Which of the following is a potential side effect of lithium?

Lithium is a commonly used mood stabilizer in the treatment of bipolar disorder, and while it has many therapeutic effects, it also comes with a range of potential side effects. Among these, acne is indeed a noteworthy skin-related side effect that may arise in some patients taking this medication.

The development of acne can occur as a result of lithium's influence on hormone levels and sebaceous gland activity. While it is generally not one of the most severe or concerning side effects compared to others, it can affect a patient's quality of life and may require additional treatment or adjustments in therapy.

Other options such as neural tube defects, seizures, and cardiac dysrhythmias, while potentially related to medications or conditions, are not typically associated with lithium in the same way. Neural tube defects are more relevant to certain anticonvulsants or medications taken during pregnancy, seizures can occur due to a variety of reasons but are not a direct side effect of lithium, and while lithium can influence cardiac function, it is less commonly recognized for causing cardiac dysrhythmias in the absence of other confounding factors such as renal impairment or dehydration. Thus, the selection of acne as a side effect underlines a relevant and common concern associated with lithium treatment.