Impulse control disorders: updated review of clinical characteristics and pharmacological management

Neural correlates of impulsivity in amphetamine use disorder

Impulsivity is a trait associated with several psychiatric conditions, not least addictive disorders. While the neural mechanisms behind certain aspects of impulsivity have been studied extensively, there are few imaging studies examining this neurocircuitry in populations with substance use disorders. Therefore, we aimed to examine the functional connectivity of relevant neural networks, and their possible association with trait impulsivity, in a sample with severe amphetamine use disorder and a control group of healthy subjects. We used data collected in a randomized clinical trial studying the acute effects of oral naltrexone in amphetamine use disorder. Our final sample included 32 amphetamine users and 27 healthy controls. Trait impulsivity was rated with the Barratt Impulsiveness Scale-11, and functional connectivity was measured during resting-state fMRI, looking specifically at networks involving prefrontal regions previously implicated in studies of impulsivity. Amphetamine users had higher subjective ratings of impulsivity as compared to healthy controls, and these scores correlated positively with a wide-spread prefrontal hyperconnectivity that was found among the amphetamine users. These findings highlight the importance of aberrant prefrontal function in severe addiction.

Nonmotor Symptoms and Impulse Control Disorders in Parkinson's Disease Patients in India: A Cross-sectional Study

INTRODUCTION

Parkinson's disease (PD) is a prevalent neurodegenerative disorder with significant nonmotor symptom (NMS) burden, including impulse control disorders. This study aimed to comprehensively evaluate NMS and impulse control disorders in PD patients under primary care.

MATERIALS AND METHODS

A descriptive cross-sectional study was conducted on 32 PD patients and evaluated using standardized assessment tools. Demographics, comorbidities, and symptom burdens were recorded. Evaluation tools included the Hoehn and Yahr Scale, REM Sleep Behavior Disorder assessment, Geriatric Depression Scale, Montreal Cognitive Assessment scale for cognitive impairment, NMS scale, and identification of impulse control disorders.

RESULTS

In PD, comorbidities were prevalent (84%), and most were at Hoehn and Yahr Stages 2 and 3. REM Sleep Behavior Disorder was present in 28.12%, with 5 receiving clonazepam treatment. Depression affected 28.12%, with 5 receiving pharmacological treatment. Cognitive impairment was notable in 9 patients. NMS burden was high, with varying severity. Impulse control disorders were limited, whereas one case of dopamine dysregulation syndrome was identified.

DISCUSSION

This primary care-based study in India assessed NMS and impulse control disorders in PD patients, highlighting comorbidities and management opportunities. The study's strength lies in evaluating an unselected primary care population, whereas limitations include small sample size.

CONCLUSION

This study emphasizes the importance of primary care physicians in monitoring and managing NMS in PD patients. Impulse control disorders and cognitive impairment are critical aspects that need attention. The findings support an integrated approach involving health-care professionals across various disciplines to provide holistic care for PD patients.

Rats Lacking the Dopamine Transporter Display Inflexibility in Innate and Learned Behavior

Playing a key role in the organization of striatal motor output, the dopamine (DA)-ergic system regulates both innate and complex learned behaviors. Growing evidence clearly indicates the involvement of the DA-ergic system in different forms of repetitive (perseverative) behavior. Some of these behaviors accompany such disorders as obsessive-compulsive disorder (OCD), Tourette's syndrome, schizophrenia, and addiction. In this study, we have traced how the inflexibility of repetitive reactions in the recently developed animal model of hyper-DA-ergia, dopamine transporter knockout rats (DAT-KO rats), affects the realization of innate behavior (grooming) and the learning of spatial (learning and reversal learning in T-maze) and non-spatial (extinction of operant reaction) tasks. We found that the microstructure of grooming in DAT-KO rats significantly differed in comparison to control rats. DAT-KO rats more often demonstrated a fixed syntactic chain, making fewer errors and very rarely missing the chain steps in comparison to control rats. DAT-KO rats' behavior during inter-grooming intervals was completely different to the control animals. During learning and reversal learning in the T-maze, DAT-KO rats displayed pronounced patterns of hyperactivity and perseverative (stereotypical) activity, which led to worse learning and a worse performance of the task. Most of the DAT-KO rats could not properly learn the behavioral task in question. During re-learning, DAT-KO rats demonstrated rigid perseverative activity even in the absence of any reinforcement. In operant tasks, the mutant rats demonstrated poor extinction of operant lever pressing: they continued to perform lever presses despite no there being reinforcement. Our results suggest that abnormally elevated DA levels may be responsible for behavioral rigidity. It is conceivable that this phenomenon in DAT-KO rats reflects some of the behavioral traits observed in clinical conditions associated with endogenous or exogenous hyper-DA-ergia, such as schizophrenia, substance abuse, OCD, patients with Parkinson disease treated with DA mimetics, etc. Thus, DAT-KO rats may be a valuable behavioral model in the search for new pharmacological approaches to treat such illnesses.

Impulse Control Disorders in Southern Iraqi Patients Medicated With Cabergoline for Prolactinoma

BACKGROUND

Among the patient population in Basrah, Iraq, prolactinoma is the most commonly found pituitary tumor. Impulse control disorders (ICDs) were reportedly associated with these patients being treated with cabergoline. This study aimed to assess the prevalence of ICDs in cabergoline-treated prolactinoma patients versus healthy, matched controls.

METHODS

This cross-sectional case-control study was conducted at the Faiha Specialized Diabetes, Endocrine and Metabolism Center (FDEMC) in Basrah, southern Iraq, from January 2023 to May 2023. It included 30 cabergoline-treated prolactinoma patients and 30 healthy, matched controls. The questionnaire for ICDs in Parkinson's disease was used as a screening tool. Following this, positively screened patients were evaluated using validated criteria accordingly to diagnose impulse control disorders.

RESULTS

The ICDs were diagnosed in nine (30%) cabergoline-treated prolactinoma patients versus two (6.7%) in control (p = 0.02). The most frequent ICD types were hypersexuality and binge eating, while no patient reported pathological gambling. Three patients reported multiple types of ICDs. The patients' sociodemographic characteristics, prolactinoma duration and size, and cabergoline dose did not correlate significantly with ICD diagnosis.

CONCLUSIONS

Treatment with cabergoline is associated with the development of ICDs. Therefore, clinicians should be aware of this disabling side effect to ensure its early detection and treatment.

