Relationships between hypomanic symptoms and impulsivity and risk-taking propensity in an international sample of undergraduate students.

This study examined relationships between hypomanic symptoms and impulsivity and risk-taking propensity in an international sample of 246 undergraduate students, finding statistically significant positive correlations between hypomania and impulsivity and risk-taking propensity. Multiple regression analyses provided further insight into these relationships.

Introduction

According to the American Psychiatric Association’s Diagnostic and Statistical Manual of Mental Disorders, fourth edition (DSM-IV-TR), a ‘hypomanic episode’ is mental illness characterised by symptoms such as a decreased need for sleep, flight of ideas, increased talkativeness, grandiosity, and an increase in goal-directed activity (APA, 2000). These symptoms occur within an elevated or irritable mood which lasts for at least 4 days. Multiple episodes of hypomania and depression warrant a diagnosis of bipolar II disorder (APA, 2000). A number of the DSM-IV-TR diagnostic criteria for hypomania suggest impulsive and risk-taking behaviours. For example, Criterion B states possible symptoms of “increased involvement in pleasurable activities that have high potential for painful consequences” (APA, 2000, p. 365). Criterion B5 also states that “Distractibility is often present, as evidenced by rapid changes in speech or activity as a result of responding to various irrelevant external stimuli” (APA, 2000, p. 366), and criterion B7 states that “there may be impulsive activity such as buying sprees, reckless driving, or foolish business investments” (APA, 2000, p.366).

A number of lines of evidence suggest that hypomania is related to impulsivity and risk-taking behaviours. Impulse Control Disorders (ICDs) and bipolar disorders share a number of features, including symptom similarities (McElroy et al., 1996). For example, both mania and ICDs are often characterised by impulsive and risk-taking behaviours, such as gambling, excessive spending and promiscuous sexual activity. There are also high levels of comorbidity between ICDs and bipolar disorders (McElroy et al., 1991; McCormick et al., 1984). Trait impulsivity appears to be important in bipolar disorders, being present in 41% of those with bipolar II disorder (Benazzi, 2007a). Bipolar patients have been shown to have elevated scores on measures of trait impulsivity such as the Barratt Impulsivity Scale (Peluso et al., 2007), as well as on behavioural measures of response inhibition (Swann et al., 2009b.). Impulsiveness is related to symptom severity (Benazzi, 2007a; Lewis, Scott & Fran, 2009), and is associated with a worse course and outcome (Barratt et al., 2009a). Impulsive personality scores may increase vulnerability to mania, as they predict a later diagnosis of bipolar disorder (Kwapil et al., 2000). Trait impulsivity in bipolar disorder has been shown to be elevated in those with a history of suicide attempts (Michaels et al., 2004; Swann et al., 2009a,b), and to correlate with seriousness of suicide attempt (Swann et al., 2007; Swann et al., 2005). It may also explain some of the common co-morbidities observed in bipolar disorder, including high levels of alcohol use (Swann et al., 2007; Holmes et al., 2009), drug use (Swann et al., 2004), anxiety (Taylor et al., 2008) and borderline personality disorder (Benazzi et al., 2008).

There is also evidence to suggest that impulsivity is an important state component in bipolar disorder. Impulsivity is a key symptom of mania (Swann et al., 2001a), and whilst there is considerable variation in the symptom presentations of manic episodes, impulsivity is a consistent symptom (Swann et al., 2001b). During an episode, levels of impulsivity may be related to the severity of the episode (Swann et al., 2007). Subsequently it has been suggested that impulsivity may predict response to treatment for mania (Moeller et al., 2001). Thus, impulsivity is an important part of bipolar disorder, having both trait and state components (Swann et al., 2003). Research suggests that hypomania specifically is directly linked to impulsivity. For example Kwapil et al. (2000) found that high scorers on the ‘hypomanic personality scale’ (Eckblad & Chapman, 1986) had elevated scores on the impulsive-nonconformity scale (Chapman et al., 1984). However, with few exceptions (e.g., Durbin et al., 2009), there has been little research examining the relationships between hypomanic and impulsive symptoms in non-clinical populations. Further, there has been little work addressing the relationship between hypomania and risk-taking behaviours specifically. The aim of this study was therefore to ascertain if hypomanic symptoms are related to impulsivity and risk-taking propensity in a non-clinical international sample of undergraduate students.

