Mental Illness Comorbidity & Treatment

Comorbidity refers to the existence of two or more diseases in the same patient. Although exact statistics regarding the presence of comorbidity in people with mental illness are not available, comorbidity is known to be a serious problem. For example, many people with mental disorders have comorbid substance-related disorders, in which they abuse substances such as cigarettes and alcohol. Many patients with schizophrenia also abuse illegal drugs such as cocaine. The reasons for such behavior may include attempts to improve social skills or attempts to alleviate symptoms through “self-medication.” The resulting behaviors related to their drug use and drug seeking, such as theft, overdose, infection, and lack of nutrition, can complicate all aspects of treatment.

The most common comorbid psychiatric disorders seen with serious mental disorders such as schizophrenia are depression, anxiety disorders, obsessive-compulsive disorder, and substance abuse. Because each of these conditions requires different treatment approaches, physicians and other health care providers often face the challenge of ensuring that they are treating one disorder without worsening the other disorder(s) or affecting overall treatment. In the past, many physicians focused first on a patient’s most severe problem, waiting until it improved before addressing the comorbid illness. However, this approach often backfired when the untreated disorder worsened in the meantime. Thus, the philosophy today is to simultaneously address all comorbid illnesses. The drawback of this approach is that patients taking multiple medications for comorbid conditions are at increased risk for drug interactions and serious side effects.