Disorders of impulsivity in trichotillomania and skin picking disorder

Trichotillomania and skin picking disorder are often classified as body-focused repetitive behaviors (BFRBs) as they are characterized by repetitive hair-pulling and skin picking, respectively. They were initially considered to be impulse control disorders despite little research scrutiny. The objective of this study was to examine the relationship of these two conditions to other disorders with impulsive features. Adults with trichotillomania (n = 104) and skin picking (n = 178) or both (n = 96) were recruited from the general community using advertisements and online support groups and completed an online survey. Participants undertook a structured clinical interview and completion of self-report instruments to characterize clinical profiles and associated characteristics. In addition, each participant completed the Minnesota Impulse Disorders Interview to screen for disorders with impulsive features. Of the 378 adults with BFRBs, 134 (35.4%) screened positive for at least one disorder with features of impulsivity with the most common being compulsive buying (18.3%) and problematic use of the internet (17.5%). Participants with a co-occurring disorder of impulsivity reported significantly worse pulling and picking symptoms (p < .001), were more likely to have co-occurring alcohol problems (p < .001) and PTSD (p < .001), and scored higher regarding dissociative symptoms (p < .001). BFRBs are associated with a range of impulsive disorders and the comorbidity may have important treatment implications.

Frequency of Impulsive-Compulsive Behavior and Associated Psychological Factors in Parkinson's Disease: Lack of Control or Too Much of It?

Background and Objectives: Impulse Control Disorders (ICDs) including pathological gambling, hypersexuality, compulsive eating, compulsive buying, and other related behaviors are well-known distinct non-motor symptoms in Parkinson's Disease (PD). Some large-scale studies present a prevalence of at least 10%, however, there are other reports providing much higher rates. The majority of the conducted studies investigating ICDs focus mainly on pharmacological factors, however, from a psychological perspective, there is yet enough room for investigation. In order to address the above issues, we designed a two-part study. Materials and Methods: First, we aimed to identify the incidence of ICD and related behaviors in a cohort of 892 Greek PD patients. Second, we administered a comprehensive battery of psychometric tools to assess psychological factors such as personality dimensions, quality of life, defenses, coherence, and resilience as well as to screen general cognitive capacity in PD patients with ICD manifestations. Results: With regard to the first part, we identified ICD manifestations in 12.4% of the patients. Preliminary findings from the second part indicate elevated activity, rather than impulsivity, as well as interrelations between several variables, including measures of activity, coping mechanisms, and quality of life. Conclusions: We present a working hypothesis for the contribution of high activity channeled to specific behavioral patterns through specific coping mechanisms, concerning the emergence of ICDs and related behaviors in PD, and further stress the importance of compulsivity rather than impulsivity in this process.

Acupuncture for Attenuating Frontal Lobe α Band Asymmetry Induced by Anger: a pilot study

Objectives

Previous studies have shown that anger can lead to frontal lobe α (8-13 Hz) band asymmetry (FAA) in electroencephalogram (EEG), in accordance with motivational direction. This pilot study aimed to investigate the impact of acupuncture on FAA elicited by anger.

Methods

Thirty-four right-handed participants scoring above 75 points on the Novaco Anger Scale were included. Baseline EEG signals were recorded for eight minutes using a 32-channel cap under comfortable conditions. Anger was induced through a nine-minute sequence of Articulated Thoughts in Simulated Situations (ATSS) task. Following that, participants received acupuncture at GB20 and GB21 for 10 minutes. Fast Fourier transform was employed for frequency analysis, and repeated measure ANOVA was conducted for statistical analysis.

Results

The results revealed that participants exhibited significantly higher FAA (p = 0.026), particularly in the left hemisphere, after the ATSS task sequence compared to the baseline. During acupuncture treatment, the greater left-sided FAA was significantly reduced (p = 0.027) and reversed. Upon the cessation of acupuncture, FAA returned to a value between the baseline and the anger-evoked stage (p = 0.046).

Conclusion

The EEG results of this study revealed that anger stimulation induced an increase in left-sided FAA, which was effectively alleviated by acupuncture. This led to an immediate restoration of FAA asymmetry induced by anger. These findings suggest the potential of acupuncture as a treatment option for reducing FAA associated with anger.

Impulse Control Disorders in the Polish Population of Patients with Parkinson's Disease

Background and Objectives: Parkinson's disease (PD) is one of the most common neurodegenerative diseases in the world. It is characterized by the presence of not only typical motor symptoms but also several less known and aware non-motor symptoms (NMS). The group of disorders included in the NMS is Impulse Control Disorders (ICDs). ICDs are a group of disorders in which patients are unable to resist temptations and feel a strong, pressing desire for specific activities such as gambling, hypersexuality, binge eating, and compulsive buying. The occurrence of ICDs is believed to be associated primarily with dopaminergic treatment, with the use of dopamine agonists (DA), and to a lesser extent with high doses of L-dopa. The aim of our study was to develop a profile of Polish ICDs patients and assess the frequency of occurrence of ICDs, as well as determine the risk factors associated with these disorders against the background of the PD population from other countries. Materials and Methods: Our prospective study included 135 patients with idiopathic PD who were hospitalized between 2020 and 2022 at the Neurological Department of University Central Hospital in Katowice. In the assessment of ICDs, we used the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP). Other scales with which we assessed patients with PD were as follows: MDS-UPDRS part III and modified Hoehn-Yahr staging. Clinical data on age, gender, disease duration and onset, motor complications, and medications were collected from electronic records. Results: ICDs were detected in 27.41% of PD patients (binge eating in 12.59%, hypersexuality in 11.11%, compulsive buying in 10.37%, and pathological gambling occurred in only 5.19% of patients. In total, 8.89% had two or more ICDs). The major finding was that ICDs were more common in patients taking DA than in those who did not use medication from this group (83.78% vs. 54.07%, respectively; p = 0.0015). Patients with ICDs had longer disease duration, the presence of motor complications, and sleep disorders. An important finding was also a very low detection of ICDs in a routine medical examination; only 13.51% of all patients with ICDs had a positive medical history of this disorder. Conclusions: ICDs are relatively common in the population of Polish PD patients. The risk factors for developing ICDs include longer duration of the disease, presence of motor complications, sleep disorders, and use of DA and L-dopa. Due to the low detectability of ICDs in routine medical history, it is essential for physicians to pay more attention to the possibility of the occurrence of these symptoms, especially in patients with several risk factors. Further prospective studies on a larger group of PD patients are needed to establish a full profile of Polish PD patients with ICDs.

["Impulsive insanity" according to Emil Kraepelin : A clinical framework for female criminals at the beginning of the twentieth century]

BACKGROUND

In his comprehensive classification of the beginning of the twentieth century, Emil Kraepelin provided a detailed description of an entity he called "impulsive insanity", which had not been elaborated before him. The forms depicted by him largely corresponded to the offences, which were referred to as typically female in their nature in the late nineteenth and early twentieth centuries.

QUESTION

How did Kraepelin classify "impulsive insanity" and what forms did he describe? Did Kraepelin also see these disorders predominantly prevailing in women, did he establish a connection with women's criminality and how did this fit into the discourses of the time on femininity, criminal legislation and degeneration?

MATERIAL AND METHODS

This study focused on the clinical picture "impulsive insanity" as described by Emil Kraepelin in his main work, the 8th edition of his Textbook of Psychiatry published between 1909 and 1915. His description was analyzed in detail and embedded in a historical context on the basis of secondary literature.

