The pineal gland sits in the central portion of the brain and helps secrete hormones, including

hm (events in a 24 hour period)

In this picture the probe is pointing straight to the pineal gland after the brain has been cut in half by hemispheres: This one in particular belongs to an ADHD brain. This images shows that it is about 5 to 7x larger than a normal brain.

In this picture the brain has not been cut at all and by pulling back the cerebellum the pineal body is visible and labeled: This picture shows an adolescent ADHD brain where it is clearly post developed compared to a similar brain of another aolescents.