Method

Participants
Participants were invited to take part in the study through emails sent to psychology departments in English speaking countries. Additionally, some students completed the survey as part of an undergraduate research credit scheme at Trinity College, University of Dublin, Ireland. The data set consists of undergraduate students of British, Irish, Australian, New Zealand, United States and Canadian nationality who completed all of the standardised measures used here. A total of 246 participants met these criteria. The gender distribution was 14% male (n=34), 86% female (n=208). Four participants did not report their gender. Ages ranged from 18 to 65, with a mean of 22.26 (SD=6.11) years. Nationalities were 37.4% British (n=92), 26.4% Irish (n=65), 16.3% U.S. (n=40), 9.3% New Zealander (n=23), 8.1% Australian (n=20) and 2.4% Canadian (n=6).

Instruments
Participants completed an online battery consisting of:
- The 32-item Hypomania Checklist (HCL-32) (Angst et al., 2005a). This is a self-report measure of 32 questions, which measures the severity of previous hypomanic episodes by asking patients to think of a time when they were in a ‘high’ state. Participants have to respond ‘Yes’ or ‘No’ to a list of 32 hypomanic symptoms such as “I am more talkative”. Scores range from 0-32, with a score of 14 or more discriminating between major depressive disorder and bipolar disorder with a sensitivity of 80% and a specificity of 51% (Angst et al., 2005a). The Chronbach’s alpha values obtained for this measure in the current sample are given in table 1.

- The Barratt Impulsiveness Scale version 11 (BIS, Barratt, 2000). This is a self-report measure of 30 questions. This measures general impulsiveness, with a number of subscales assessing different aspects of impulsivity, such as ‘attentional impulsiveness’, e.g. “I don’t pay attention” and ‘cognitive instability’ e.g. “I like to think about complex problems”. Questions are answered and scored from 1 point for ‘Rarely/Never’ to 4 for ‘Almost always/Always’. Subsequently, scores range from 30 to 120. The Chronbach’s alpha values obtained for this measure in the current sample are given in table 1.

- The Domain-Specific Risk-Taking Scale- Likelihood Scale (DOSPERT, Blais & Weber, 2006). This is a self-report measure of 30 questions. This measures the self-reported likelihood of engaging in risk-taking behaviours. A total of five subscales are present such as ‘Financial’ e.g. “Investing 10% of your annual income in a new business venture’ and ‘Health and Safety’ e.g. “Engaging in unprotected sex”. Questions are answered on a Likert scale of 1 for extremely unlikely and 7 for extremely likely, with subsequent total scores ranging from 30 to 210. An increased score represents an increased likelihood of engaging in risky behaviours. The Chronbach’s alpha values obtained for this measure in the current sample are given in table 1.

Procedures
Ethical approval for this study was gained through the Trinity College Dublin School of Psychology research ethics board. The standardised measures used were completed online along with consent and debriefing forms. Participants could leave the survey at any stage and did not have to answer any questions they did not want to. No identifying personal information was requested by the researchers, giving anonymity to the participants.

Table 1: Chronbach’s alpha values for measures used obtained with the current sample

Results

Score ranges
HCL-32 total scores ranged from 4-31 out of 32, with a mean of 18.2 (SD=5.05). BIS total scores ranged from 39 to 104 out of 120, with a mean of 64.96 (SD=11.10). DOSPERT likelihood total scores ranged from 47 to 182 out of 210, with a mean of 101.5 (SD=21.74).

Overall correlations
The HCL-32 total was significantly positively correlated with the DOSPERT total; r=.26, p<.001, one-tailed, and BIS total; r=.39, p<.001, one-tailed. The DOSPERT total and BIS total were also significantly positive correlated; r=.378, p<.001, one-tailed.

