When one stops Zoloft too rapidly discontinuation syndrome may develop. Among the symptoms that may be experienced are nausea, tremors, lightheadedness, muscle pains, weakness, insomnia, and anxiety. While most people coming off Zoloft have none of these symptoms, some people do have one or more. The symptoms usually last 1-2 weeks; but, in some instances, they may gradually decrease over a period as long as a month. It is generally recommended that one taper off this medication gradually under a doctor's supervision. Check with your own personal physician for specific instructions.