RESULTS

In rudiments Kraepelin's clinical classification is still comprehensible today, although there are major differences to how literature in later years treated this issue. Kraepelin clearly sees "impulsive insanity" as a driving disorder predominantly prevailing in women.

DISCUSSION

Elaborating his concept of "impulsive insanity", Kraepelin positioned himself in relation to important scientific discourses of the early twentieth century, such as the debate on criminal legislation and the theory of degeneration. On the basis of the individual forms of "impulsive insanity" described by Kraepelin, various concepts of constructing and pathologizing femininity can be identified. Apparently, it also aims to explain common female crimes within the patriarchal hegemony.

Excitatory SST neurons in the medial paralemniscal nucleus control repetitive self-grooming and encode reward

The use of body-focused repetitive behaviors (BFRBs) is conceptualized as a means of coping with stress. However, the neurological mechanism by which repetitive behaviors affect anxiety regulation is unclear. Here, we identify that the excitatory somatostatin-positive neurons in the medial paralemniscal nucleus (MPL^SST neurons) in mice promote self-grooming and encode reward. MPL^SST neurons display prominent grooming-related neuronal activity. Loss of function of MPL^SST neurons impairs both self-grooming and post-stress anxiety alleviation. Activation of MPL^SST neurons is rewarding and sufficient to drive reinforcement by activating dopamine (DA) neurons in the ventral tegmental area (VTA) and eliciting dopamine release. The neuropeptide SST facilitates the rewarding impact of MPL^SST neurons. MPL^SST neuron-mediated self-grooming is triggered by the input from the central amygdala (CeA). Our study reveals a dual role of CeA-MPL^SST-VTA^DA circuit in self-grooming and post-stress anxiety regulation and conceptualizes MPL^SST neurons as an interface linking the stress and reward systems in mice.

Impulse control disorders associated with dopaminergic drugs: A disproportionality analysis using vigibase

BACKGROUND

Dopamine receptor agonist drugs, which are used, for example, to treat Parkinson's disease (PD), increase the risk for impulse control disorders (ICDs), potentially resulting in devastating psychosocial consequences. It is unknown whether other drugs with dopaminergic properties also increase the risk for ICDs. This study assesses the disproportionality of reporting ICDs between drugs with dopaminergic properties and selected non-dopaminergic drugs.

METHODS

A case/non-case disproportionality analysis was performed, using data from VigiBase (1968-2020). Reports on ICDs as suspected adverse drug reactions (ADRs) were cases (n=852), and those with ADRs other than ICDs were non-cases (n=281,720). Relative reporting frequencies were expressed as adjusted reporting odds ratios (aRORs). Within the dopamine receptor agonists, the relationship between reporting odds ratios and dopamine receptor occupancy was explored.

RESULTS

A high disproportionality was found for reporting ICDs for all dopaminergic drugs (aROR 20.4 [95% CI 17.4-24.1]) compared to non-dopaminergic drugs. In pharmacotherapeutic subgroups, a high disproportionality was found for primary dopaminergic agents used in PD (aROR 52.1 [95% CI 44.1-61.5]), and to a lesser extent for ADHD psychostimulants and antidepressants (aROR 5.8 [95% 4.1-8.3] and aROR 3.9 [95% CI 2.9-5.6], respectively). There was no difference in reporting by consumers and healthcare professionals. The highest disproportionality was found for the dopamine receptor agonists pramipexole and ropinirole.

CONCLUSIONS

A signal of disproportion in ICD occurrence was found among all investigated drugs with dopaminergic properties, highlighting the importance of counselling and monitoring for ICDs when prescribing dopaminergic drugs.

Body-focused repetitive behaviors: Beyond bad habits

ABSTRACT

Body-focused repetitive behavior (BFRB) is a significantly underrecognized phenomenon that can cause physical complications and marked mental distress. Understanding the condition and offering patients pharmacologic as well as psychotherapeutic support may effectively reduce adverse health outcomes. This article reviews BFRBs, which can present clinically in multiple settings.

Prolactinomas

Hyperprolactinemia, defined by a level of serum prolactin above the standard upper limit of normal range, is a common finding in clinical practice and prolactinomas are the main pathological cause. Prolactinomas lead to signs and symptoms of hormone oversecretion, such as galactorrhea and hypogonadism, as well as symptoms of mass effect, including visual impairment, headaches and intracranial hypertension. Diagnosis involves prolactin measurement and sellar imaging, but several pitfalls are involved in this evaluation, which may difficult the proper management. Treatment is medical in the majority of cases, consisting of dopamine agonists, which present high response rates, with a very favorable safety profile. Major adverse effects that should be monitored consist of cardiac valvulopathy and impulse control disorders. Other treatment options include surgery and radiotherapy. Temozolomide may be used for aggressive or malignant carcinomas. Finally, pregnancy outcomes are similar to general population even when dopamine agonist treatment is maintained.

Increased prevalence of impulse control disorder symptoms in endocrine diseases treated with dopamine agonists: a cross-sectional study

INTRODUCTION

Impulse control disorders (ICDs) have been described as a side effect of dopamine agonists (DAs) in neurological as well as endocrine conditions. Few studies have evaluated the neuropsychological effect of DAs in hyperprolactinemic patients, and these have reported a relationship between DAs and ICDs. Our objective was to screen for ICD symptoms in individuals with DA-treated endocrine conditions.

MATERIALS AND METHODS

A cross-sectional analysis was conducted on 132 patients with pituitary disorders treated with DAs (DA exposed), as well as 58 patients with pituitary disorders and no history of DA exposure (non-DA exposed). Participants responded to the full version of the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's disease (QUIP).

RESULTS

Compared with the non-DA-exposed group, a higher prevalence of DA-exposed patients tested positive for symptoms of any ICD or related behavior (52% vs. 31%, p < 0.01), any ICD (46% vs. 24%, p < 0.01), any related behavior (31% vs. 17%, p < 0.05), compulsive sexual behavior (27% vs. 14%, p < 0.04), and punding (20% vs. 7%, p < 0.02) by QUIP. On univariate analysis, DA treatment was associated with a two- to threefold increased risk of any ICD or related behavior [odds ratio (OR) 2.43] and any ICD (OR 2.70). In a multivariate analysis, independent risk factors for any ICD or related behavior were DA use (adjusted OR 2.22) and age (adjusted OR 6.76). Male gender was predictive of the risk of hypersexuality (adjusted OR 3.82).

DISCUSSION

Despite the QUIP limitations, a clear sign of increased risk of ICDs emerges in individuals with DA-treated pituitary disorders. Our data contribute to the growing evidence of DA-induced ICDs in endocrine conditions.

