Which of the following is NOT a typical symptom associated with serotonin imbalance?

In cases of serotonin imbalance, increased energy is not typically associated as a symptom. Serotonin is a neurotransmitter that plays a crucial role in regulating mood, appetite, and sleep, and its imbalance is more often linked to symptoms such as changes in appetite, disruptions in mood, and sleep disturbances.

For instance, low serotonin levels are frequently connected to mood disorders like depression and anxiety, where individuals may experience lethargy, fatigue, and low motivation—contrary to increased energy. Similarly, changes in appetite can manifest as overeating or loss of appetite, and sleep disturbances such as insomnia or hypersomnia can occur due to serotonin's influence on sleep cycles. Hence, increased energy stands out as an atypical symptom when considering the effects of serotonin imbalance.