In patients with comorbid substance use disorder and BP-II, episodes have a longer duration and treatment compliance decreases. Preliminary studies suggest that comorbid substance use is also linked to increased risk of suicidality. Diagnosis
BP-II is diagnosed according to the criteria established in the American Psychiatric Associations Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5). In addition, alternative diagnostic criteria is established in the World Health Organizations International Classification of Diseases-10th Revision (ICD-10). The diagnostic criteria are established from self-reported experiences from patients or their family members, the psychiatric assessment, and the mental status examination. In addition, Screening instruments like the Mood Disorders Questionnaire are helpful tools in determining a patients status on the bipolar spectrum. In addition, certain features have been shown to increase the chances that depressed patients have a bipolar disorder, including atypical symptoms of depression like hypersomnia and hyperphagia, a family history of bipolar disorder, medication-induced hypomania, recurrent or psychotic depression, antidepressant refractory depression, and early or postpartum depression. DSM-5 criteria
According to the DSM-5, a patient diagnosed with BP-II will have experienced at least one hypomanic episode, at least one major depressive episodes, and no manic episode. Furthermore, the occurrence of the mood episodes are not better explained by schizoaffective disorder, schizophrenia, delusional disorder, or other specified or unspecified schizophrenia spectrum and other psychotic disorder.
In his paper, Jung introduced the non-psychotic version of the illness with the statement, "I would like to publish a number of cases whose peculiarity consists in chronic hypomanic behavior" where "it is not a question of real mania at all but of a hypomanic state which cannot be regarded as psychotic." Jung illustrated the hypomanic variation with five case histories, each involving hypomanic behavior, occasional bouts of depression, and mixed mood states, which involved personal and interpersonal upheaval for each patient.In 1975, Jungs original distinction between mania and hypomania gained support. Fieve and Dunner published an article recognizing that only individuals in a manic state require hospitalization. It was proposed that the presentation of either the one state or the other differentiates two distinct diseases; the proposition was initially met with skepticism. However, studies since confirm that BP-II is a phenomenologically distinct disorder.Empirical evidence, combined with treatment considerations, led the DSM-IV Mood Disorders Work Group to add BP-II as its own entity in the 1994 publication. Only one other mood disorder was added to this edition, indicating the conservative nature of the DSM-IV work group. In May 2013, the DSM-5 was released. Two revisions to the existing BP-II criteria are anticipated. The first expected change will reduce the required duration of a hypomanic state from four to two days. The second change will allow hypomania to be diagnosed without the manifestation of elevated mood; that is, increased energy/activity will be sufficient.