The Prevalence of Impulse Control Disorders and Behavioral Addictions in Eating Disorders: A Systematic Review and Meta-Analysis

Aim: Individuals with eating disorders (EDs) may present with impulse control disorders (ICDs) and behavioral addictions (BAs), which may result in additional suffering and treatment resistance. However, the prevalence of ICDs and BAs in EDs has not been systematically examined. Therefore, this systematic review and meta-analysis aimed to assess the prevalence of ICDs and BAs in ED samples. Methods: A comprehensive electronic database search of the peer-reviewed literature was conducted in the following online databases: MEDLINE, PsycINFO, Embase, and CINAHL from their inception to May 2021. We restricted review eligibility to research studies reporting prevalence for ICDs or BAs in individuals with diagnosed EDs. The outcome for this review was the prevalence of ICDs or BAs in individuals with EDs. A series of random-effects meta-analyses were performed on eligible studies to estimate the pooled proportions and 95% confidence intervals (CIs). Results: Thirty-five studies met the inclusion criteria, including a total of 9,646 individuals identified as having an ED, 18 of these studies specifically examined ICDs/BAs in AN, BN, and BED. Random-effects pooled estimates demonstrated that the comorbid prevalence of any ICD was 22%. The prevalence of comorbid pathological/compulsive buying was highest (19%), followed by kleptomania (18%), pathological internet use (12%), intermittent explosive disorder (4%), trichotillomania (3%), and gambling disorder (2%). In addition, the prevalence of stealing/shoplifting behaviors was 30% in those with EDs. Conclusion: This is the first meta-analysis on the comorbid prevalence of EDs and ICDs/BAs. We found a moderate prevalence for these comorbid conditions, with approximately one out of five individuals with an ED also displaying a comorbid ICD/BA. Although causal inferences cannot be drawn, the numbers strongly suggest that clinical screening/monitoring of ICDs/BAs should be part of the clinical routine in cohorts with EDs. ED settings need either the capacity to manage these disorders or adequate access to relevant services. Further investigations are needed to reveal common underlying pathomechanisms. Systematic Review Registration: https://www.crd.york.ac.uk/prospero/, identifier: CRD42020202044.

Hypomania, Depression, Euthymia: New Evidence in Parkinson's Disease

The field related to mood disorders in Parkinson's disease (PD) is fragmented. The aim of this cohort observational study was to evaluate whether the episodes of mood alteration could appear in different disease stages and to verify how nonmotor symptoms were led off into different stages. We enrolled 93 PD outpatients (three groups: drug naive—DN; not exhibiting motor fluctuations—n-MF; and exhibiting motor fluctuations—MF) and 50 healthy controls. Mood state was assessed through the Internal State Scale (ISS) while depressive symptoms were evaluated through the Beck Depression Inventory-II (BDI-II), nonmotor symptoms by means of the Non-Motor Symptoms Scale (NMSS), and the presence of impulse control disorders (ICDs) with the Questionnaire for Impulsive-Compulsive Disorders in Parkinson's Disease (QUIP). Clinical and pharmacological data have also been recorded. No significant differences in mood state distribution between groups were observed. Nevertheless, as regards the mood state distribution within groups, in n-MF (47.6%) and MF patients (50%), (hypo)mania presence was significantly higher than other symptoms. In DN patients, hypomania showed a prevalence of 38.1% although it was not significant. At least one ICD was reported in 29.3% of n-MF and 50% of MF patients. In the MF group, a moderate positive correlation between ISS ACTivation subscale scores and the presence of ICDs and compulsive medication use emerged. Finally, MF patients reported higher BDI-II total scores than DN. Our results show that mood alterations in PD, considering both depressive symptoms and mood elevation, are related to the advanced stages of the disease as well as the presence of ICDs, and dopaminergic therapy would not always be able to restore a normal mood condition.

Zebrafish models of impulsivity and impulse control disorders

Impulse control disorders (ICDs) are characterized by generalized difficulty controlling emotions and behaviors. ICDs are a broad group of the central nervous system (CNS) disorders including conduct disorder, intermittent explosive, oppositional-defiant disorder, antisocial personality disorder, kleptomania, pyromania and other illnesses. Although they all share a common feature (aberrant impulsivity), their pathobiology is complex and poorly understood. There are also currently no ICD-specific therapies to treat these illnesses. Animal models are a valuable tool for studying ICD pathobiology and potential therapies. The zebrafish (Danio rerio) has become a useful model organism to study CNS disorders due to high genetic and physiological homology to mammals, and sensitivity to various pharmacological and genetic manipulations. Here, we summarize experimental models of impulsivity and ICD in zebrafish and highlight their growing translational significance. We also emphasize the need for further development of zebrafish ICD models to improve our understanding of their pathogenesis and to search for novel therapeutic treatments.

Impulsivity, Emotional Dysregulation and Executive Function Deficits Could Be Associated with Alcohol and Drug Abuse in Eating Disorders

Background: Empirical data suggests a high comorbid occurrence of eating disorders (EDs) and substance use disorders (SUDs), as well as neurological and psychological shared characteristics. However, no prior study has identified the neuropsychological features of this subgroup. This study examines the prevalence of alcohol and/or drug abuse (A/DA) symptoms in ED patients. It also compares the clinical features and neuropsychological performance of ED patients with and without A/DA symptoms. Methods: 145 participants (74.5% females) with various forms of diagnosed EDs underwent a comprehensive clinical (TCI-R, SCL-90-R and EDI-2) and neuropsychological assessment (Stroop, WCST and IGT). Results: Approximately 19% of ED patients (across ED subtypes) had A/DA symptoms. Those with A/DA symptoms showed more impulsive behaviours and higher levels of interoceptive awareness (EDI-2), somatisation (SCL-90-R) and novelty seeking (TCI-R). This group also had a lower score in the Stroop-words measure, made more perseverative errors in the WCST and showed a weaker learning trajectory in the IGT. Conclusions: ED patients with A/DA symptoms display a specific phenotype characterised by greater impulsive personality, emotional dysregulation and problems with executive control. Patients with these temperamental traits may be at high risk of developing a SUD.

Neuropsychiatric Aspects of Impulse Control Disorders

Impulse control disorders (ICDs) are neuropsychiatric conditions characterized by the repeated inability to resist an impulse, drive, or temptation to perform an act that is harmful to the person or others. Although classification approaches to ICDs vary both diachronically and synchronically, this group of conditions encompasses a wide range of syndromes, including pathologic gambling, kleptomania, trichotillomania, excoriation (skin picking) disorder, intermittent explosive disorder, pyromania, oppositional defiant, conduct, and antisocial personality disorders. ICDs can play a significant role as comorbidities in both neurodevelopmental (eg, attention-deficit/hyperactivity disorder, Tourette syndrome) and neurodegenerative (eg, Parkinson disease) disorders.

What drugs modify the risk of iatrogenic impulse-control disorders in Parkinson's disease? A preliminary pharmacoepidemiologic study

INTRODUCTION

Parkinson's disease (PD) patients treated with pramipexole (PPX) and ropinirole (ROP) exhibit a higher risk of developing impulse control disorders (ICDs), including gambling disorder, compulsive shopping, and hypersexuality. The management of ICDs in PD is challenging, due to the limited availability of effective therapeutic alternatives or counteractive strategies. Here, we used a pharmacoepidemiological approach to verify whether the risk for PPX/ROP-associated ICDs in PD patients was reduced by drugs that have been posited to exert therapeutic effects on idiopathic ICDs-including atypical antipsychotics (AAs), selective serotonin reuptake inhibitors (SSRIs), and glutamatergic modulators (GMs).

