Sorry, I was wrong.
It is known that amphetamine and methamphetamine cause their stimulant effect by inducing the release of dopamine in neuron in certain regions of the brain. 4-substituted amphetamines has been shown to possess different pharmacological properties than the unsubstituted analog. It has been shown that 4-haloamphetamines in addition to their effect on dopamine also expresses serotonin-releasing effects, causing a long-term depletion of serotonin, indicating a neurotoxic effect, much like the one suggested to occur with MDMA and some of its derivatives. However, among the 4-haloamphetamines, the fluoro analog seemed to be atypical in that it did not cause any long-term changes in the brain serotonin levels, even though it was also a serotonin-releasing agent like the other 4-haloamphetamines, although weaker than the other.