Researchers also reported that the new compounds bind the serotonin transporter with potencies similar to Prozac and other antidepressants.

Madras said she thinks the new compounds will do more than just bind to the target; they will actually affect the function as well.

The experimental compounds blocked dopamine transport in experiments with cell cultures, according to the study.

Preliminary tests with living animals also indicated that the compounds produce bio-chemical and behavioral affects comparable to those of other dopamine transporter blockers.

Researchers can benefit from her data, Madras suggests, because it is unnecessary for drugs to act in the same way as neuro-transmitters.

Neurotransmitters cross the synaptic gaps in the brain in milliseconds, stimulate the neuron on the other side and are then metabolized quickly.

Nitrogen is necessary to give neurotransmitters the ability to carry out these steps.

But drugs do not have to act in the same way and a slower mode of action might lead to a longer-lasting drug that would prevent the patient from having to take medicine every few hours.

According to Madras, the results suggest that there may be a different mechanism by which drugs recognize targets in the brain that had previously been overlooked.

Previous assumptions operated under the theory that the nitrogen atom forms a strong ionic bond with a counterion on the brain's target molecule.

However, the new results suggest that the experimental drugs, and possibly other compounds as well, bind to transporters by aligning the fatty parts of their structure with similar fatty components on the transporter through what is known as molecular stacking interaction.

Madras said the potential of the new drugs is unclear because much work remains to study the toxicology and pharmacology of the new compounds.

"I feel that we opened a small window in a dark house and see that there is a whole new vista," Madras said in the statement "And now, let's walk and see how far that takes us."