Manic symptoms and impulsivity during bipolar depressive episodes

A relationship between bipolar II disorder and borderline personality disorder?

BACKGROUND

The relationship between DSM-IV-TR borderline personality disorder (BPD) and bipolar disorders, especially bipolar II disorder (BP-II), is still unclear. Many recent reviews on this topic have come to opposite or different conclusions.

STUDY AIM

The aim was to test the association between hypomania symptoms and BPD traits, as hypomania is the defining feature of BP-II in DSM-IV-TR.

METHODS

During follow-up visits in a private practice, consecutive 138 remitted BP-II outpatients were re-diagnosed by a mood disorder specialist psychiatrist, using the Structured Clinical Interview for DSM-IV (as modified by Benazzi and Akiskal for better probing hypomania). Soon after, patients self-assessed (blind to interviewer) the SCID-II Personality Questionnaire for BPD. Associations and confounding were tested by logistic regression, between each criteria symptom of hypomania (apart from "racing thoughts" and "distractibility", not assessed as probing focused mainly on behavioral, observable signs), and the entire set of BPD traits. Multivariate regression was also used to jointly regress the entire set of hypomanic symptoms on the entire set of BPD traits.

RESULTS

Mean (SD) age was 39.0 (9.8) years, females were 76.3%. Frequency of BPD traits ranged between 17% and 66% (e.g. impulsivity trait 41%, affective instability trait 63%), mean (SD) number of traits was 4.2 (2.3). The most common episodic hypomanic symptoms were elevated mood (91%) and overactivity (93%); frequency of excessive risky, impulsive activities (impulsivity) was 62%. By logistic regression the only significant association was between the episodic impulsivity of hypomania and the trait impulsivity of BPD. Multivariate regression of the entire set of hypomanic symptoms jointly regressed on the entire set of BPD traits was not statistically significant.

DISCUSSION

The core feature of BP-II, i.e. hypomania, does not seem to have a close relationship with BDP traits in the study setting, partly running against a strong association between BPD and BP-II and a bipolar spectrum nature of BPD.

Impulsivity: differential relationship to depression and mania in bipolar disorder

INTRODUCTION

Impulsivity, a component of the initiation of action, may have a central role in the clinical biology of affective disorders. Impulsivity appears clearly to be related to mania. Despite its relationship to suicidal behavior, relationships between impulsivity and depression have been studied less than those with mania. Impulsivity is a complex construct, and it may be related differently to depression and to mania.

METHODS

In subjects with bipolar disorder, we investigated impulsivity in relationship to affective symptoms. Trait-like impulsivity was assessed with the Barratt Impulsiveness Scale (BIS-11). Affective symptoms were measured using the Change version of the Schedule for Affective Disorders and Schizophrenia (SADS-C). Measures were compared using analysis of variance, multiple regression and factor analysis.

RESULTS

Impulsivity, as measured by the BIS, was related differentially to measures of depression and mania. Total and attentional impulsivity correlated independently with depression and mania scores. Motor impulsivity correlated with mania scores, while nonplanning impulsivity correlated with depression scores. These relationships were strongest in subjects who had never met criteria for a substance use disorder. Among manic symptoms, visible hyperactivity correlated most strongly with BIS scores, regardless of clinical state. Among depressive symptoms, hopelessness, anhedonia, and suicidality correlated most strongly with BIS scores.

CONCLUSIONS

Depression and mania are differentially related to impulsivity. Impulsivity is related more strongly to measures of activity or motivation than to depressive or manic affect. The relationship between impulsivity and hopelessness may be an important factor in risk for suicide.

Validity and utility of bipolar spectrum models

The bipolar spectrum model suggests that several patient presentations not currently recognized by the DSM warrant consideration as part of a mood disorders continuum. These include hypomania or mania associated with antidepressants; manic symptoms which fall short of the current DSM threshold for hypomania; and depression attended by multiple non-manic markers that are associated with bipolar course. Evidence supporting the inclusion of these groups within the realm of bipolar disorder (BP) is examined. Several diagnostic tools for detecting and characterizing these patient groups are described. Finally, options for altering DSM-IV criteria to allow some of the above patient presentations to be recognized as bipolar are considered. More data on the validity and utility of these alterations would be useful, but limited changes appear warranted now. We describe an additional BP Not Otherwise Specified (BP NOS) example which creates a subthreshold hypomanic analogue to cyclothymia, consistent with existing BP NOS criteria. This change should be accompanied by additional requirements for the assessment and reporting of non-manic bipolar markers.

A tetrachoric factor analysis validation of mixed depression

BACKGROUND

Mixed depression, i.e. a Major Depressive Episode plus co-occurring manic/hypomanic symptoms, has recently become the focus of research. However, its diagnostic validity and bipolar nature are still not firmly supported. A bipolar nature could have significant treatment impacts.

STUDY AIM

The aim was to psychometrically validate the concept of, and the bipolar nature, of mixed depression, by using (for the first time) tetrachoric factor analysis of its hypomanic symptoms.

METHODS

Consecutive 441 Bipolar II Disorder (BP-II), and 289 Major Depressive Disorder (MDD) outpatients were cross-sectionally assessed for Major Depressive Episode (MDE) and concurrent hypomanic symptoms (as binary variables) when presenting for treatment of depression, by a mood disorder specialist psychiatrist (FB), using the Structured Clinical Interview for DSM-IV (as modified by [Akiskal HS, Benazzi F. Optimizing the detection of bipolar II disorder in outpatient private practice: toward a systematization of clinical diagnostic wisdom. J Clin Psychiatry 2005; 66: 914-921.]) in a private practice. Consecutive 275 remitted BP-II were also assessed for past hypomania. Mixed depression was defined as co-occurrence of MDE and 3 or more, usually subthreshold, hypomanic symptoms.

RESULTS

In multivariable logistic regression, BP-II independent predictor variables were young onset age, MDE recurrences, mixed depression, and bipolar family history. Factor analysis of past hypomania symptoms found three factors: an "irritable mental overactivity" factor, an "elevated mood" factor, and a "motor overactivity" factor. Factor analysis of intradepression hypomanic symptoms in BP-II, and in MDD, found two similar mental and motor overactivity factors. Multivariate regression of the intradepression hypomanic factors versus bipolar validators, such as bipolar family history and young onset age, found significant associations.

DISCUSSION

Findings could support the diagnostic validity, and the bipolar nature, of mixed depression, on the basis of the close similarities found between the factor structure of inter-depression hypomania and intra-depression hypomanic symptoms. Impacts on treatment of a bipolar nature of mixed depression may be significant (e.g. more use of mood stabilising agents, less/no use of antidepressants).