Final answer:
Research indicates that alcoholism and smoking share common genetic factors, but environmental factors also play a significant role in drug dependence. The correct option is 2.
Step-by-step explanation:
Research on the genetics of drug dependence indicates that alcoholism and smoking share common genetic factors. Historical views on alcoholism have shifted, recognizing it as a disease with a potential genetic predisposition, rather than a personal choice.
This recognition has led to a more compassionate view of alcoholics, understanding their condition as a 'sickness' rather than 'badness'. In addition, scientific research supports the notion that both genetic vulnerability and environmental factors are necessary for the development of conditions like schizophrenia, implying that genetic factors alone cannot fully predict drug dependence.
Studies in neuroscience have documented that various psychoactive substances, including alcohol and nicotine, can lead to a compulsive pattern of use despite negative consequences, defining substance use disorder in DSM-5. Additionally, environmental factors, such as being raised in a household with substance abuse, significantly increase the risk of physical abuse and neglect, indicating that environment plays a crucial role in substance use and abuse.
Therefore, when considering the genetics of drug dependence, it is critical to understand that while genetic factors do play a significant role, the role of environmental influences is also substantial, contradicting the idea that environment plays a minimal role in drug abuse.