Evidence from genetic research, monoamine studies and psychopharmacological trials points towards a possible biological predisposition and precipitant for suicidal behaviour. The implications for early detection and management based on a biological model have been discussed. The limitations of the model have been discussed.

Nicotine, the main addictive component of tobacco, activates and desensitizes nicotinic acetylcholine receptors (nAChRs). In that way, nicotine alters normal nicotinic cholinergic functions. Among the myriad of psychopharmacological effects that underlie the addiction process, nicotine influences nAChR participation in synaptic plasticity. This influence has particular importance in the mesocor...