According to WebMD, withdrawal symptoms from Celexa and other similar antidepressants often take one to two weeks to dissipate. These symptoms usually occur within three days following the stopping of treatment.
WebMD describes the common symptoms of antidepressant withdrawal as mild. They include anxiety, irritability and depression, among others. Antidepressant withdrawal can cause mania in those who are suffering from bipolar disorder, although this reaction is rare. Immediately stopping treatment without first consulting a doctor is not recommended; instead, a more gradual approach is healthier and less likely to cause withdrawal symptoms. This process, called tapering, allows the brain to better adjust to chemical changes.