A newly diagnosed pregnant teenager has suspected new onset depression. Which lab should be included?

For a newly diagnosed pregnant teenager with suspected new onset depression, including a urine toxicology screen is crucial because it can help identify whether substance use is contributing to her depressive symptoms. Adolescents may be more prone to experimenting with substances, which can have significant effects not only on their mental health but also on their pregnancy.

Identifying the presence of drugs or alcohol can inform the treatment plan, ensuring that both the mother and the fetus receive appropriate care. Substance use can complicate the management of depression and is a critical factor to consider in this population.

In contrast, while a urinalysis could provide useful information about urinary tract infections or general health, it does not directly address the potential impact of substance use. An HIV test is important for all pregnant teenagers but is not specifically relevant to the immediate concern of depression and its potential underlying causes. A lead level may be important in certain contexts, particularly if there are environmental risk factors or concerns about exposure, but it is not as directly connected to mental health evaluation as a toxicology screen. Therefore, the urine toxicology screen is the most pertinent laboratory test to include in this situation.