The new Bipolar Spectrum.
“There is growing clinical and epidemiologic evidence that major mood disorders form a spectrum from major depressive disorder to pure mania.”
Subthreshold mania can be seen as a precursor to Bipolar Disorder, subthreshold Bipolar Disorder is defined as “recurrent hypomania without a major depressive episode or with fewer symptoms than required for threshold hypomania” (Merikangas et al, 2007). Bipolar disorder should be suspected if prominent behavior problems, anxiety, and substance abuse were present during childhood in someone with recurrent depression and a family history of affective disorders. For example, the prevalence of anxiety in children may be prominent in early-onset Bipolar Disorder and may predate affective symptoms. Children with a parent with Bipolar Disorder are more likely to be at risk for early-onset Bipolar Disorder, along with anxiety, depression and other disorders.
Studies have shown that offspring of people with Bipolar Disorder are at high risk for developing Bipolar Disorder because they have a parent with the disorder and generally have significantly higher rates of subthreshold mania or hypomania (13.3% versus 1.2%) or what is known as bipolar disorder not otherwise specified (BP-NOS); manic, mixed, or hypomanic episodes (9.2% versus 0.8%); major depressive episodes (32.0% versus 14.9%); and anxiety disorders (39.9% versus 21.8%) than offspring of parents without the disorder. Subthreshold episodes of mania or hypomania (those that resemble but do not meet the full requirements for bipolar disorder in terms of duration) were the best predictor of later manic episodes.
It should be noted that the American Journal of Psychiatry has a multitude of studies that suggest that people who suffer from Major Depressive Disorder (MDD) have a higher susceptibility to Bipolar Disorder and that subthreshold hypomanic symptoms that are found in people suffering from MDD should be taken into consideration when diagnosing. Placing these people instead on a bipolar spectrum, hence altering their treatment plan by incorporating a mood stabiliser which can also assist with the present MDD.