Final answer:
Chronic abuse of methamphetamine can lead to a reduction in dopamine transporters, resulting in various effects such as depression, weight loss, and Parkinson's disease. Correct option is 3.
Step-by-step explanation:
Methamphetamine abuse can lead to a reduction in the number of dopamine transporters in the caudate nucleus and putamen. This can result in various consequences for addicts, including developing depression, being less likely to be overweight, and being more likely to develop Parkinson's disease as they age.