Etiology (i.e., a causal relationship to another medical condition based on best clinical ev- idence) is the key variable in this etiologically specified form of bipolar disorder. The list- ing of medical conditions that are said to be able to induce mania is never complete, and the clinician’s best judgment is the essence of this diagnosis. Among the best known of the medical conditions that can cause a bipolar manic or hypomanic condition are Cushing's disease and multiple sclerosis, as well as stroke and traumatic brain injuries.
Bipolar and related disorder due to another medical condition usually has its onset acutely or subacutely within the first weeks or month of the onset of the associated medical con- dition. However, this is not always the case, as a worsening or later relapse of the associ- ated medical condition may precede the onset of the manic or hypomanic syndrome. The clinician must make a clinical judgment in these situations about whether the medical con- dition is causative, based on temporal sequence as well as plausibility of a causal relation-
Bipolar and Related Disorder Due to Another Medical Condition 147 ship. Finally, the condition may remit before or just after the medical condition remits, particularly when treatment of the manic/hypomanic symptoms is effective.
Culture-related differences, to the extent that there is any evidence, pertain to those asso- ciated with the medical condition (e.g., rates of multiple sclerosis and stroke vary around the world based on dietary, genetic factors, and other environmental factors).
Gender differences pertain to those associated with the medical condition (e.g., systemic lupus erythematosus is more common in females; stroke is somewhat more common in middle-age males compared with females).
Diagnostic markers pertain to those associated with the medical condition (e.g., steroid levels in blood or urine to help corroborate the diagnosis of Cushing’s disease, which can be associated with manic or depressive syndromes; laboratory tests confirming the diag- nosis of multiple sclerosis).
Functional Consequences of Bipolar and Related
Disorder Due to Another Medical Condition
Functional consequences of the bipolar symptoms may exacerbate impairments associ- ated with the medical condition and may incur worse outcomes due to interference with medical treatment. In general, it is believed, but not established, that the illness, when in— duced by Cushing’s disease, will not recur if the Cushing’s disease is cured or arrested.
However, it is also suggested, but not established, that mood syndromes, including de- pressive and manic/hypomanic ones, may be episodic (i.e., recurring) with static brain in- juries and other central nervous system diseases.
Symptoms of delirium, catatonia, and acute anxiety. It is important to differentiate symptoms of mania from excited or hypervigilant delirious symptoms; from excited cata- tonic symptoms; and from agitation related to acute anxiety states.
Medication-induced depressive or manic symptoms. An important differential diag- nostic observation is that the other medical condition may be treated with medications (e.g., steroids or alpha-interferon) that can induce depressive or manic symptoms. In these cases, clinical judgment using all of the evidence in hand is the best way to try to separate the most likely and/ or the most important of two etiological factors (i.e., association with the medical condition vs. a substance/medication~induced syndrome). The differential di— agnosis of the associated medical conditions is relevant but largely beyond the scope of the present manual.
Conditions comorbid with bipolar and related disorder due to another medical condition are those associated with the medical conditions of etiological relevance. Delirium can oc- cur before or along with manic symptoms in individuals with Cushing’s disease.
296.89 (F31.89)