General hypomanic symptoms and impulsivity
A multiple regression was conducted with the HCL-32 total as the dependent variable and the BIS subscales as the predictors. Overall, there was a statistically significant relationship between the BIS subscales and the HCL-32 total- F=9.376, p<.001 (R2 =.191). Table 2 presents the standardised coefficients for each subscale of the BIS as the predictors, and the subscales of the HCL-32 as the dependents. As table 2 demonstrates, the attention and motor impulsivity subscales of the BIS were both independent predictors of the HCL-32 total.

Table 2: Standardized Coefficients for BIS subscales as predictors and HCL-32 subscales as dependents

Active/Elevated hypomanic symptoms and impulsivity
A standard multiple regression was conducted with the HCL-32 Active/Elevated subscale as the dependent variable and the BIS subscales as the predictors. Overall there was a statistically significant relationship between the BIS subscales and the HCL-32 Active/Elevated subscale- F=4.013, p<.001 (R2 =.092). As table 2 demonstrates, the only significant independent predictor of the HCL-32 Active/Elevated subscale was the Self Control subscale of the BIS.

Risk-Taking/Irritable hypomanic symptoms and impulsivity
A standard multiple regression was conducted with the HCL-32 Risk-Taking/Irritable subscale as the dependent variable and the BIS subscales as the predictors. Overall there was a statistically significant relationship between the BIS subscales and the HCL-32 Risk-Taking/Irritable subscale- F=11.475, p<.001 (R2 =.224). As table 2 demonstrates, the Attention and Motor subscales of the BIS were significant independent predictors of scores on the HCL-32 Risk-Taking/Irritable subscale.

General hypomanic symptoms and risk-taking propensity
A standard multiple regression was conducted with the HCL-32 Total as the dependent variable and the DOSPERT subscales as the predictors. Overall there was a statistically significant relationship between the DOSPERT subscales and the HCL-32 Total- F=4.507, p<.001 (R2 = .086). Table 3 presents the standardised coefficients for each subscale of the DOSPERT as the predictors, and the subscales of the HCL-32 as the dependents. As table 3 demonstrates, none of the subscales of the DOSPERT were significant independent predictors of scores on the HCL-32 total.

Table 3: Standardized Coefficients for DOSPERT subscales as predictors and HCL-32 subscales as dependents

Active/Elevated hypomanic symptoms and risk-taking propensity
A standard multiple regression was conducted with the HCL-32 Active/Elevated subscale as the dependent variable and the DOSPERT subscales as the predictors. Overall, there was not a statistically significant relationship between the DOSPERT subscales and the HCL-32 Active/Elevated subscale- F=1.006, p>.05 (R2 =.021). As table 3 demonstrates, none of the subscales of the DOSPERT were significant independent predictors of scores on the HCL-32 Active/Elevated subscale.

Risk-Taking/Irritable hypomanic symptoms and risk-taking propensity
A standard multiple regression was conducted with the HCL-32 Risk-Taking/Irritable as the dependent variable and the DOSPERT subscales as the predictors. Overall, there was a statistically significant relationship between the DOSPERT subscales and the HCL-32 Risk-Taking/Irritable subscale- F=9.362, p<.001 (R2=.163.). Table 6 presents the standardised coefficients for each subscale. As table 3 demonstrates, the Ethical and Health/Safety subscales of the DOSPERT were significant independent predictors of scores on the HCL-32 Risk-Taking/Irritable subscale.

Demographic interactions
Analyses were conducted on all statistically significant predictors to determine the effects of demographic variables of age, nationality and gender on relationships. Three significant differences were found. Specifically, there was a significant effect of age on the relationship between the HCL-32 Risk-Taking/Irritable subscale and the BIS Motor subscale; t=2.205, p<.05, with the relationship being stronger with increasing age. There was also a significant effect of age on the relationship between the HCL-32 Risk-Taking/Irritable subscale and the DOSPERT Ethical subscale; t=-3.253, p<.05, with the relationship being weaker with increasing age. Finally, there was a significant effect of gender on the relationship between the HCL-32 Risk-Taking/Irritable subscale and the DOSPERT Health/Safety subscale; t=-2.019, p<.05, with the relationship being stronger for women.

