Are there psychiatric medications that have an anti-tolerance effect? Patients usually develop tolerance to their psychiatric medications when used over a long period of time. This is because of how the brain gets used to the dosage in order to reach equilibrium again. Are there any that have an anti-tolerance effect? Which means over time you would need less and less of the medication to get the same effect?
I don't know of any drug therapy that becomes less with use, especially for treatment of psychological disorders. The only instance I would know of is an individual is attempting to remove a medication to try something new/ different. The basic reasoning is described below. 

There is an understanding of the pharmacodynamics of how the drugs or medications are believed to behave when interacting with the brain. Receptor cites can also be a factor, and will depend on if the medication is believed to be an agonistic action, or an antagonistic action (does it block receptors from uptake, or does it increase?). Either way, the neurobiology of the brain at the synapse of the neurotransmitter is believed to change, and the amount of certain chemicals could change as well.

Another few contributing factors would be how the therapeutic range for the medication is thought of by the pharmacological community, or how much dosage an individual needs for the medication to be therapeutic. Anyone that has been on a medication longer-term might experience withdraw effects when reducing the medication because the brain isn't able to take over production of the "needed" neurotransmitters. A half-life discusses how long the drug will remain in the body, and at what point it might stop the therapeutic range, which is why some dosing is over several ingestion cycles verses an extended release. 

I highly recommend the book "A Primer of Drug Action" by Julien, Adcokat and Comaty (2011) for further reading. It describes a lot of medications and drugs. There are a variety of understandings of these medications and drugs currently.