Which side effect is NOT typically associated with SNRIs?

Weight gain is not typically associated with SNRIs (serotonin-norepinephrine reuptake inhibitors). Generally, SNRIs can produce a range of side effects, including nausea, insomnia, and tremors. Nausea is a common initial side effect when initiating treatment with SNRIs, largely related to their effect on serotonin levels in the gastrointestinal tract. Insomnia may occur due to the stimulant-like properties of norepinephrine, which can affect sleep patterns. Tremors can also arise, particularly in the context of increased norepinephrine activity, which can enhance motor activity.

Conversely, weight gain is primarily a side effect associated with certain other classes of antidepressants, especially those that have a more pronounced impact on serotonin, such as certain SSRIs (selective serotonin reuptake inhibitors) or atypical antipsychotics. This differentiates weight gain from the more commonly observed side effects associated with SNRIs, affirming why it is not expected in patients treated with this class.