Discussion

This study examined the relationship between hypomanic symptoms and impulsivity and risk taking propensity in an international sample of undergraduate students. The results suggest overall strong positive correlations between symptoms of hypomania and impulsivity and risk-taking propensity in this non-clinical population. This suggests strong ‘dose-response’ relationships, with increased impulsivity being associated with increasingly severe hypomanic symptoms. This is in line with previous findings of positive correlations between manic severity and impulsivity (Benazzi, 2007a; Lewis et al., 2009; Swann et al., 2007, 2008).

Whilst total scores were significantly correlated, multiple regression analyses were required to determine which specific aspects of hypomania were related to which specific aspects of impulsivity in this population. The analyses suggested that when the other subscales were held constant, only a few aspects of impulsivity were independently related to hypomanic symptoms. For example, although total BIS score predicted HCL-32 total and Risk-Taking/Irritable subscale, only the Attention and Motor subscales were independently related to these hypomania subscales. This is in line with DSM-IV-TR criteria for a hypomanic episode, for example criterion B5 (APA, 2000, p. 365) states that a potential symptom is ‘Distractibility (i.e. attention too easily drawn to unimportant or irrelevant external stimuli), which is reflected in the Attention subscale of the BIS. Previous research has also documented impaired attention in those with bipolar disorder (Swann et al., 2009b). Also the Motor subscale of the BIS would appear to capture an important aspect of criterion B6, which states that ‘psychomotor agitation’ may be present (APA, 2000, p. 365). Swann et al (2009b) found that patients with bipolar disorder were poor at inhibiting rapid motor responses, suggesting that motor impulsivity may be an important part of manic sympomatology. The specific aspects of impulsivity measured by the BIS including Self-control, Cognitive Complexity, Perseverance and Cognitive Instability were not related to general hypomania and irritable and risk-taking symptoms in this sample. This suggests that, in non-clinical populations at least, general hypomanic symptoms and those of irritability and risk-taking are related to specific impulsive symptoms of attention and motor impulsivity.

Although the HCL-32 Active/Elevated subscale was significantly related to the overall BIS score, only the self-control subscale of the BIS was related to this aspect of hypomania. This relationship with self-control may be related to the potential symptoms specified in criterion B7 of the DSM-IV-TR such as unrestrained buying sprees and sexual indiscretions. Previous research has also documented poor self control associated with hypomania and bipolar disorder as demonstrated by excessive spending (Akiskal & Pinto, 1999), and increased sexual promiscuity (Dell’Osso et al., 2009). Thus, in non-clinical populations, hypomania elation may also be related to a lack of self-control and may result in unrestrained actions such as these. However, overall active and elevated aspects of hypomania do not appear to be as strongly related to impulsivity as general hypomanic symptoms and risk-taking and irritable symptoms. This suggests that risk-taking and irritable hypomanic symptoms are more impulsive than active or elevated symptoms. Thus, an irritable mood whilst hypomanic may be associated with greater impulsivity than when mood is elated. This may be important as it suggests that different mood presentations may require different treatments for the subsequent severity of accompanying impulsivity. However it is important to note that the present study examined symptoms in the general population, and this may not necessarily be the case for clinical hypomanic episodes and bipolar disorder.

