Using comparative effectiveness design to improve the generalizability of bipolar treatment trials data: contrasting LiTMUS baseline data with pre-existing placebo controlled trials

BACKGROUND

Efficacy-based double-blind placebo controlled trials were conducted to establish efficacy and safety for FDA approval. Such designs allowed and encouraged the use of exclusion criteria to improve assay sensitivity and internal validity. The LiTMUS trial increased the representation of real-world individuals with bipolar disorder despite the acknowledgment that this compromises assay sensitivity.

METHOD

To maximize generalizability, LiTMUS used broad inclusion and narrow exclusion criteria: participants experiencing mood symptoms of sufficient intensity (at least with a CGI-BP ≥ 3) that would warrant a change in treatment, and that lithium treatment would be a reasonable therapeutic option if they were randomized to it. At baseline demographic, illness, clinical, and treatment characteristics were collected. The LiTMUS study design and baseline sociodemographic data were compared to previous efficacy studies.

RESULTS

As compared to the previous bipolar disorder efficacy studies, LiTMUS participants were of similar age, gender, weight and illness severity; however LiTMUS participants were more racially and ethnically representative of the general population, had a greater number of mood episodes in the past 12 months, more Axis I/II comorbidity, a greater number of prior suicide attempts, and higher functional capacity.

CONCLUSIONS

LiTMUS was a comparative effectiveness trial that had broad inclusion and minimal exclusion criteria that produced a more representative sample comprised of real-world participants. This design enables the results of the LiTMUS study to be a more representative of real world pharmacotherapuetic outcomes.

LIMITATIONS

Limitations include possible selection bias, paucity of sociodemographic data in efficacy trials, and lack of a placebo.

Aims and results of the NIMH systematic treatment enhancement program for bipolar disorder (STEP-BD)

The Systematic Treatment Enhancement Program for Bipolar Disorder (STEP-BD) was funded as part of a National Institute of Mental Health initiative to develop effectiveness information about treatments, illness course, and assessment strategies for severe mental disorders. STEP-BD studies were planned to be generalizable both to the research knowledge base for bipolar disorder and to clinical care of bipolar patients. Several novel methodologies were developed to aid in illness characterization, and were combined with existing scales on function, quality of life, illness burden, adherence, adverse effects, and temperament to yield a comprehensive data set. The methods integrated naturalistic treatment and randomized clinical trials, which a portion of STEP-BD participants participated. All investigators and other researchers in this multisite program were trained in a collaborative care model with the objective of retaining a high percentage of enrollees for several years. Articles from STEP-BD have yielded evidence on risk factors impacting outcomes, suicidality, functional status, recovery, relapse, and caretaker burden. The findings from these studies brought into question the widely practiced use of antidepressants in bipolar depression as well as substantiated the poorly responsive course of bipolar depression despite use of combination strategies. In particular, large studies on the characteristics and course of bipolar depression (the more pervasive pole of the illness), and the outcomes of treatments concluded that adjunctive psychosocial treatments but not adjunctive antidepressants yielded outcomes superior to those achieved with mood stabilizers alone. The majority of patients with bipolar depression concurrently had clinically significant manic symptoms. Anxiety, smoking, and early age of bipolar onset were each associated with increased illness burden. STEP-BD has established procedures that are relevant to future collaborative research programs aimed at the systematic study of the complex, intrinsically important elements of bipolar disorders.

Prospective 12-month course of bipolar disorder in out-patients with and without comorbid anxiety disorders

BACKGROUND

The impact of anxiety disorders has not been well delineated in prospective studies of bipolar disorder.

AIMS

To examine the association between anxiety and course of bipolar disorder, as defined by mood episodes, quality of life and role functioning.

METHOD

A thousand thousand out-patients with bipolar disorder were followed prospectively for 1 year.

RESULTS

A current comorbid anxiety disorder (present in 31.9% of participants) was associated with fewer days well, a lower likelihood of timely recovery from depression, risk of earlier relapse, lower quality of life and diminished role function over I year of prospective study. The negative impact was greater with multiple anxiety disorders.

CONCLUSIONS

Anxiety disorders, including those present during relative euthymia, predicted a poorer bipolar course. The detrimental effects of anxiety were not simply a feature of mood state. Treatment studies targeting anxiety disorders will help to clarify the nature of the impact of anxiety on bipolar course.

Cognitive styles and life events interact to predict bipolar and unipolar symptomatology

This study examined the interaction of cognitive style (as assessed self-report and information-processing battery) and stressful life events in predicting the clinician-rated depressive and manic symptomatology of participants with Research Diagnostic Criteria lifetime diagnoses of bipolar disorder (n = 49), unipolar depression (n = 97), or no lifetime diagnosis (n = 23). Bipolar and unipolar participants' attributional styles, dysfunctional attitudes, and negative self-referent information processing as assessed at Time 1 interacted significantly with the number of negative life events that occurred between Times 1 and 2 to predict increases in depressive symptoms from Time 1 to Time 2. Within the bipolar group, participants' Time 1 attributional styles and dysfunctional attitudes interacted significantly, and their self-referent information processing interacted marginally, with intervening life events to predict increases in manic symptoms from Time 1 to Time 2. These findings provide support for the applicability of cognitive vulnerability-stress theories of depression to bipolar spectrum disorders.

Cognitive styles and life events interact to predict bipolar and unipolar symptomatology

This study examined the interaction of cognitive style (as assessed self-report and information-processing battery) and stressful life events in predicting the clinician-rated depressive and manic symptomatology of participants with Research Diagnostic Criteria lifetime diagnoses of bipolar disorder (n = 49), unipolar depression (n = 97), or no lifetime diagnosis (n = 23). Bipolar and unipolar participants' attributional styles, dysfunctional attitudes, and negative self-referent information processing as assessed at Time 1 interacted significantly with the number of negative life events that occurred between Times 1 and 2 to predict increases in depressive symptoms from Time 1 to Time 2. Within the bipolar group, participants' Time 1 attributional styles and dysfunctional attitudes interacted significantly, and their self-referent information processing interacted marginally, with intervening life events to predict increases in manic symptoms from Time 1 to Time 2. These findings provide support for the applicability of cognitive vulnerability-stress theories of depression to bipolar spectrum disorders.