Psychological predictors of bipolarity in panic disorder

BACKGROUND Panic disorders frequently occur with affective disorders, particularly bipolar disorder. Patients with panic disorder and bipolar disorder are more likely to present with severe symptoms, such as high rates of suicidal behavior, poor symptomatic and functional recovery, and poor drug responses. AIM To investigate the psychological characteristics of panic disorder patients related to bipolarity. METHODS A total of 254 patients (136 men and 118 women, mean age = 33.48 +/- 3.2 years) who were diagnosed with panic disorder were included in the study. Panic disorder with bipolarity (BP+) was defined as a score of 7 on the Korean version of the Mood Disorder Questionnaire (K-MDQ), and a score lower than 7 was considered as a panic disorder without bipolarity (BP-). Self-report questionnaires were analyzed to examine their association with bipolarity. Psychological tests used in the study were the Mood Disorder Questionnaire (MDQ), Panic Disorder Severity Scale, Beck Depression Inventory, State-Trait Anxiety Inventory (STAI), Temperament and Character Inventory (ICI), and Minnesota Multiphasic Personality inventory (MMPI). Statistical analyses were performed to evaluate the correlation between bipolarity of panic disorder patients and various psychological test results indicative of psychological characteristics. RESULTS Patients with a K-MDQ score of 7 or more were considered to have a history of manic or hypomanic episodes (BP+ group, n = 128), while patients with K-MDQ scores below 7 were defined as those without bipolarity (BP- group, n = 126). The BP+ group were more likely to be unmarried (single 56.2% vs 44.4%, P = 0.008) and younger (30.78 +/- 0.59 vs 37.11 +/- 3.21, P < 0.001). Additionally, the BP+ group had significantly higher scores on psychological assessment scales, such as the hypochondriasis, psychopathic deviate, masculinity-femininity, psychasthenia, schizophrenia, and hypomania (Ma) in MMPI, and novelty seeking, harm avoidance and self-transcendence in ICI, and STAI (state and trait) compared to the BP- group. In logistic regression analysis, depression in MMPI, self-directedness in TCI, and age were negatively associated with MDQ score, meanwhile, Ma in MMPI and STAI (trait) were positively associated with MDQ score. CONCLUSION The result of this study suggests that almost 50% of patients with panic disorder are likely to have hypomanic or manic symptoms, and certain psychological factors are associated bipolarity in panic disorder.