This study examined the relationships between a self-report measure of the behavioral activation system and concurrent manic and depressive symptoms, and between a measure of the behavioral inhibition system and anxiety symptoms in a small sample (n = 25) of bipolar adolescents. We hypothesized that high and low BAS scores would correlate with manic and depressive symptomatology, respectively. We also expected that higher BIS scores would be associated with higher self-reported anxiety symptoms.
Contrary to our hypotheses, we found evidence of high BAS functioning in adolescents with lower mania symptom severity scores. Bipolar adolescents who obtained higher scores on the BAS reward responsiveness and drive subscales had lower severity ratings on the motor-activity-based mania factor scores. These data are inconsistent with findings reported by other investigators (e.g. Meyer et al., 2001
) who found that high BAS sensitivity levels predicted an escalation of manic symptoms over time. In addition, we found no evidence for a link between BAS sensitivity and depressive symptomatology in this sample. This, again, is inconsistent with prior research which indicated that low BAS strength is associated with depressed states (Beevers and Meyer, 2002
; Kasch et al., 2002
Our analyses of BIS and anxiety symptomatology supported Quay’s (1993)
theorized link between BIS and anxiety in adolescents. In this study, bipolar adolescents who obtained high scores on the BIS scale reported higher levels of anxiety symptoms on the SCARED. These data replicate work that has found high levels of BIS sensitivity in individuals reporting high levels of anxiety (Carver and White, 1994
; Gray, 1981
). They also support the clinical observation that bipolar adolescents are often highly anxious (Birmaher et al., 2002
; Masi et al., 2004
Secondarily, we found that adolescents reporting higher levels of the motor activity symptoms of mania obtained higher scores on the anxiety symptom scale. This link supports previous work that has found high rates of comorbidity between bipolar and anxiety disorders in adult and pediatric samples (Freeman et al., 2002
; Masi et al., 2001
). Our results may also indicate that mania and anxiety are not truly independent clinical states in juvenile-onset populations. Adolescents with manic symptoms may exhibit symptoms typically associated with anxiety, such as physical agitation and avoidance, more so than classic mania symptoms, such as elation. Likewise, highly anxious bipolar patients may experience racing thoughts, rumination and restlessness, symptoms which may overlap with or be mistaken for mania.
Adolescents reporting higher levels of anxiety and behavioral inhibition also reported higher levels of suicidality in the three months prior to their assessments, as measured by a composite score of the number, medical lethality and seriousness of all reported suicide attempts/gestures reported on the K-SADS-DRS. Our findings extend research which has found that bipolar adults with high levels of anxiety are more likely to exhibit suicidal behavior (Young et al., 1993
). They also support the findings of Akiskal et al. (2005)
that among adults with unipolar major depressive disorder, psycho-motor activation and racing thoughts independently predict suicidal ideation. Thus, mood episodes characterized by mixed symptoms may be a risk factor for suicidality among adults and adolescents.
This study did not address whether BIS/BAS levels are stale over time and over clinical state in bipolar adolescents. Our findings may have been compatible with hypothesized linkages between BIS/BAS levels and mood if a greater number of our participants had been in acute clinical states during the BIS/BAS assessments. It remains for future research to investigate whether the relationships we obtained reflect the influences of states versus traits in bipolar adolescents.
The cross-sectional design of this study also prohibited us from examining whether the type of treatment offered (family-focused or brief psychoeducation, both given with pharmacotherapy) differentially affected the associations between BAS levels and mania/depression outcomes. The recruitment for this study was unique in that the type of treatment adolescents received was controlled–they were assigned to a 3-session or 21-session psychosocial treatment protocol. Future research would benefit from taking treatment variables into account and examining whether baseline levels of BIS/BAS interact with treatment type in predicting the course of mood symptoms over time.
Our findings suggest that clinicians need to address symptoms of anxiety directly in their treatment approaches to bipolar teens, including a thorough assessment of whether the mood disorder is comorbid with an anxiety disorder. In addition to pharmacologic interventions, clinicians should consider incorporating traditional anxiety treatments, such as relaxation training, exposure or emotional distress tolerance techniques found in protocols such as dialectical behavior therapy (Linehan, 1993
Despite the limitations of a cross-sectional design and a small sample size, our study suggests that BAS functioning is inversely related to mania symptomatology among bipolar adolescents. In addition, mood symptoms in adolescent populations may be closely tied to components of anxiety such that the more anxious adolescents report more severe manic symptoms. Taken together, these data suggest that the moods of bipolar adolescents include elements of anxiety which may lead to diminished approach behaviors. Future research should examine whether BIS and BAS functioning in bipolar adolescents represent vulnerability markers that place patients at higher risk for recurrences, and whether the effectiveness of interventions are moderated by baseline levels of BIS or BAS functioning.