Evolving methodologies in bipolar disorder maintenance research.

BACKGROUND

During the development of a new treatment for bipolar disorder, maintenance studies are used to evaluate the ability of the putative mood stabilizer to prevent relapse and recurrence of further episodes. Comparisons with the early bipolar disorder maintenance studies indicate that the methodologies of recent trials have evolved substantially.

AIMS

To review the methods used in the first- and second-generation maintenance studies, highlighting the differences of the various designs.

METHOD

Literature review.

RESULTS

Methods that have evolved the most include patient enrollment, randomisation schemes and the use of outcome measures and statistical analyses. In addition, regulatory and commercial issues have also influenced study design.

CONCLUSION

There is little consensus on the methodology of bipolar disorder maintenance studies. As the integration of newer therapies into routine clinical practice is dependent on the evidence from controlled studies, it is essential that future maintenance trials in bipolar disorder achieve adequate methodological rigour without sacrificing overall feasibility.