Bipolar disorders, which encompasses primarily bipolar I and II disorders, are a subcategory of mood disorders that is characterized by episodes of mania and depression causing dysfunction. A diagnosis of bipolar II disorder requires at least one depressive episode and a hypomanic episode whereas a diagnosis of bipolar I requires only a manic episode (1, 2), though, research has shown that that the majority of bipolar I (94.2%) do report having at least one depressive episode (3). High mortality, disease burden, poor psychosocial functioning and well-being, are the adverse outcomes often experienced by individuals with bipolar disorders (4–7).
Impulsivity is a core putative feature of bipolar disorders (8, 9) that becomes elevated during mania (10). Impulsivity is typically conceptualized as the tendency to make rash decisions or responses that lead to undesirable consequences (11, 12). The inability to inhibit undesired actions can adversely impact various aspects of functioning due to a disregard for future consequences in favour of immediate rewards (13–15). Generally, trait (i.e., a predisposition toward rash actions) and behavioural facets (i.e., the lack of inhibition of ongoing actions, such as delay of gratification or response inhibition) of impulsivity are heightened in bipolar disorders (16–18). Given that impulsivity is a crucial disorder feature, research into both trait and behavioural facets of impulsivity has been ubiquitous. According to meta-analytic studies, behavioural aspects are significantly impaired with medium effect sizes (Hedge’s g estimates ranging from 0.41 to 0.51; (18, 19)), whereas trait aspects, such as motor, cognitive, and non-planning impulsivity, commonly measured by the Barratt’s Impulsivity Scale (BIS), too are, significantly elevated in bipolar disorders (17, 20). In addition, trait impulsivity is associated with disorder onset (21) and certain sub-features have been linked prospectively to illness severity (22).
One facet of impulsivity that has gained steady popularity in the recent few decades is emotional urgency, defined as a trait-tendency to react impulsively amidst strong emotions. Emotional urgency represents the combination of the two dimensions (negative and positive urgency) of the UPPS-P Impulsive Behaviour scale (Urgency, Perseverance, Premeditation, Sensation Seeking, and Positive Urgency) is an updated version of the original UPPS scale which features a total of five trait impulsivity dimensions: (lack of) premeditation, (lack of) perseverance, sensation seeking, negative and positive urgency (23). As positive urgency, originally operationalized from a standalone questionnaire called the Positive Urgency Measure (PUM; (24)), is most recent dimension incorporated by the UPPS-P, it is also the least studied. Negative and positive urgency are referred to as trait tendencies of rash action amidst negative and positive emotions respectively. Unlike other UPPS-P facets of impulsivity that are construed to operate separately from emotionality, emotional urgency represents a unique aspect of impulsivity that ties rash decision making with intense positive and negative emotions (25, 26).
The UPPS was originally formed by an amalgamation of various impulsivity constructs, with each of the final five constructs corresponding to a facet of the five-factor model of personality. As a trait concept, negative urgency clusters closely with the personality trait of neuroticism into a single factor (12). However, theories of emotional urgency have since moved beyond personality concepts due to a growth of neuroscience based research in cognition and emotion (27). Negative urgency has been associated with a neurocognitive vulnerability arising from reduced neurochemical activity or dysfunction in key neural areas of the ventromedial pre-frontal cortex and orbitofrontal cortex, resulting in less efficacious regulatory control over pathological impulses (i.e., addictive impulses) from the basal ganglia and extended amygdala, and emotional arousal from sensory and visceromotor circuitries within the orbitofrontal cortex (28–30). Emotional urgency is thus associated with impaired executive control and subsequently positively linked to greater risk-taking and maladaptive behaviours. Indeed, in an experimental study among non-clinical college students, it was found that only positive urgency (and not other facets of the UPPS-P) significantly uniquely predicted risk-taking and increased alcohol consumption after positive mood induction (31). When faced with social rejection, individuals with average to high levels of negative urgency were more likely than those with low levels to show increased impulsivity (failing to inhibit a prepotent response) due to the negative affect of social rejection (32). In both experiments, non-emotional facets of impulsivity failed to achieve similar results as urgency, suggesting their relative smaller roles. Emotional urgency have been important in predicting substance misuse (Smith and Cyders, 2016), gambling (33), drinking problems (34), however, the effect sizes are small (r = 0.23 for nicotine severity for instance; (35).