The DOSPERT, measuring risk-taking propensity, was less strongly related to hypomania in this sample. The total HCL-32 score was significantly predicted by all the DOSPERT subscales combined, but no subscale individually. This suggests that general hypomanic symptoms are related to general increased risk-taking propensity, but no specific type of risk taking appears to be particularly elevated. However it is important to consider that the total scores may simply be more reliable than the individual subscales; as table 1 shows the chronbach’s alpha scores are higher for the total scores than the subscales. Therefore, in this non-clinical population, hypomanic symptoms are strongly related to the likelihood of engaging in potentially risky behaviours. This again is in line with DSM-IV-TR diagnostic criteria of “increased involvement in pleasurable activities that have high potential for painful consequences” (APA, 2000, p. 365), and is in accordance with previous research documenting negative consequences of hypomania such as increased marital disruption (Angst, 1998), and high comorbidity between bipolar disorder and impulse control disorders such as kleptomania (McElroy et al., 1991) and pathological gambling (McCormick et al., 1984). However it appears that no specific types of risk-taking, such as ethical or financial risks, are independently related to hypomania, but rather increased hypomania is related to a general increase in risk-taking propensity.

The Active/Elevated subscale of the HCL-32 was not significantly related to the subscales of the DOSPERT, whilst the HCL-32 Risk-Taking/Irritable subscale was. This suggests that risk-taking symptoms are rarely related to active and eleated symptoms in non-clinical populations, and are more commonly associated with risk taking and irritable hypomanic symptoms. Therefore risk-taking behaviours may be more common when the mood accompanying hypomania is irritable rather than elated. The Ethical and Health/Safety subscales were independently related to the HCL-32 risk-taking subscale. This suggests that ethical risks given by the DOSPERT, such as ‘Having an affair with a married woman’, and Health and Safety risks, such as ‘Driving a car without a seatbelt’ are particularly related to the irritable symptoms accompanying hypomania. This would be in line with DSM-IV-TR symptoms and previous research (Akiskal & Pinto, 1999), but it should be noted that the hypomania here probably represents sub-clinical hypomania.

It is interesting to note that some of the relationships between hypomania and impulsivity and risk-taking propensity described above were influenced by demographic variables. Increasing age was associated with a stronger relationship between the HCL Risk-Taking/Irritable subscale and the BIS motor scale, suggesting that psychomotor agitation association may be more pronounced and more strongly associated with an irritable mood in those of increasing age. On the other hand it appears that this subscale’s relationship with the DOSPERT ethical subscale was associated with age in the reverse direction, suggesting that hypomania may be associated with greater ethical risks, such as “Passing somebody else’s work as your own” in those of a younger age. Previous work suggests that age effects impulsivity and sensation seeking propensity (Steinberg et al., 2008). The current results demonstrate that this may also be the case for the relationship between impulsive and risk-taking symptoms and bipolar affective symptoms. Gender also affected the relationship between this subscale and the DOSPERT Health/Safety subscale, with a stronger relationship for women. This suggests that increasing hypomania symptoms, and specifically an irritable mood, may be more likely to result in individuals taking health and safety risks, such as ‘Walking home alone at night in an unsafe area of town’, in women than in men. This is in line with various pieces of research demonstrating a number of gender differences in bipolar disorder (Arnold, 2003). However it goes against research which suggests that men with bipolar disorder are more likely than women to experience comorbidities related to impulsivity and risk-taking such as alcohol use and gambling problems (Kawa et al., 2005). These results tentatively suggest that hypomania may be associated with impulsivity and risk-taking propensity in a different way for those of a differing age, and that gender may also affect the relationship. However, it should be noted that this study examined such symptoms in a non-clinical population, and also the low number of males in the sample may have affected statistical relationship with gender observed here.

