Impulsivity in patients with borderline personality disorder: a comprehensive profile compared with healthy people and patients with ADHD.

BACKGROUND: Impulsivity is a core symptom of borderline personality disorder (BPD). Impulsivity is a heterogeneous concept, and a comprehensive evaluation of impulsivity dimensions is lacking in the literature. Moreover, it is unclear whether BPD patients manifest impaired cognitive functioning that might be associated with impulsivity in another patient group, such as ADHD, a frequent comorbidity of BPD. METHODS: We tested 39 patients with BPD without major psychiatric comorbidities and ADHD, 25 patients with ADHD, and 55 healthy controls (HC) using a test battery consisting of a self-report measure of impulsivity (UPPS-P questionnaire), behavioral measures of impulsivity - impulsive action (Go/NoGo task, stop signal task) and impulsive choice (delay discounting task, Iowa gambling task), and standardized measures of attention (d2 test), working memory (digit span), and executive functioning (Tower of London). RESULTS: Patients with BPD and ADHD, as compared with HC, manifested increased self-reported impulsivity except sensation seeking and increased impulsive choice; patients with ADHD but not BPD showed increased impulsive action and deficits in cognitive functioning. Negative urgency was increased in BPD as compared to both HC and ADHD groups and correlated with BPD severity. CONCLUSIONS: Patients with BPD without ADHD comorbidity had increased self-reported impulsivity and impulsive choice, but intact impulsive action and cognitive functioning. Controlling for ADHD comorbidity in BPD samples is necessary. Negative urgency is the most diagnostically specific impulsivity dimension in BPD.

Behavioral and Neuroanatomical Account of Impulsivity in Parkinson's Disease.

Impulse control disorder (ICD) is a major non-motor complication of Parkinson's disease (PD) with often devastating consequences for patients' quality of life. In this study, we aimed to characterize the phenotype of impulsivity in PD and its neuroanatomical correlates. Methods: Thirty-seven PD patients (15 patients with ICD, 22 patients without ICD) and 36 healthy controls underwent a neuropsychological battery. The test battery consisted of anxiety and depression scales, self-report measures of impulsivity (Barratt scale and UPPS-P), behavioral measures of impulsive action (Go/No-Go task, Stop signal task) and impulsive choice (Delay discounting, Iowa gambling task), and measures of cognitive abilities (working memory, attention, executive function). Patients and controls underwent structural MRI scanning. Results: Patients with ICD had significantly higher levels of self-reported impulsivity (Barratt scale and Lack of perseverance from UPPS-P) in comparison with healthy controls and non-impulsive PD patients, but they performed similarly in behavioral tasks, except for the Iowa gambling task. In this task, patients with ICD made significantly less risky decisions than patients without ICD and healthy controls. Patients without ICD did not differ from healthy controls in self-reported impulsivity or behavioral measurements. Both patient groups were more anxious and depressive than healthy controls. MRI scanning revealed structural differences in cortical areas related to impulse control in both patient groups. Patients without ICD had lower volumes and cortical thickness of bilateral inferior frontal gyrus. Patients with ICD had higher volumes of right caudal anterior cingulate and rostral middle frontal cortex. Conclusions: Despite the presence of ICD as confirmed by both clinical follow-up and self-reported impulsivity scales and supported by structural differences in various neural nodes related to inhibitory control and reward processing, patients with ICD performed no worse than healthy controls in various behavioral tasks previously hypothesized as robust impulsivity measures. These results call for caution against impetuous interpretation of behavioral tests, since various factors may and will influence the ultimate outcomes, be it the lack of sensitivity in specific, limited ICD subtypes, excessive caution of ICD patients during testing due to previous negative experience rendering simplistic tasks insufficient, or other, as of now unknown aspects, calling for further research.

Disruption of Multiple Distinctive Neural Networks Associated With Impulse Control Disorder in Parkinson's Disease.

The phenomenon of impulsivity in Parkinson's disease appears as an arduous side effect of dopaminergic therapy with potentially detrimental consequences for the life of the patients. Although conceptualized as a result of non-physiologic chronic dopaminergic stimulation, recent advances speculate on combined disruption of other networks as well. In the search for neuroanatomical correlates of this multifaceted disturbance, this study employs two distinct, well-defined tasks of close association to motor inhibition and decision-making impulsivity, Go/No Go and Delay discounting. The fMRI and functional connectivity analysis in 21 Parkinson's disease patients, including 8 patients suffering from severe impulse control disorder, and 28 healthy controls, revealed in impulsive Parkinson's disease patients not only decreased fMRI activation in the dorsolateral prefrontal cortex and bilateral striatum, but also vast functional connectivity changes of both caudate nuclei as decreased connectivity to the superior parietal cortex and increased connectivity to the insular area, clearly beyond the commonly stated areas, which indicates that orbitofronto-striatal and mesolimbic functional disruptions are not the sole mechanisms underlying impulse control disorder in Parkinson's disease. Ergo, our results present a refinement and synthesis of gradually developing ideas about the nature of impulsive control disorder in Parkinson's disease-an umbrella term encompassing various behavioral deviations related to distinct neuronal networks and presumably neurotransmitter systems, which greatly exceed the previously envisioned dopaminergic pathways as the only culprit.