Hormone Health Hub: Expert Insights on Testing, Balance & Better Living — low serotonin symptoms

Neurotransmitter testing is one of the most powerful functional assessment tools available — but it requires a nuanced approach to interpretation. In this clinical overview, Dr. Kate Placzek of ZRT Laboratory outlines the key fundamentals every practitioner needs before reading a neurotransmitter report: from understanding patterns over numbers and treatment sequencing, to the clinical significance of low serotonin on SSRIs, GABA’s peripheral mechanisms, and when to run a diurnal catecholamine assessment.

As the days shorten and sunlight fades, four key hormonal systems come under pressure: vitamin D, serotonin, cortisol and melatonin. For those susceptible to Seasonal Affective Disorder (SAD), the disruption of these interconnected rhythms can trigger depression, fatigue, poor sleep and low mood. This article explains the science behind the SAD hormone pattern — and what you can do to support your body through the darker months.