METHODS

To quantify the strength of the associations between PPX/ROP and other medications with respect to ICD risk, odds ratios (ORs) were calculated by multivariable logistic regression, adjusting for age, gender, marital status race, psychiatric comorbidities, and use of cabergoline and levodopa.

RESULTS

A total of 935 patients were included in the analysis. Use of GMs, SSRIs, and AAs was not associated with a decreased ICD risk in PD patients treated with PPX/ROP; conversely, ICD risk was significantly increased in patients treated with either GMs (Adjusted Odds Ratio, ORa: 14.00 [3.58-54.44]) or SSRIs (ORa: 3.67 [1.07-12.59]). Results were inconclusive for AAs, as available data were insufficient to compute a reliable ORa.

CONCLUSIONS

These results suggest that some of the key pharmacological strategies used to treat idiopathic ICD may not be effective for ICDs associated with PPX and ROP in PD patients. Future studies with larger cohorts are needed to confirm, validate, and extend these findings.

A Psycho-Behavioral Perspective on Modelling Obsessive-Compulsive Disorder (OCD) in Animals: The Role of Context

Obsessive-compulsive disorder is a heterogeneous and debilitating condition, characterized by intrusive thoughts and compulsive repetition. Animal models of OCD are important tools that have the potential to contribute significantly to our understanding of the condition. Although there is consensus that pre-clinical models are valuable in elucidating the underlying neurobiology in psychiatric disorders, the current paper attempts to prompt ideas on how interpretation of animal behavior can be expanded upon to more effectively converge with the human disorder. Successful outcomes in psychopharmacology involve rational design and synthesis of novel compounds and their testing in well-designed animal models. As part of a special journal issue on OCD, this paper will 1) review the psychobehavioral aspects of OCD that are of importance on how the above ideas can be articulated, 2) briefly elaborate on general issues that are important for the development of animal models of OCD, with a particular focus on the role and importance of context, 3) propose why translational progress may often be less than ideal, 4) highlight some of the significant contributions afforded by animal models to advance understanding, and 5) conclude by identifying novel behavioral constructs for future investigations that may contribute to the face, predictive and construct validity of OCD animal models. We base these targets on an integrative approach to face and construct validity, and note that the issue of treatment-resistance in the clinical context should receive attention in current animal models of OCD.

Thermal sensors improve wrist-worn position tracking

Wearable devices provide a means of tracking hand position in relation to the head, but have mostly relied on wrist-worn inertial measurement unit sensors and proximity sensors, which are inadequate for identifying specific locations. This limits their utility for accurate and precise monitoring of behaviors or providing feedback to guide behaviors. A potential clinical application is monitoring body-focused repetitive behaviors (BFRBs), recurrent, injurious behaviors directed toward the body, such as nail biting and hair pulling, which are often misdiagnosed and undertreated. Here, we demonstrate that including thermal sensors achieves higher accuracy in position tracking when compared against inertial measurement unit and proximity sensor data alone. Our Tingle device distinguished between behaviors from six locations on the head across 39 adult participants, with high AUROC values (best was back of the head: median (1.0), median absolute deviation (0.0); worst was on the cheek: median (0.93), median absolute deviation (0.09)). This study presents preliminary evidence of the advantage of including thermal sensors for position tracking and the Tingle wearable device’s potential use in a wide variety of settings, including BFRB diagnosis and management.

The Phenomenology of Lying in Young Adults and Relationships with Personality and Cognition

Despite research suggesting that lying may be a normal aspect of development and a fairly frequent occurrence in many adults, surprisingly little is known about its phenomenology and possible associations with relevant personality traits and cognitive functions. University students were invited to participate in an online study, which included a 91-item questionnaire and four neurocognitive tasks (selected to focus on frontal lobe function). The survey included questions about frequency of lying and reasons for doing so, mental health history, personality traits, religiosity, and insight into lying. Those who lied daily ("Daily Liars") were compared to those who lied less frequently ("Non-Daily Liars"). 18.1% of the sample reported lying every day. Daily Liars showed worse grade point averages, quality of life, and self-esteem. Daily Lying was associated with negative functional impact on school, social, and family/home domains. We did not find evidence that is was associated with frontal lobe dysfunction on the cognitive tasks examined.

Compulsive eating behaviors in Parkinson's disease

PURPOSE

Eating disorders are common in Parkinson's disease (PD) patients and often class in Impulse control disorders, however, little is known about their phenomenology. Specific symptoms and comorbidities were described in a group of PD patients in this preliminary study.

METHODS

Over a period of 6 months, 51 PD patients who experienced significant changes in eating habits following diagnosis of PD and were interviewed during regularly scheduled follow-up visits. We assessed each patient's height and weight, impulsivity, psychological distress, current eating disorder symptoms, food addiction, food habits and craving.

RESULTS

Among the PD patients who experienced modified dietary habits following diagnosis, few exhibited binge eating disorders (BED) full criteria (3.9%). However, 21.6% of patients experienced episodes of out-of-control eating with a large quantity of food in short time and 39.2% satisfied food addiction (FA) criteria without binge eating disorder. Food cravings more than once a week were experienced in approximately half of the population including all FA patients. Regarding comorbidities, FA PD patients present impulsive features and anxiety.

CONCLUSIONS

This study confirms the existence of FA profile in PD patients. Eating disorders even in PD are complex and have a cross-cutting criteria related to out-of-control eating, FA, and BED. The association of anxiety with PD-related food addiction, contrary to L-dopa equivalent daily dose mean score or the presence of dopamine agonists, underline the complex sustainability of the dopaminergic brainstem support. A study on their detailed prevalence in this population could be helpful to better understand unspecified feeding or eating disorder.

CLINICAL TRIAL NUMBER

DR-2012-007.

NAME OF THE REGISTRY

French Committee for the Protection of Persons (CPP) & French National Commission on Computing and Liberty (CNIL).

LEVEL OF EVIDENCE

Level V, descriptive study.

Naltrexone Acutely Enhances Connectivity Between the Ventromedial Prefrontal Cortex and a Left Frontoparietal Network

BACKGROUND

Naltrexone, an opioid receptor antagonist that is Food and Drug Administration approved for treating alcohol use disorder (AUD), reduces alcohol craving and intake. Despite known pharmacological properties, little is known regarding the effects of naltrexone on neural circuit function. Thus, a data-driven examination of the neural effects of naltrexone in human subjects may offer novel insight into its treatment mechanisms.