Personality constructs typically do not yield large effect sizes — a medium effect size of 0.29 corresponds to the 75th percentile of all personality correlations and less than 3% of all personality correlations documented are large (r ≥ 0.5;(36)). Using the cut-off at the 75th percentile, personality constructs with correlations of r ≥ 0.29 are considered to have large practical significance. A meta-analysis of 115 studies (N = 40432) found that emotional urgency had the greatest effect on general psychopathology (a medium effect, r = 0.34) whereas non-emotional aspects of impulsivity only had a small effect (r ranging from 0.08 to 0.14). More crucially, the meta-analysis found large effects on depression (r = 0.45) and borderline personality disorder (r = 0.58), implying that negative urgency has moderately high relevance in disorders of mood dysregulation.
While a large repertoire of existing research has been dedicated to the study of general impulsivity in bipolar disorders, most have not examined emotional urgency— it is unclear if there is sufficient empirical evidence for its clinical significance. Systematic reviews published thus far have synthesized important work in non-emotional constructs of impulsivity (18, 20), impulsivity constructs in relation to addictions and substance misuse (26, 29, 30, 37–40), problematic eating and related disorders (26, 41, 42), aggression (43), self-injurious behaviours (44), psychosis with comorbid substance use (45), and general psychopathology (46). However, to the best of knowledge, there have been no attempts to synthesize existing empirical evidence of positive and negative urgency in relation to important clinical and psychosocial factors in bipolar disorders.
Prevailing research shows that emotional urgency is more closely associated with psychopathology and externalizing behaviours (i.e., behaviours directed outwards or rule-breaking behaviours), such as outward aggression, gambling, substance use, than the remaining facets of the UPPS. Unlike other facets of UPPS, negative urgency is positively correlated with internalizing behaviours (i.e., behaviours that are inflicted inwards toward the self) with medium to large effect sizes, such as non-suicidal self-injurious behaviours (NSSI; d = .56 to .59, a medium effect size; (44, 47) and binge-eating (d = .64, a medium effect size; (41). Emotional urgency underlies many forms of behavioural addictions (48, 49), risk-taking behaviours (18), and to a lesser extent, suicidality (50). Further, mood instability, irritability, depression, and mania, are some instances of emotionality that, when heightened, can nudge individuals to engage in maladaptive behaviours (34, 41, 44, 46, 51). While the association between negative emotions and maladaptive behaviours is well known and accepted in psychopathology, few studies have investigated the role of emotional urgency in this relationship. Finally, where mania is the primary mood state of concern, support for the association between emotional urgency and mania remains unclear.
Considering the existing gaps in research on emotional urgency in bipolar disorders, we conducted a scoping review to answer a fundamental question, “what is the clinical significance and clinically relevant correlates of emotional urgency in bipolar disorder?” This approach was adopted over a systematic review to determine the extent of evidence in a niche area of study before proceeding with the latter approach. Thus, this review aims to, firstly, determine the extent of emotional urgency’s clinical relevance by qualitatively summarizing prevailing research that reported between group differences of emotional urgency scores (i.e. bipolar disorder vs healthy controls vs other clinical populations) and associations between emotional urgency and bipolar disorders (i.e. both categorical diagnosis and continuous symptom measures); and secondly, summarize clinically relevant associations of emotional urgency and all aspects relevant to illness (e.g., aetiological factors and clinical outcomes, psychiatric comorbidities), psychosocial outcomes (e.g. functioning or quality of life), and maladaptive behaviours (e.g., suicidality, self-harm) in individuals with bipolar disorders.