According to Harvard Health Blog, about 1 in every 10 Americans takes an antidepressant. The most commonly prescribed class of antidepressants is Selective Serotonin Reuptake Inhibitors (SSRIs).
SSRIs block the removal of serotonin from the synapse, allowing serotonin to signal longer on the post-synaptic neuron (Figure 1). The net effect is to allow serotonin signaling to occur following what would otherwise be an insufficient release of serotonin. It has been estimated that, at best, approximately 50% of patients using SSRI medications achieve positive clinical outcomes while some are effective for no more than 5% of patients.
Why don’t SSRIs work more often?
Lack of symptom improvement may be attributed to a number of things including: improper absorption, slow metabolic breakdown, and existing serotonin levels. SSRIs do not create more serotonin and therefore require a certain circulating levels of serotonin to have its desired clinical effects. This can be observed through 2 common clinical outcomes:
- Patients taking SSRIs for depression experience reoccurrence of symptoms over time.
- Antidepressant efficacy can be improved when serotonin synthesis is supported.
People suffering from depression often begin with low serotonin stores and it is hypothesized that extended use of SSRI medications will deplete serotonin stores further, regardless of baseline levels. It is well documented that serotonin support increases serotonin synthesis. In the handful of published studies, serotonin support along with SSRIs have been shown to be safe, effective, and further highlight the need to manage serotonin stores in depressed patients.
Guest author: Jennifer Farley is a manager of the Clinical Support & Education Department at NeuroScience, Inc. and one of the resident experts in psychiatric disorders.