Although No-Type I Bipolar spectrum disorders (NBP-I) are common, recurrent, and disabling, they are
underdiagnosed and misdiagnosed in clinical practice. Several data show that NBP-I (especially BP type II) are a
significant public health problem, and there is a dearth of studies of effective treatment modalities for the control of acute
symptoms and the prevention of mood recurrences (mainly major depressive episodes). Considering the growing need to
find effective therapies for patients with NBP-I, this review is based on a systematic search of evidence about the efficacy
of treatments for each phase of the NBP-I.
Fifty-seven studies were identified and reviewed. Most studies investigating the pharmacotherapy of NBP-I were
methodologically limited, having observational or retrospective designs and small samples. Regarding short-term
treatment, there is some limited support for the use of risperidone, valproate, and quetiapine in hypomania, and for
valproate, quetiapine, fluoxetine, and venlafaxine in treating depression. For long-term treatment, the only preventive
therapy for both depression and hypomania that is supported by several controlled studies is quetiapine. Lithium and
fluoxetine have shown efficacy in delaying depressive recurrences. Although the adequate treatment for these patients
remains to be determined, mood stabilizers and some forms of psychotherapy may be useful for these patients.
We conclude that there is a paucity of sound evidence to guide clinicians in treating NBP-I patients. Although progress
has been made, more quality research is needed to delineate effective treatment strategies.