Traditionally high cholesterol is known to be harmful, now a recent study has found that too low cholesterol is associated with adverse behavioural effects such as aggression and depression. Researchers from Yale University School of Medicine studied 25 violent psychiatric patients. For 7 days, the patients wore signalling devices that emitted an average of seven signals a day. Following each signal, patients filled out a mood questionnaire. The authors found that "Total serum cholesterol (TSC) concentration was positively associated with measures of affect, cognitive efficiency, activation, and sociability, suggesting a link between low TSC and dysphoria." "These findings are consistent with the cholesterol-serotonin hypothesis (Kaplan, Psychosom Med 1994 Nov-Dec;56:479-84) and with the substantive literature linking both aggression and depression to depressed central serotonergic activity," the researchers concluded. Full findings are published in the Journal of Behavioral Medicine, December 1, 2000; 23: 519-529
