Schizophrenia and bipolar disorder overlap considerably in terms of symptoms, familial patterns, risk
genes, outcome, and treatment response. This article provides an overview of the specificity and continuity of
schizophrenia and mood disorders on the basis of biomarkers, such as genes, molecules, cells, circuits, physiology
and clinical phenomenology. Overall, the discussions herein provided support for the view that schizophrenia,
schizoaffective disorder and bipolar disorder are in the continuum of severity of impairment, with bipolar disorder
closer to normality and schizophrenia at the most severe end. This approach is based on the concept that examining
biomarkers in several modalities across these diseases from the dimensional perspective would be meaningful.
These considerations are expected to help develop new treatments for unmet needs, such as cognitive dysfunction,
in psychiatric conditions.