Hopefully this will help and it's what you are looking for.
Answer:
increase anxiety; decreased vulnerability to overreact to stress
Explanation:
Serotonin (5-HT) is a natural neurotransmitter that carries signals between nerve cells (neurons) throughout the body. This neurotransmitter (serotonin) is responsible for regulating many biological functions (e.g., mood, digestion, sleep, etc). Moreover, it has been shown that there is an association between low cerebrospinal fluid 5-hydroxyindole-acetic acid (5-HIAA, the principal serotonin metabolite in the brain) levels and the risk of developing depression or destructive behaviors. In addition, serotonin concentration can also be elevated in situations of anxiety and/or stress. Antidepressants such as Prozac, Zoloft and Paxil act as serotonin uptake inhibitors that increase serotonin concentration at the synaptic site. Like other drugs, these antidepressants may lead to increase anxiety and decrease the vulnerability to react to stress by downregulating sensitivity to serotonin released during natural stress situations.
