Psychology MCAT Practice Exam 2025 – Complete All-in-One Guide to Ensure Your Success!

Serotonin is primarily involved in mood regulation because it plays a crucial role in stabilizing mood, feelings of well-being, and happiness. This neurotransmitter is synthesized from tryptophan and is found extensively throughout the brain and body. It is known to influence various physiological functions, but its impact on mood is particularly significant. Low levels of serotonin are often associated with mood disorders such as depression and anxiety, which is why many antidepressant medications target serotonin pathways, particularly selective serotonin reuptake inhibitors (SSRIs).

In contrast, while dopamine is closely associated with reward processing and pleasure, its role in mood is more indirect. Norepinephrine is involved in arousal and alertness and can also affect mood but is primarily linked to the fight-or-flight response and attention. GABA, being an inhibitory neurotransmitter, primarily contributes to calming neural activity and reducing anxiety rather than directly regulating mood. Thus, serotonin is the key neurotransmitter specifically linked to mood regulation.