Depression arises from complex interactions between brain chemistry, genetics, life events, and physical health. Imbalances in serotonin, norepinephrine, and dopamine, the neurotransmitters that regulate mood, motivation, and reward, are central to the biology of major depressive disorder. The American Psychiatric Association recognizes depression as a medical illness with both psychological and physiological components.
Chronic stress, unresolved trauma, and prolonged cortisol elevation can shrink the hippocampus and disrupt the prefrontal circuits that regulate emotion. Over time these changes reduce neuroplasticity, the brain's ability to adapt and form new connections, which is why early intervention with a thorough psychiatric evaluation matters.
Medical comorbidities including thyroid dysfunction, vitamin B12 deficiency, postpartum hormonal shifts, chronic pain, and substance use can mimic or worsen depressive symptoms. Identifying and addressing these contributors is a core part of root-cause psychiatric care at Evolving Mind and Body in Auburndale, FL.
