<P> The antihistaminic properties of certain TCA - and TeCA - class antidepressants have been shown to contribute to the common side - effects of increased appetite and weight gain associated with these classes of medication . </P> <P> Antidepressant discontinuation symptoms were first reported with imipramine, the first tricyclic antidepressant (TCA), in the late 1950s, and each new class of antidepressants has brought reports of similar conditions, including monoamine oxidase inhibitors (MAOIs), SSRIs, and SNRIs . As of 2001, at least 21 different antidepressants, covering all the major classes, were known to cause discontinuation syndromes . The problem has been poorly studied, and most of the literature has been case reports or small clinical studies; incidence is hard to determine and controversial . </P> <P> People with discontinuation syndrome have been on an antidepressant for at least four weeks and have recently stopped taking the medication, either abruptly or after a fast taper . Common symptoms include flu - like symptoms (nausea, vomiting, diarrhea, headaches, sweating), sleep disturbances (insomnia, nightmares, constant sleepiness), sensory / movement disturbances (imbalance, tremors, vertigo, dizziness, electric - shock - like experiences), mood disturbances (dysphoria, anxiety, agitation) and cognitive disturbances (confusion and hyperarousal). Over fifty symptoms have been reported . </P> <P> Most cases of discontinuation syndrome last between one and four weeks, are relatively mild, and resolve on their own; in rare cases symptoms can be severe or extended . Paroxetine and venlafaxine seem to be particularly difficult to discontinue and prolonged withdrawal syndrome lasting over 18 months have been reported with paroxetine . </P>

In what year did the first drug to treat depression come out and what was this drug called