depression
"I was prescribed Zoloft 10 years ago when I went through a very stressful experience and started having panic attacks & depression  I found Zoloft to be fantastic; a true 'happy pill'!  Within a month, life felt like living again, my panic attacks ceased, I was far better able to cope with my circumstances at the time, and I was able to stop taking it a few months later.  I took it again a year later on the advice of a doctor, who suggested it for my chronic irritable bowel syndrome; unfortunately it did not work for this condition.  However, I mistakenly stopped taking Zoloft suddenly instead of gradually reducing the dose, and began having severe hypnic jerks at night , which are a known side effect."