What type of drugs are commonly associated with weight gain?

Tricyclic antidepressants are commonly associated with weight gain due to several mechanisms. These medications can increase appetite and cause metabolic changes that lead to weight retention. Additionally, tricyclic antidepressants often influence neurotransmitter systems related to hunger and satiety, leading to increased food intake.

While beta-blockers can also contribute to weight changes, their effect is generally more variable, and some individuals may not experience significant weight gain. ACE inhibitors are primarily used to manage hypertension and heart failure and are not typically linked to changes in weight. Antihistamines may cause sedation, which can lead to a less active lifestyle and potential weight gain but are not as prominently associated with it when compared to tricyclic antidepressants. Thus, tricyclic antidepressants stand out as the primary class known for their weight gain side effects.