Which of the following is an adverse reaction associated with SSRI use?

Weight gain is a well-documented adverse reaction associated with the use of selective serotonin reuptake inhibitors (SSRIs). This class of antidepressants can influence metabolic processes and appetite regulation, leading some patients to experience an increase in body weight over time. Weight gain may occur due to changes in appetite or metabolic rate caused by the medication, as SSRIs can affect serotonin levels, which play a role in satiety and appetite control.

While some individuals on SSRIs may initially experience increased energy levels, particularly as their mood improves, this is not considered an adverse reaction. Decreased appetite can occur in some patients, particularly at the start of treatment, but is not a common long-term side effect. Lowered blood sugar is also not directly associated with SSRI use; rather, it is a concern typically linked to other classes of medications, especially those used in the management of diabetes. Thus, weight gain stands out as the most relevant adverse reaction associated with SSRIs in this context.