The combination of psychotherapy and L-Dopa medication may prove more effective at helping those suffering from phobias or PTSD by keeping their fear associations at bay for longer.
Breaking this statement down, psychotherapy is any therapy using non-medical ways to treat someone. It's using psychological means, such as cognitive behavioral therapy, to get to the end goal. For something like a spider phobia, you desensitize a patient by showing them pictures or movies of non-scary spiders (Itsy) and gradually building it up to, say, a tarantula. As they view these images and engage with them, nothing bad happens to them, and the patient learns not to associate spiders, the stimulus, with fear. It's about re-teaching the brain to think about something in a different way. The same can be applied to soldiers off to war. Before going to war, a study had soldiers practice fear extinction in the laboratory and those who were able to extinguish their fear maintained a good state of mental health during war, as opposed to others who later developed PTSD. As Professor Raffael Kalish, head of the Neuroimaging Center of the JGU Translational Neurosciences Research Center, said, "If you are mentally flexible enough to change the associations that your mind has created, you might be better able to avoid lasting damage." Fear is a good thing, and has kept us alive all these generations. However, memories of something causing you pain can lead into a long-term anxiety or phobia. Therefore, psychotherapy is extremely important to keep us mentally healthy. Where does L-Dopa come into this?
L-Dopa is a chemical made naturally in humans, and many animals and plants. It is the precursor to the neurotransmitters dopamine, norepinephrine, and epinephrine (adrenaline) in our brains. It controls the brain's reward and pleasure centers, helps regulate movement, and can affect memory formation. However, it can also be made in a laboratory and prescribed as a psychoactive drug. It is usually prescribed to patients suffering from Parkinson's Disease. Applying it to phobias and PTSD, the combination of psychotherapy and L-Dopa may help stop relapses after successful therapy. Even after successful extinction, old fear associations may return under other stressful circumstances. Because of L-Dopa's ability to affect memory formation, using it will help create a stronger secondary positive memory of not having the phobia or PTSD. Basically, after overcoming your fear or anxiety, you will receive the drug, which will make you happy. You will remember how happy you felt when you achieved this, reinforcing the idea that not being scared of that stimulus is a really good thing. When you perform behavior therapy you create a competing memory to the fear memory you have of the stimulus. Post-extinction administration of L-Dopa will make those competing memories more context-independent, therefore strongly reducing the return of you fear. Any memory with emotion will be more prominent, so adding L-Dopa will boost the importance of the memory and will do so in a positive light.