BackgroundCholesterol plays an important part in cellular structure and function and changes in serum levels may affect neurotransmission in the central nervous system.MethodA medline literature search was made covering the period 1990–95 with systematic searching of citations from the articles identified. Representative articles were selected, focusing on those aspects which had not been thoroughly reviewed elsewhere, namely suicidal ideation, depression, personality and schizophrenia.ResultsLowering cholesterol levels have been associated with an increase in violent deaths in cardiovascular primary prevention studies. However, altered cholesterol levels have also been reported in relation to other psychiatric disorders.ConclusionThere is substantial evidence that serum cholesterol levels may be associated with variations in mental state or personality. Further work is needed to clarify this and to elucidate the mechanisms involved.