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

Olanzapine is an atypical antipsychotic medication commonly used to treat conditions such as schizophrenia and bipolar disorder. One of the well-documented side effects of olanzapine is weight gain. This occurs due to several mechanisms, including increased appetite and changes in metabolism. As olanzapine can stimulate hunger and alter glucose metabolism, many patients experience significant weight gain during treatment. This side effect is particularly important for clinicians to monitor, as substantial weight gain can lead to other health issues, such as diabetes and cardiovascular problems.

In contrast, the other options, while they may occur due to other conditions or medications, are not commonly associated with olanzapine. Weight loss is generally not a side effect of this medication; instead, it often has the opposite effect. Hair loss is not typically linked to olanzapine, and there is no strong evidence to suggest that it causes insomnia, as some patients may actually experience sedation when taking the drug. Understanding the side effects of medications like olanzapine is crucial for managing treatment and ensuring the well-being of patients.