Final answer:
Dopamine is the neurotransmitter primarily associated with emotion, motivation, and addictive behaviors, like gambling. However, norepinephrine and serotonin also play roles in these functions, particularly relating to stress and compulsion.
Step-by-step explanation:
The neurotransmitter primarily involved in emotion, motivation, and addictive behavior is dopamine. This chemical messenger is critical for reinforcing behaviors that lead to its release, thereby providing feelings of pleasure, which can motivate individuals to repeat certain actions. Dopamine is released in higher amounts when a person engages in activities such as gambling, which can be exhilarating and stressful, leading to the reinforcement of the gambling behavior. Norepinephrine is another neurotransmitter that is associated with stress, arousal, or thrill, such as during gambling, and it may be increased to adjust the neurotransmitter levels. Furthermore, deficiencies in serotonin might also contribute to compulsive behavior, such as a gambling addiction. Overall, while dopamine is most commonly connected with reward systems and addictive behavior, it is important to recognize that the human brain is complex and usually involves a variety of neurotransmitters, like serotonin and norepinephrine, in intricate ways to regulate our behaviors and moods.