The authors review some of the noradrenergic studies in suicide, including studies of the biosynthetic enzyme for norepinephrine, tyrosine hydroxylase, the receptors for norepinephrine, alpha- & beta-adrenergic receptors, as well as the signaling cascades linked to beta-adrenergic receptors. In general, these studies indicate the protein expression of tryosine hydroxylase, as well as alpha2- & beta2-adrenergic receptors, is increased in the postmortem brain of suicide victims. More studies are needed in order to examine extensively the role of noradrenergic function in suicidal behaviour. (76 refs.)