Impulsivity and reward sensitivity within the pen model: A test of discriminant hypotheses

Impulsivity and Behavior-Dependent Life Events Mediate the Relationship of Reward Sensitivity and Depression, but Not Hypomania, Among at-Risk Adolescents

Both reward sensitivity and impulsivity are related to the development and course of bipolar spectrum disorders (BSDs) and have been implicated in other disorders and negative functional outcomes such as substance abuse, obesity, suicidal behaviors, and risk-taking. Furthermore, according to the transactional component of the Behavioral Approach System (BAS)/reward hypersensitivity theory of BSDs, people with reward hypersensitivity should experience more BAS-relevant events, and thus, are more vulnerable to mood symptoms and episodes via stress generation. Impulsivity may exacerbate stress generation in individuals at risk for BSDs based on exhibiting reward hypersensitivity. The current study examined whether impulsivity explained the generation of stress and subsequent mood symptoms beyond what is explained by reward sensitivity alone. Participants were 131 Moderate BAS and 216 High BAS sensitivity adolescents (M = 18.43 years, SD = 1.40), who completed baseline measures of reward sensitivity and impulsivity, as well as follow-up measures of life events and mood symptoms. Results from linear regression analyses indicated that higher baseline impulsivity predicted behavior-dependent, but not behavior-independent, life events. Furthermore, path analyses suggested that the effect of BAS group on depression symptoms at next follow-up was partly explained via the indirect effect of impulsivity and negative behavior-dependent life events. We did not find these effects for behavior-independent or positive-dependent events or for prediction of hypomanic symptoms. The findings suggest that impulsivity may account for stress generation of negative events that precede depression.

Further evidence of the heterogeneous nature of impulsivity

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Impulsivity is not a unitary construct and instead comprises dissociable subtypes.

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Reflection-impulsivity is a distinct and well-defined facet of impulsivity.

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Additional characterisations of motor-impulsivity are required.

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Several tasks purported to index impulsivity should be treated with caution.

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Researchers should employ multiple measures of types of impulsivity simultaneously.

‘Impulsivity’ refers to a range of behaviours including preference for immediate reward (temporal-impulsivity) and the tendency to make premature decisions (reflection-impulsivity) and responses (motor-impulsivity). The current study aimed to examine how different behavioural and self-report measurements of impulsivity can be categorised into distinct subtypes.

Exploratory factor analysis using full information maximum likelihood was conducted on 10 behavioural and 1 self-report measure of impulsivity.

Four factors of impulsivity were indicated, with Factor 1 having a high loading of the Stop Signal Task, which measures motor-impulsivity, factor 2 representing reflection-impulsivity with loadings of the Information Sampling Task and Matching Familiar Figures Task, factor 3 representing the Immediate Memory Task, and finally factor 4 which represents the Delay Discounting Questionnaire and The Monetary Choice Questionnaire, measurements of temporal-impulsivity.

These findings indicated that impulsivity is not a unitary construct, and instead represents a series of independent subtypes. There was evidence of a distinct reflection-impulsivity factor, providing the first factor analysis support for this subtype. There was also support for additional factors of motor- and temporal-impulsivity. The present findings indicated that a number of currently accepted tasks cannot be considered as indexing motor- and temporal-impulsivity suggesting that additional characterisations of impulsivity may be required.

Cross-cultural validity of the I7 impulsiveness-venturesomeness-empathy scales: evidence from the Italian I7

The cross-cultural generalizability of Impulsiveness-Venturesomeness-Empathy questionnaire (I(7)) is investigated with a sample of 578 Italian adults, mostly nonstudents. Results indicate that Italian I(7) scale intercorrelations and reliabilities were similar to those obtained in other cultural contexts; furthermore, the 3-factor structure is generalizable across sexes and invariant compared with the English normative structure, as well as with those found in the French, Dutch, and Spanish versions. Impulsiveness was positively correlated with Barratt Impulsiveness Scale and with Dickman's dysfunctional impulsivity scale but independent of the functional impulsivity scale. Plotting the scale onto the Eysenck's psychoticism-extraversion-neuroticism factor space, impulsiveness was more strongly related to psychoticism and neuroticism than to extraversion. We remark that the impulsiveness measure of I(7) is fairly stable across languages and cultures and can be used reliably in Italian speaking samples.