The Role of Nonplanning Impulsivity in Predicting Depression and Anxiety Among Individuals with Severe Mental Illness after Psychiatric Hospital Discharge

Background/Purpose The role of impulsivity in psychiatric illness is not well understood. Little work has been done to clarify the role of impulsivity in mood disorders such as depression and anxiety. Impulsivity is considered a clinical state as well as stable trait; however, this possibility has been largely understudied in previous research. There are inadequate longitudinal studies to differentiate the relative roles of state impulsivity from trait impulsivity as related to depression and anxiety. Additionally, the specific relationships between depressive or anxious symptoms and specific aspects of impulsivity have been rarely investigated. Cross-sectional data indicate that one aspect of impulsiveness―nonplanning impulsivity (or lack of sense of the future as measured by the Barratt Impulsiveness Scale [BIS-11])—may be related to hopelessness and depression. Thus, nonplanning impulsivity is decomposed into state and trait components to test the separate longitudinal effects on depression and anxiety among discharged psychiatric patients.

Methods This research used the MacArthur Violence Risk Assessment Study of 1134 post-discharge psychiatric patients. Depression and anxiety were measured using the Brief Psychiatric Rating Scale. Nonplanning impulsivity was measured by 9-items obtained from the BIS-11 at baseline, 10-weeks, and 30-weeks post-discharge. Hierarchical Linear Modeling techniques were employed within this analysis by constructing individual linear growth curve models. To capture the compositional effects of state and trait nonplanning impulsivity in these models, time-varying impulsivity was person (or group) mean-centered at Level 1 with reintroduction of the aggregates (of impulsivity) at Level 2 adjusting for marriage, age, gender, and SES. This strategy provides unbiased estimates of the orthogonal effects of state (time-varying) and trait (time-invariant) impulsivity on depression and anxiety.

Results Increases in nonplanning impulsivity significantly predicted changes in depression among discharged patients. Specifically, trait nonplanning impulsivity was significant for changes in depression over the course of study (B = .009, p <.01). State nonplanning impulsivity did not predict changes in depression. Both trait and state nonplanning impulsivity were unrelated to changes in anxiety.

Conclusions and Implications Discharge from psychiatric hospitals is a critical period for many individuals. The transition itself may be experienced as a stressful life event as these individuals integrate back into their day-to-day lives. The clinical relevance of this study is underscored by the findings that impulsivity can be comprised of state and trait components and that trait impulsivity was a more powerful predictor of depression rather than state impulsivity during this transition period. Trait impulsivity has its roots in genetic endowment; however, more negative attribution of stressful life events or greater exposure to such events among impulsive individuals could also potentially explain their increased risk of depression. Taken together, our findings highlight an important insight for social work practitioners to help individuals as they transition from psychiatric hospitals to the community by considering the role of nonplanning impulsivity on outcomes of depression.