Lately, Kiara has been having trouble sleeping at night, and has also experienced a sharp decline in appetite and energy level. A decrease in which of the following neurotransmitters might be responsible for Kiara's sudden change in behavior?

• A. Dopamine
• B. Serotonin
• C. Endorphins
• D. GABA

Answer: (B)

Verified step by step guidance

1. Understand the role of neurotransmitters: Neurotransmitters are chemical messengers in the brain that play a crucial role in regulating mood, sleep, appetite, and energy levels.
2. Identify the symptoms: Kiara is experiencing trouble sleeping, a decline in appetite, and low energy levels.
3. Link symptoms to neurotransmitters: Serotonin is a neurotransmitter that is known to regulate mood, sleep, and appetite. A decrease in serotonin levels can lead to symptoms such as insomnia, reduced appetite, and fatigue.
4. Consider other neurotransmitters: Dopamine is primarily associated with pleasure and reward, endorphins with pain relief and pleasure, and GABA with reducing neuronal excitability. These do not directly align with Kiara's symptoms.
5. Conclude the analysis: Based on the symptoms and the roles of the neurotransmitters, a decrease in serotonin is most likely responsible for Kiara's changes in behavior.