What do a tardive dyskinesia patient's low levels of dopamine mean when it comes to sex? Why is sex so beneficial to the treatment?First we should examine again that tardive dyskinesia is a disorder that has low levels of dopamine receptors, what dopamine is, and how sex as a treatment helps tardive dyskinesia symptoms.
What is dopamine? Dopamine is one of the chemical signals that pass information from one neuron to the next in the tiny spaces between them. When it is released from the first neuron, it floats into the space (the synapse) between the two neurons, and it bumps against receptors for it on the other side that then send a signal down the receiving neuron. That sounds very simple, but when you scale it up from a single pair of neurons to the vast networks in your brain, it quickly becomes complex. The effects of dopamine release depend on where it’s coming from, where the receiving neurons are going and what type of neurons they are, what receptors are binding the dopamine (there are five known types), and what role both the releasing and receiving neurons are playing. [source]
Dopamine receptors are typically stable, however sharp (and sometimes prolonged) increases or decreases in dopamine levels (via stimulants or antipsychotics mainly) can downregulate (reduce the numbers of) or upregulate (increase the numbers of) dopamine receptors.
For example, dopamine plays a big role in starting movement, and the destruction of dopamine neurons in an area of the brain called the substantia nigra is what produces the symptoms of Parkinson’s disease (a sister of Tardive Dyskinesia). Dopamine also plays an important role as a hormone, inhibiting prolactin to stop the release of breast milk. Back in the mesolimbic pathway, dopamine can play a role in psychosis, and many antipsychotics for treatment of schizophrenia target dopamine. Dopamine is involved in the frontal cortex inexecutive functions like attention. In the rest of the body, dopamine is involved in nausea, in kidney function, and in heart function.
So dopamine has to do with addiction, whether to cupcakes or cocaine. It has to do with lust and love. It has to do with milk. It has to do with movement, motivation, attention, psychosis. Dopamine plays a role in all of these. But it is none of them, and we shouldn’t want it to be. Its complexity is what makes it great. It shows us what, with a single molecule, the brain can do. [Source]
After orgasm, the body increases prolactin which counteracts dopamine. Prolactin provides the body with sexual gratification after sexual acts: The hormone counteracts the effect of dopamine, which is responsible for sexual arousal. This is thought to cause the sexual refractory period. The amount of prolactin can be an indicator for the amount of sexual satisfaction and relaxation.
One study examined 12 healthy women using a positron emission tomography (PET) scanner while they were being stimulated by their partners. Brain changes were observed and compared between states of rest, sexual stimulation, faked orgasm, and actual orgasm. "Differences were reported on the brain changes associated with men and women during stimulation. However, the same changes in brain activity were observed in both sexes in which the brain regions associated with behavioral control, fear and anxiety shut down. Regarding these changes, Holstege said in an interview with The Times, "What this means is that deactivation, letting go of all fear and anxiety, might be the most important thing, even necessary, to have an orgasm." [source]
Conclusion: Sex is very important to the treatment of Tardive Dyskinesia. It helps by shutting down the dopamine receptors and increasing the prolactin which de-stresses the body thereby helping with symptom control.