How does celexa (citalopram) work to make you feel better, it helped my panic attacks by 90 percent but how?

Chemical balance: Celexa is a brand name for citalopram which is a member of the ssri (selective serotonin reuptake inhibitor) class. They work by decreasing the absorption of serotonin, thus allowing it to stick around a bit longer to continue signaling. Thus, ssris work to balance out neurotransmitter imbalance, which is felt by many to be cause of depression, anxiety, panic attacks & other mood disorders.