If you have been suffering from the symptoms of depression, anxiety or obsessive compuslive disorder, then perhaps it What is metronidazole prescribed for time to consider a change in medication. The drug Zoloft may be right for you. Zoloft (sertraline HCL) works to increase the levels of serotonin in your brain by inhibiting its breakdown. It does this by altering the amount of neurotransmitters present in your synapse. This can help you to regain control over emotions and thoughts by putting them back into balance.