Mood instability underlies the relationship between impulsivity and internalizing psychopathology

Area of Science:

• Psychiatry
• Clinical Psychology
• Behavioral Science

Background:

• Impulsivity and mood instability are linked to internalizing disorders.
• The precise relationship between impulsivity, mood instability, and internalizing psychopathology requires further elucidation.

Purpose of the Study:

• To investigate the mediating role of mood instability in the association between impulsivity and internalizing psychopathology.
• To examine this relationship in both cross-sectional and longitudinal data.

Main Methods:

• Two studies utilized existing datasets (Adult Psychiatric Morbidity Survey, British Health and Lifestyle Surveys).
• Sequential regression analyses were employed to test the hypothesized mediation.
• Measures included the Structured Clinical Interview for DSM-IV Axis-II Personality Disorders, revised Clinical Interview Schedule, Eysenck Personality Inventory, and General Health Questionnaire.

Main Results:

• In Study 1, the link between depression and impulsivity was non-significant when mood instability was accounted for.
• In Study 2, impulsivity's predictive effect on future internalizing symptoms became non-significant after including mood instability.
• Mood instability significantly mediated the relationship between impulsivity and internalizing psychopathology in both studies.

Conclusions:

• The association between impulsivity and internalizing psychopathology is largely explained by mood instability.
• Clinical interventions for internalizing conditions may benefit from focusing on mood instability rather than impulsivity directly.