of an agent useful in preventing or inhibiting the cocaine addiction related behavior in yet another embodiment a method for identifying an agent to be tested for an abiity to prevent or inhibit cocaine addiction related behavior is provided which comprises a obtaining a brain tissue sample from each of a subject having a cocaine addiction related behavior and a cocaine addiction free subject b detecting a level of expression of at least one gene in both tissue samples wherein the gene encodes a polypeptide selected from the group consisting of gaba b receptor subunit gb2 cell adhesion like molecule bos taurus like neuronal axonal protein similar to mouse chemokine like factor fra 2 similar to human oxygen regulated protein similar to mouse mrg1 protein pentraxin malic enzyme olfactomedin related protein arc growth factor enriched in dendrites protein tyrosine phosphatase krox neuritin microtubule associated protein 2d and cb1 cannabinoid receptor c subtracting the level of expression of the gene in the sample obtained from the cocaine addiction free subject from the level of expression of the gene in the sample obtained from the subject having cocaine addiction related behavior to provide a first value d administering a candidate agent to each of a subject having a.