In bipolar disorder, which neurotransmitter alteration is described?

• A. Increased Glutamate
• B. Decreased Serotonin
• C. Increased GABA
• D. Decreased Acetylcholine

Answer: (A)

Heightened glutamatergic activity is a commonly described neurochemical change in bipolar mania. Glutamate is the brain’s main excitatory neurotransmitter, and when its signaling increases, circuits involved in arousal, motivation, and energy become overactive. This aligns with manic symptoms such as reduced need for sleep, increased goal-directed activity, and heightened irritability or risk-taking. Glutamatergic overactivity also interacts with dopamine pathways to amplify mood elevation and impulsivity. Mood stabilizers like lithium and valproate are thought to dampen glutamate signaling or NMDA receptor activity, helping to prevent and control manic episodes. Other options don’t fit as well: serotonin is involved in mood regulation but is not the primary alteration described in bipolar disorder; GABA—the major inhibitory neurotransmitter—tends to be less inhibitory during mania, so increasing GABA would counteract mania rather than describe it; acetylcholine changes are not the hallmark described for bipolar disorder.