpose of bypassing substance legislations and increasing the pharmacotoxicological effects. To date, research into the acute pharmacological effects of new NPSs is ongoing and necessary in order to provide an appropriate contribution to public health. In fact, multiple examples of NPS-related acute intoxication and mortality have been recorded in the literature. Accordingly, several in vitro and in vivo studies have investigated the pharmacotoxicological profiles of these compounds, revealing that they can cause adverse effects involving various organ systems (i.e., cardiovascular, respiratory effects) and highlighting their potential increased consumption risks. In this sense, NPSs should be regarded as a complex issue that requires continuous monitoring. Moreover, knowledge of long-term NPS effects is lacking. Because genetic and environmental variables may impact NPS responses, epigenetics may aid in understanding the processes behind the harmful events induced by long-term NPS usage. Taken together, “pharmacoepigenomics” may provide a new field of combined study on genetic differences and epigenetic changes in drug reactions that might be predictive in forensic implications.

The prevalence and features of schizophrenia among individuals with gambling disorder

BACKGROUND-OBJECTIVES

Few studies have analyzed the comorbid presence of gambling disorder (GD) with schizophrenia, its sociodemographic correlates and clinical implications. This study estimated the prevalence of the dual diagnosis (GD with schizophrenia) and the differences in the profiles of patients with and without the dual condition.

METHOD

The sample included n = 3,754 patients consecutively accepted for treatment for GD. Sociodemographics, gambling-related variables, psychopathological state and personality traits were assessed and compared between the groups.

RESULTS

The prevalence of schizophrenia within patients who met clinical criteria for GD was 4.4% (95% confidence interval: 3.8%-5.1%). Variables related to the dual presence of GD with schizophrenia were single marital status, lower education level, inactive working status, socioeconomic disadvantage, younger age, earlier onset of gambling problems, worse global psychopathological state and more dysfunctional personality profile (higher level in harm avoidance and lower level in cooperativeness, reward dependence, persistence and self-directedness).

CONCLUSION

The presence of schizophrenia among patients with GD was around 4 times higher than the prevalence rate estimated in the reference general population. The differences in the profiles of GD patients with and without schizophrenia suggest that individuals with the dual diagnosis condition require unique assessment considerations and tailored treatment interventions specifically designed for the clinical and functioning higher risk.