METHODS

Twenty-one alcohol using males (22 to 39) participated in a double-blind, placebo-controlled crossover study of the effects of naltrexone on brain voxel-wise functional connectivity (FC) using intersubject FC correlation mapping. We first cross-correlated the time series from each gray matter voxel to produce a 6,356 × 6,356 FC matrix for each subject and session. We then subtracted the placebo FC matrix from the naltrexone FC matrix. To identify brain regions demonstrating significant reconfiguration of whole-brain FC patterns following naltrexone treatment, we statistically quantified the consistency of patterns of voxel FC changes across subjects. Permutation testing identified significant clusters of voxels undergoing significant reconfiguration. Using the identified clusters in a seed-based FC analysis, we then compared the FC patterns of affected brain areas on placebo versus naltrexone in a paired t-test. Ridge regression analyses identified self-report measures, including substance use, that significantly predicted individual differences in FC among naltrexone-modulated regions.

RESULTS

Two clusters in the rostral anterior cingulate cortex (rACC)/ventromedial prefrontal cortex (vmPFC) demonstrated significant modulation of FC by naltrexone. Using these 2 proximal clusters as a single seed, specific FC changes were identified in regions associated with a left frontoparietal network (increasing), as well as visual and motor regions (decreasing). Stronger FC between the rACC/vmPFC and this set of regions on placebo was associated with more external locus of control, whereas weaker connectivity was associated with greater substance use problems. Naltrexone strengthened these connections most among individuals who reported greater drinking to cope.

CONCLUSIONS

Enhancing connectivity between the rACC/vmPFC, implicated in alcohol craving, and components of a left frontoparietal network involved in executive control may represent an effective strategy for the treatment of AUD.

Current treatment of behavioral and cognitive symptoms of Parkinson's disease

Cognitive and behavioral symptoms are common in Parkinson's disease, may occur even in the prodromal stages of the disease, worsen with disease progression, and surpass motor symptoms as the major factors affecting patient quality of life and caregiver burden. The symptoms may be caused by the disease pathology or they may represent adverse effects of treatment, or both etiological factors may contribute. Although many of these symptoms are related to dopaminergic dysfunction or dopaminergic medication, other neurotransmitters are involved as well. Behavioral symptoms including impulse control disorders, apathy, psychosis, as well as mild cognitive impairment and dementia are reviewed with a special focus on current treatment approaches.

Integrated treatment program for alcohol related problems in community hospitals, Songkhla province of Thailand: A social return on investment analysis

OBJECTIVES

To estimate the impacts and social value relative to the cost of the Integrated Management of Alcohol Intervention Program in the Health Care System (i-MAP) on direct beneficiaries, using a Social Return on Investment (SROI) analysis.

METHOD

A mixed-method approach was conducted among stakeholders and 113 drinkers (29 low-risk, 43 high-risk, and 41 dependent drinkers) who consecutively received i-MAP at four community hospitals in Songkhla province of Thailand. Resources for program implementation as well as drinking and a list of psychosocial outcomes, selected through stakeholder interviews, were measured among participants during and at the sixth month after participation, respectively. SROI (societal benefit-to-cost) ratio of i-MAP was estimated over a 5-year time horizon and shown in 2017 Thai baht, where US$1.00 = 33.1 baht. One-way and probabilistic sensitivity analyses of key parameters were performed among treatment subgroups.

RESULTS

Baseline estimates of the annual cost and 5-year social value of i-MAP were 25.5 and 51.0 million baht, respectively, yielding an estimated SROI ratio of 2.0, with a possible range of 1.3 to 2.4. Value created by the program was mostly attributed to broader gains to society (productivity gains and averted crime costs) and drinkers. Subgroup analyses suggested that the SROI ratio for high-risk drinkers was twice that for dependent drinkers (2.8 vs. 1.5). The probabilistic sensitivity analysis showed that more than 99% of the simulated treatments for both high-risk and dependent groups yielded benefits beyond the corresponding costs.

CONCLUSIONS

By considering societal perspective, the i-MAP program has demonstrated its social value is twice its investment cost and potential for the program to be implemented nationwide.

Interaction Between Neuropsychiatric Symptoms and Cognitive Performance in Parkinson's Disease: What Do Clinical and Neuroimaging Studies Tell Us?

PURPOSE OF REVIEW

Parkinson's disease was studied for a long time from the prism of a motor impairment. Recent advances have outlined the importance of cognitive and neuropsychiatric symptoms (NPS) in the PD equation. This review concentrates on the present possibilities of using neuroimaging techniques in order to quantify the cognitive performance and NPS in PD patients.

RECENT FINDINGS

Mild cognitive impairment as well as many NPS have been acknowledged as important criteria for assessing the quality of life in patients with Parkinson's disease and have been shown as potential factors in predicting further evolution of PD from a clinical perspective. Some NPS strongly influence cognition (depression, REM sleep behavior disorder), while others are less specifically associated with it (impulse control disorders). Neuroimaging techniques reported specific structural, functional, and metabolic brain changes that might be specific for each NPS type. Recent neuroimaging advances report a strong interrelation between NPS and cognitive performance in PD. A special place for consideration is given to REM sleep behavior disorder, depression, and hallucinations. Nevertheless, some studies report distinct results, outlining that the neuroimaging acquisition and analysis techniques still have limitations and also likely represent the complexity of the manifestation of NPS in PD.

Impulse control and related disorders in Parkinson's disease

Neuropsychiatric disorders are common among patients with Parkinson's disease and may appear in any stage of the disease. However, these disorders often go undiagnosed and receive insufficient treatment. Observations in recent years have revealed that dopamine replacement therapy may lead to the development or worsening of conditions, such as gambling disorder, compulsive sexual behavior, compulsive buying and binge eating, in addition to punding and dopamine dysregulation syndrome. The pathophysiology of these disorders seems to be related to abnormal dopaminergic stimulation of the basal regions of the basal ganglia, especially via nigro-mesolimbic pathways. The aim of the present study was to perform a literature review on impulsivity, impulse control disorders and related conditions among patients with Parkinson's disease, with emphasis on their epidemiology, clinical characteristics and treatment.

Sleep in Parkinson's Disease with Impulse Control Disorder

PURPOSE OF REVIEW

This paper aims to explore the relationship between impulse-control disorders (ICDs) and sleep problems in patients with Parkinson's disease (PD) among scientific literature.

RECENT FINDINGS

Previously published results are controversial and sometimes inconclusive. ICDs and sleep disruption represent important non-motor features of Parkinson's disease, responsible for reducing quality of life and increasing burden of disease. The relationship between sleep problems and ICDs is complex and bidirectional. Indeed, sleep disturbances and fragmentation may play a crucial role in increasing susceptibility to impulsive behavior and may represent a risk factor for developing ICDs in PD patients. Moreover, REM sleep behavior disorder (RBD) and restless legs syndrome (RLS) have been indicated as independent risk factors for ICDs in PD patients. On the other hand, also ICDs may lead to sleep restriction and fragmentation, suggesting a bidirectional relationship. The association between sleep problems and ICDs in PD is far from being completely understood. Further studies are needed to confirm the nature of this relationship and its pathophysiology.

