According to the National Alliance on Mental Illness, people usually notice improvements in sleep, energy and appetite within the first one to two weeks of taking Zoloft. Improvements in mood often take up to six to eight weeks to be noticed.
The NAMI says that Zoloft is used for the treatment of depression, among other things. Symptoms of depression include feeling worthless or sad, sleeping more or less than normal, lack of interest in activities that used to bring joy, and low energy. The side effects of taking Zoloft include headaches, dry mouth, increased sweating, trouble sleeping, problems with orgasm and ejaculation, diarrhea, confusion, seizures and death. Zoloft often leads to having low sodium blood levels, which makes it difficult to remember things and to concentrate.