A variety of general medical conditions may cause mood symptoms. These conditions include degenerative neurological conditions (e.g., Parkinson’s disease, Huntington’s disease), cerebrovascular disease (e.g., stroke), metabolic conditions (e.g., vitamin B12 deficiency), endocrine conditions (e.g., hyper- and hypothyroidism, hyper- and hypoparathyroidism, hyper- and hypoadrenocorticism), autoimmune conditions (e.g., systemic lupus erythematosus), viral or other infections (e.g., hepatitis, mononucleosis, human immunodeficiency virus [HIV]), and certain cancers (e.g., carcinoma of the pancreas). The associated physical examination findings, laboratory findings, and patterns of prevalence or onset reflect the etiological general medical condition.
Prevalence estimates for Mood Disorder Due to a General Medical Condition are confined to those presentations with depressive features. It has been observed that 25%-40% of individuals with certain neurological conditions (including Parkinson’s disease, Huntington’s disease, multiple sclerosis, stroke, and Alzheimer’s disease) will develop a marked depressive disturbance at some point during the course of the illness. For general medical conditions without direct central nervous system involvement, rates are far more variable, ranging from more than 60% in Cushing’s syndrome to less than 8% in end-stage renal disease.