Sleep and REM sleep behaviour disorder in Parkinson's disease with impulse control disorder

INTRODUCTION

Because the association between rapid eye movement sleep behaviour disorder (RBD) and impulse control disorders (ICDs) in Parkinson's disease (PD) has been debated, we assessed the sleep characteristics and the frequency of RBD using video-polysomnography (v-PSG) in patients with PD with versus without ICDs.

METHODS

Eighty non-demented patients with PD consecutively identified during routine evaluation at three movement disorders centres were enrolled in a case-control study. Forty patients (22 men; mean age: 62.6±9.7 years, Hoehn & Yahr: 2.1±0.6) with one or more current ICDs were age-matched and sex-matched with 40 patients with no history of ICDs (22 men, mean age: 64.9±7.8 years, Hoehn & Yahr: 2.2±0.6). They underwent a detailed sleep interview followed by a full-night in-lab v-PSG. Sleep was scored blindly to ICDs condition and RBD diagnosis included a clinical complaint of enacted dreams and/or documented behaviour during rapid eye movement (REM) sleep, with the presence of quantified REM sleep without atonia (RSWA).

RESULTS

Patients with ICDs had a higher arousal index and higher RSWA than those without ICDs (51.9%±28.2%vs 32.2±27.1%, p=0.004). In addition, RBD was more frequent in the ICD group (85%vs53%, p=0.0001). RBD was still associated with ICDs in a multivariate regression analysis including age of onset, PD duration and severity, treatment duration, levodopa-equivalent and dopamine agonist-equivalent daily doses and antidepressant use (OR: 4.9 (95% CI 1.3 to 18.5), p=0.02).

CONCLUSIONS

This large, controlled series of patients with PD with ICDs assessed by v-PSG confirms the association between ICDs and RBD. Increased surveillance of symptoms of ICDs should be recommended in patients with PD with RBD.

Presidential Address: Are the Obsessive-Compulsive Related Disorders Related to Obsessive-Compulsive Disorder? A Critical Look at DSM-5's New Category

The 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM) includes a new class of obsessive-compulsive and related disorders (OCRDs) that includes obsessive-compulsive disorder (OCD) and a handful of other putatively related conditions. Although this new category promises to raise awareness of underrecognized and understudied problems, the empirical validity and practical utility of this new DSM category is questionable. This article critically examines the arguments underlying the new OCRD class, illuminates a number of problems with this class, and then discusses implications for clinicians and researchers.

Impulse control disorder and response-inhibition alterations in Parkinson's disease. A rare case of totally absent functionality of the medial-prefrontal cortex and review of literature

This report illustrates a Parkinson’s disease (PD) patient with impulse-control disorder (ICD) and selective impairment in response-inhibition abilities as revealed by the performance in a functional magnetic resonance imaging (fMRI) anterior cingulate cortex - sensitive go-nogo task. In line with hypothesis on the role of response-inhibition disabilities in the arising of impulsivity in PD, the patient completely failed the go-nogo task. Moreover, fMRI acquisition revealed absent task-sensitive activity in the anterior cingulate cortex, medial prefrontal, and orbitofrontal cortices for the contrast nogo versus go, which signifying that a hypo-function of this network could be associated with ICD. A fronto-striatal and cingulo-frontal dysfunction may reflect impairment in metacognitive-executive abilities (such as response-inhibition, action monitoring, and error awareness) and promote compulsive repetition of behavior. Response-inhibition tasks may be useful in PD post-diagnostic phase, to better identify individuals at risk of developing ICD with dopaminergic medication.

Harms associated with taking nalmefene for substance use and impulse control disorders: A systematic review and meta-analysis of randomised controlled trials

Importance

Nalmefene is a newly approved drug for alcohol use disorder, but the risk of harms has not been evaluated from empirical trial evidence.

Objective

To assess the harm of nalmefene administered to individuals diagnosed with substance use or impulse control disorders by performing a systematic review and meta-analysis of randomised controlled trials.

Data sources

A search was performed in Cochrane Central Register of Controlled Trials (CENTRAL, 2014), MEDLINE via PubMed (1950), EMBASE via Ovid (1974), and Clinicaltrials.gov through December 2014.

Study selection

This study included only randomised controlled trials with placebo or active controls that administered nalmefene to adult individuals for treating impulse control and/or substance use disorders. Both published and unpublished randomised controlled trials were eligible for inclusion.

Data extraction and synthesis

Internal validity was assessed using the Cochrane risk-of-bias tool. Published information from the trials was supplemented by contact between reviewers and industry sponsor. Data were combined using two meta-approaches in fixed effects models; Peto Odds Ratios and risk differences were reported with 95% confidence intervals (95%CIs).

Main outcomes and measures

Number of patients with serious adverse events, including specific psychiatric serious adverse events and withdrawals due to adverse events.

Results

Of 20 potentially relevant studies, 15 randomised controlled trials met the inclusion criteria, and 8 of these provided data enabling the meta-analysis. Overall, serious adverse events did not occur more often in the nalmefene group than in the placebo group (Peto Odds Ratio = 0.97 [95% CI 0.64–1.44]; P = 0.86). Risk of psychiatric serious adverse events was slightly elevated, albeit not at a statistically significant level (Peto Odds Ratio = 1.32 [95% CI 0.62, 2.83]; P = 0.47). Withdrawals due to adverse events were significantly more likely to occur with nalmefene compared to placebo (Peto Odds Ratio = 3.22 [95% CI 2.46–4.22]; P<0.001)

Conclusions and relevance

The three-fold increased risk of withdrawal from treatment on nalmefene due to adverse events is a matter of safety concern. The nature of these adverse events cannot be elucidated further without access to individual patients data.

A multispecies approach for understanding neuroimmune mechanisms of stress

The relationship between stress challenges and adverse health outcomes, particularly for the development of affective disorders, is now well established. The highly conserved neuroimmune mechanisms through which responses to stressors are transcribed into effects on males and females have recently garnered much attention from researchers and clinicians alike. The use of animal models, from mice to guinea pigs to primates, has greatly increased our understanding of these mechanisms on the molecular, cellular, and behavioral levels, and research in humans has identified particular brain regions and connections of interest, as well as associations between stress-induced inflammation and psychiatric disorders. This review brings together findings from multiple species in order to better understand how the mechanisms of the neuroimmune response to stress contribute to stress-related psychopathologies, such as major depressive disorder, schizophrenia, and bipolar disorder.

Management of impulse control disorders in Parkinson's disease

BACKGROUND

Impulse control disorders (ICDs) have become a widely recognized non-motor complication of Parkinson's disease (PD) in patients taking dopamine replacement therapy (DRT). There are no current evidence-based recommendations for their treatment, other than reducing their dopaminergic medication.

METHODS

This study reviews the current literature of the treatment of ICDs including pharmacological treatments, deep brain stimulation, and psychotherapeutic interventions.

