Interacting mechanisms of impulsivity in bipolar disorder and antisocial personality disorder

Abstract

Background Bipolar disorder and antisocial personality disorder (ASPD) overlap in clinical characteristics and behavioral consequences. Impulsivity is prominent in both, but there is little information on how specific mechanisms of impulsivity differentiate, bridge, or underlie the disorders. Methods Subjects, all males, were controls (n=46), bipolar disorder without cluster B personality disorder (n=21), ASPD without bipolar disorder (n=50), and bipolar disorder with ASPD (n=16). Impulsivity measures were the Immediate Memory Task (IMT), a continuous performance test of response inhibition measuring ability to evaluate a stimulus before responding, and the Two Choice Impulsivity Paradigm (TCIP), a choice between smaller-sooner and larger-later reward. Data were analyzed using general linear models analysis. Results Subjects with bipolar disorder had fewer IMT correct detections and slower reaction times than controls. Reaction times were faster with combined diagnoses than in bipolar disorder alone. TCIP responding in either diagnosis alone resembled controls, but was more impulsive in combined disorders. These differences persisted after correction for age and education, which had significant independent effects. In combined ASPD and bipolar disorder, increased reaction speed, impulsive response bias, and reward-delay impulsivity occurred independent of substance-use disorder history. Conclusions Impulsivity was increased in the combined disorders over either disorder alone. Results were consistent with at least partially distinct mechanisms of impulsivity in ASPD and bipolar disorder. Compensatory mechanisms for impulsivity in uncomplicated ASPD or bipolar disorder appear to be compromised or lost when the disorders are combined.

A Proof-of-Mechanism Study to Test Effects of the NMDA Receptor Antagonist Lanicemine on Behavioral Sensitization in Individuals With Symptoms of PTSD

“…Behavioral sensitization refers to a process whereby traumaassociated stress (but also repeated use of substances of abuse, mood or anxiety episodes, and suicide attempts) sensitize behavioral, motivational and stress systems, thereby increasing the behavioral and physiological reactivity to subsequent stressors or other sensitizing agents even after a prolonged absence of those agents (15)(16)(17)(18). Consistent with findings in animals, research in humans showed at least three different aspects of behavioral sensitization: induction, the development of behavioral sensitization to a sensitizing agent, including uncontrollable stressors (19), substances of abuse (18,20,21), and, in PTSD, repeated illness episodes (22); expression, exaggerated behavioral or physiological responses to a sensitizing agent even after prolonged absence of that agent (18,21,23); and cross-sensitization, the process by which sensitization to one agent results in sensitization to other agents (e.g., facilitation of behavioral sensitization to psychostimulants after exposure to uncontrollable stress) (24). Animal research showed that all three aspects of behavioral sensitization require activation of NMDARs albeit via different neural pathways.…”

“…An important difference between lanicemine and ketamine concerns dissociative side effects. Although 8% of patients with treatment resistant depression in the lanicemine 100 mg arm spontaneously reported dissociative symptoms compared to 4% in both the lanicemine 50 mg and placebo arms, only 1.1% of patients in both lanicemine groups had a Clinician-Administered Dissociative States Scale (CADSS) score classified as high (11)(12)(13)(14)(15)(16)(17)(18)(19)(20)(21)(22)(23)(24)(25) at any time point. In contrast, 50% of patients with treatment resistant depression showed high dissociation with a 40 minute subanesthetic infusion of ketamine (73).…”

The role of cortisol and psychopathy in the cycle of violence

“…Similarly, the lack of a relationship between impulsivity and aggression could be a result of the tool used to measure impulsivity (i.e., BIS-11). A recent study examining the impulsivity in a group diagnosed with antisocial personality disorder similarly reported no significant relationship between BIS-11 and aggression but did find a relationship between aggression and behavioral tasks that measured impulsivity (Swann et al 2011). As Swann et al (2011) reported that inconsistencies between the relationship between impulsivity and aggression may depend on the type of measurement used (e.g., psychometric or behavioral), it is plausible that each measurement only captures a portion of the variability in the underlying impulsiveness in the sample.…”

Patterns of Mood and Personality Factors and Associations With STI/HIV-Related Drug and Sex Risk Among African American Male Inmates

“…Impulsivity is featured in both antisocial and BPDs, and co-occurring ASPD and BPD may exhibit profiles of impulsivity specific to each disorder that impact STI/HIV-related risk. Research suggests that the symptoms of mental disorders, including ASPD and BPD, are differentially related to impulsivity (Swann, Lijffijt, Lane, Steinberg, & Moeller, 2013) and that the mechanisms underlying impulsivity vary across disorders (Swann, Lijffijt, Lane, Steinberg, & Moeller, 2011). Beyond impulsivity alone, the combination of features of BPD, such as emotional dysregulation may result in elevated sexual risk-taking (Malow et al, 2007; Messman-Moore, Walsh, & DiLillo, 2010).…”