Whilst previous research on clinical populations demonstrates the importance of impulsive personality traits in hypomania (Benazzi, 2007), this suggests that such a relationship exists in non clinical populations. Previous work suggests that such a relationship exists within the general population in terms of personality traits (Durban et al., 2009), and this study suggests that this may also be the case for sub-clinical hypomanic symptoms. However, the nature of causality in these results is unclear. It could be that increased impulsivity increases the severity of hypomania; previous research demonstrates that impulsivity predicts bipolar disorder at follow up (Kwapil et al., 2000). Equally, it could be that increased severity of hypomania increases subsequent impulsiveness; previous research demonstrates that impulsivity is a key symptom during manic episodes (Swann et al., 2001a). Related to this is whether the findings suggest that trait or state impulsivity is important in hypomania. Whilst the BIS generally measures trait impulsivity, it is possible that it is also picking up on state impulsivity during (probably subclinical) hypomanic episodes. Thus whilst this research may suggest that trait impulsivity is strong in those with hypomanic tendencies, it may also imply that hypomanic episodes are associated with state impulsivity, in line with previous research on the symptoms of mania (Swann et al., 2001a; Swann et al., 2001b). It is also possible that impulsivity represents both a trait and state component in hypomania, in line with previous research on bipolar II patients (Benazzi, 2007). Whether impulsivity is a trait or state, this research suggests that impulsivity and risk taking behaviours are related in a dose-response manner to hypomanic symptoms in non-clinical populations. Thus impulsivity and risk-taking propensity may need to be taken into consideration during the assessment and treatment of hypomania, in line with previous research suggesting that increased impulsivity increases the severity of manic symptoms (Swann et al., 2008; Swann et al., 2007).

A number of limitations of this study need to be considered. First, the sample consists of psychology undergraduate students, and as a result is predominantly female. Research has demonstrated that hypomania may be more prevalent in women (Angst et al., 2005b), and research also shows gender differences in impulsivity and risk-taking behaviours (D’Acremont & Van Der Linden, 2005). Second, as previously mentioned, it is important to understand that the sample is non-clinical, and thus the hypomanic symptoms measured here probably represent subclincial hypomanic symptoms, and thus it cannot be confidently suggested that DSM-IV-TR hypomanic episodes will be related to impulsivity and risk-taking behaviours in the same way. Third, the HCL-32 was developed to distinguish unipolar depression from bipolar II disorder, and thus is not intended for use in non-clinical populations. However, research has shown that the HCL-32 can detect hypomanic symptoms in non-clinical groups (Vieta et al., 2007). Similarly, as table 1 shows, whilst most of the chronbach’s alpha scores obtained with this sample were satisfactory, a number of subscales had low scores, questioning the reliability of their use in this current non-clinical sample. Finally, due to the number of multiple regressions calculated, there is an inflated experimentwise alpha level, and therefore it is possible that some of the significant correlations here represent type I errors.

Conclusion

This study examined relationships between hypomanic symptoms and impulsivity and risk-taking behaviours in an international sample of undergraduate students, finding that the two are related, with specific aspects of impulsivity and risk-taking being related to specific hypomanic symptoms. This study has a number of limitations, but suggests that hypomania is related to impulsivity and risk-taking propensity in non clinical populations. These findings give insight into the potentially negative consequences of hypomania, such as foolish business investments and spending sprees, in line with DSM-IV-TR diagnostic criteria, and previous research. Future research should use structured clinical interviews and examine the relationships in clinical bipolar populations, and should also try to clarify whether impulsivity and hypomania are related via trait or state characteristics.

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Relationships between hypomanic symptoms and impulsivity and risk-taking propensity in an international sample of undergraduate students.

Thomas Richardson
Mental Health Research and Development Unit, University of Bath, U.K.
School of Psychology, Trinity College, University of Dublin, Ireland

Hugh Garavan2*
School of Psychology, Trinity College, University of Dublin, Ireland

Abstract

Introduction

Method

Results

Discussion

Conclusion

References

Relationships between hypomanic symptoms and impulsivity and risk-taking propensity in an international sample of undergraduate students.

Thomas Richardson Mental Health Research and Development Unit, University of Bath, U.K. School of Psychology, Trinity College, University of Dublin, Ireland

Hugh Garavan2* School of Psychology, Trinity College, University of Dublin, Ireland

Abstract

Introduction

Method

Results

Discussion

Conclusion

References

Thomas Richardson
Mental Health Research and Development Unit, University of Bath, U.K.
School of Psychology, Trinity College, University of Dublin, Ireland

Hugh Garavan2*
School of Psychology, Trinity College, University of Dublin, Ireland