Multiple answers. Euphoria from zoloft (sertraline) is rare but possible. Serotonin stimulation can have a mini l.S.D. Effect&can cause excitation. Any antidepressant can induce mania. Dream enhancement from an ssri can seem euphoric. Early relief of depression can be interpreted as a good feeling. Interactions between zoloft (sertraline)&other prescription medications, herbal and nutritional agents &/or recreational drugs can fuel a high.
A few possibilities. 1. Zoloft (sertraline) is mildly stimulating (like caffeine) for many people. This side-effect may be interpreted as euphoria. 2. Manic reactions are possible from antidepressants. This may feel euphoric, but usually has an irritable or edgy component, and would continue & worsen with further doses. 3. It may be a psychological reaction to getting help, feeling optimistic after long discouragement, etc.