No abstract

The results indicate that nicotine influences brain regions involved in arousal and reward and suggest specific functional systems that may be linked to motivationally significant aspects of tobacco dependence.

No abstract

These findings suggest that the age at which exposure to marijuana begins is important. Early adolescence may be a critical period for effects that are not present when exposure begins later. These results are discussed in light of reported effects of marijuana on gonadal and pituitary hormones.

No abstract