RESULTS

Dopamine agonist withdrawal is the most common and effective treatment, but may lead to an aversive withdrawal syndrome or motor symptom degeneration in some individuals. There is insufficient evidence for all other pharmacological treatments in treating ICDs in PD, including amantadine, serotonin selective reuptake inhibitors, antipsychotics, anticonvulsants, and opioid antagonists (e.g. naltrexone). Large randomized control trials need to be performed before these drugs can be routinely used for the treatment of ICDs in PD. Deep brain stimulation remains equivocal because ICD symptoms resolve in some patients after surgery but may appear de novo in others. Cognitive behavioral therapy has been shown to improve ICD symptoms in the only published study, although further research is urgently needed.

CONCLUSIONS

Further research will allow for the development of evidence-based guidelines for the management of ICDs in PD.

Repetitive urges to inflict burns: An unusual presentation of impulse control disorder

Impulse control disorders (ICDs) are characterized by an inability to resist an intense impulse or drive to perform a particular act that is excessive and/or harmful to self/others. Till date, there is no published report of an ICD presenting with repetitive urges to inflict burns. We describe the case of an adult male in regular follow-up for 6 months who presented with intense, irresistible, and repetitive urges and acts of causing burns on his skin for past 1 year. The phenomenology shared the core qualities described for ICDs and patient showed adequate response to treatment. The case report describes an unusual type of ICD classifiable as not otherwise specified. More clinical and research attention is warranted toward ICDs in general, with implications for ICD-11.

Meta-cognitions in tourette syndrome, tic disorders, and body-focused repetitive disorder

OBJECTIVE

To explore if self-reported presence of thinking about tics or body-focused repetitive behaviours (BFRBs; gests) are direct triggers of tic or gest onset in 3 groups: Tourette syndrome (TS; n =18), persistent chronic tic disorders (TDs; n = 42), and a comparison group with BFRB (n = 36).

METHOD

The 3 groups completed a thinking about tics inventory, listing 22 items derived from clinician consensus that asked whether thoughts always, sometimes, or never exclusively triggered tic onset. Other questionnaires measured mood, perfectionism, impulsivity, premonitory urge, and self-rated tension. Sixty-three participants completed the inventory twice, and the inventory was completed pre- and post-behavioural intervention by a further 54.

RESULTS

The ranking of the thoughts reported as likely to trigger tics or gests was positively correlated across TD and BFRB groups. Exploratory principal components analysis of a reduced 12-item set (the thinking about tics inventory) in TS and TD groups revealed that such thoughts could be grouped into 3 separate subscales: thoughts about the interference of tics or gests, thoughts anticipating tics or gests, and thoughts about whether the person has permission to perform the tic or the gest. The 3 sets of subscales showed good and acceptable internal consistency and overall score showed good test-retest reliability, suggesting thoughts about tics or gests are robust and measurable. The subscales correlated with impulsivity, tic or behaviour severity, and ratings of frequency decreased post-behavioural treatment.

CONCLUSIONS

Thinking about tics or gests is reported as triggering tics or gests in both TD and BFRB, and meta-cognition seems independent of premonitory sensations and relates to distinct clinical characteristics in each clinical group.

Impulse control disorders in Parkinson's disease: an overview from neurobiology to treatment

Parkinson's disease (PD) is the second most common neurodegenerative brain disorder and is characterized by motor symptoms such as tremor, bradykinesia, rigidity and postural instability. A majority of the patients also develop non-motor symptoms. Impulse control disorders (ICD) are behavioural changes that often fail to be detected in clinical practice. The prevalence of ICD in PD varies widely from 6.1 to 31.2 % and treatment with dopaminergic medication is considered to be the greatest risk factor. Management consists mainly of reducing dopaminergic medication. In our experience, ICD has a tremendous impact on the quality of life of the patients and their families and should therefore not be disregarded. Studies addressing the role of ICD in PD caregiver strain are imperative. We attempt to give a comprehensive overview of the literature on the complicated neurobiology of ICD and discuss risk factors, genetic susceptibility, screening modalities and management.

Pathological generosity: an atypical impulse control disorder after a left subcortical stroke

Changes in socio-emotional behavior and conduct, which are characteristic symptoms of frontal lobe damage, have less often been described in patients with focal subcortical injuries. We report on a case of pathological generosity secondary to a left lenticulocapsular stroke with hypoperfusion of several anatomically intact cortical areas. A 49-year-old man developed excessive and persistent generosity as he recovered from a left lenticulocapsular hematoma. His symptoms resembled an impulse control disorder. (99m)Tc-HMPAO SPECT demonstrated hypoperfusion mostly in the ipsilateral striatum, dorsolateral, and orbitofrontal cortex. This case study adds pathological generosity to the range of behavioral changes that may result from discrete unilateral lesions of the lenticular nucleus and nearby pathways. In our particular case, post-stroke pathological generosity was not ascribable to disinhibition, apathy, mania, or depression. Because pathological generosity may lead to significant distress and financial burden upon patients and their families, it may warrant further consideration as a potential type of impulse control disorder.

Dopaminergic and clinical correlates of pathological gambling in Parkinson's disease: a case report

Dopaminergic medication for motor symptoms in Parkinson's disease (PD) recently has been linked with impulse control disorders, including pathological gambling (PG), which affects up to 8% of patients. PG often is considered a behavioral addiction associated with disinhibition, risky decision-making, and altered striatal dopaminergic neurotransmission. Using [(11)C]raclopride with positron emission tomography, we assessed dopaminergic neurotransmission during Iowa Gambling Task performance. Here we present data from a single patient with PD and concomitant PG. We noted a marked decrease in [(11)C]raclopride binding in the left ventral striatum upon gambling, indicating a gambling-induced dopamine release. The results imply that PG in PD is associated with a high dose of dopaminergic medication, pronounced motor symptomatology, young age at disease onset, high propensity for sensation seeking, and risky decision-making. Overall, the findings are consistent with the hypothesis of medication-related PG in PD and underscore the importance of taking clinical variables, such as age and personality, into account when patients with PD are medicated, to reduce the risk of PG.

Is premature ejaculation an impulse control disorder?

Premature ejaculation (PE) is defined as persistent or recurrent ejaculation with minimal sexual stimulation that occurs before the participant wishes to ejaculate and is associated with marked distress or interpersonal difficulty. Impulse control disorders (ICDs) are grouped as a heterogeneous cluster of disorders linked by a "failure to resist" impulses to engage in harmful, disturbing or distressing behaviours. I hypothesise that premature ejaculation is an impulse control disorder. ICDs share features with PE aspects of impaired control, rapid responses to stimuli and hypersensitivity. These disorders often occur with subjective and social distress for patients. In addition to these features, the neurotransmitter systems have been similarly implicated in ICDs and PE. The same treatment options further support a relationship between ICDs and PE. The behaviours likely exist on a spectrum.