Lipids, Hormones, and Gastric Bypass

To the Editor: I read with great interest the case presentation by Wei Jiang, M.D., and colleagues on psychosis after gastric bypass surgery (1) . As a member of the house staff at their institution, I briefly assisted in the care of the patient and recall him as among the more acutely psychiatrically ill patients I have seen. Outside of the discussed concerns, additional questions were raised in regard to this case. I present the following two related points as worthy of further discussion.

First, brain tissue is composed largely of lipids (2) . Although we know the effect of rapid weight loss on serum lipids and adipose tissue (3, 4), I am unaware of reports on the effects of bariatric surgeries and subsequent rapid weight loss on nervous tissue, especially in the central nervous system (CNS).

Second, adipose tissue is highly involved in many areas of steroid metabolism and other endocrine processes (5, 6), which also affect psychiatric illness and behavior. In addition, bariatric surgery is responsible for direct changes in hormones (7, 8), but there are few studies investigating its potential impact on the CNS.

Gastric bypass surgery is generally relatively well tolerated, and many of the changes result in improvements in general health, but we know little about the effect on psychiatric illness and behavior (9, 10) . It is conceivable that the processes mentioned above may also have adversely affected the patient in the study by Dr. Jiang and colleagues, and these processes warrant further research.