Treatment of Mood Disorders: Renal Disease
It is unclear whether psychiatric illness or specific mood disorders are related to renal disease or to the psychological distress associated with dialysis and the intensity of services required by many of these patients. In addition, it still remains poorly understood whether the high degree of noncompliance within this population is due to, or a result of, this comorbidity. Unlike several diseases already mentioned, renal disease and the subsequent onset of renal failure have many causes. These include hypertension, diabetes mellitus, coronary artery disease, and immunological and rheumatological illnesses such as lupus erythematosus. Psychiatric illness in patients with renal disease is more frequently diagnosed while the patient is hospitalized than it is for patients with many other medical illnesses. A recent study has shown that almost 9% of all dialysis patients studied required psychiatric hospitalization. Hospitalization with a psychiatric disorder was estimated to be 1 to 3 times as frequent for patients with renal failure compared with patients with other chronic illnesses including diabetes, ischemic heart disease, cerebrovascular disease, and peptic ulcer disease. Comorbidity of mood disorders is estimated to be between 5% and 20%, but a subanalysis of diabetes mellitus, rheumatoid arthritis, or other medical illnesses has not yet been done in patients with renal disease. The complexity of such a study probably prohibits its undertaking.

Information concerning characteristics associated with dialysis and premature death has been analyzed, revealing older age, white race, physical and nutritional impairment, history of MI, congestive heart failure, and clinical depression to be significant factors. The major therapeutic issue in treatment surrounds the safety and efficacy of the antidepressant used. Virtually all antidepressants may be used in renal failure, including the TCAs, as long as serum levels of the primary drug and its hydroxylated metabolites are closely monitored. The pharmacokinetics of fluoxetine and its active metabolite norfluoxetine have not been found to be meaningfully affected in patients with mild, moderate, or severe renal dysfunction. Further research examined the steady-state plasma concentration of fluoxetine and norfluoxetine in dialysis patients. Using 20 mg of fluoxetine, steady-state plasma concentrations of the sum of fluoxetine and its metabolite were comparable to those of patients with normal renal function. Efficacy was noted with the use of fluoxetine, but the study was very small, so the validity could be nonsignificant.