A recent study has found a possible reason for why the most popular class of antidepressants has proven ineffective in some patient groups.

Each year around six per cent of all adult Australians are affected by a depressive illness.¹On average, depressive illness affects one in six women and one in eight men.²

Selective serotonin reuptake inhibitors (SSRIs) are the most commonly prescribed antidepressant medication currently on the market, but up to one-in-three people living with depression are believed to receive no benefit from this class of medication.

Researchers from the Salk Institute, San Diego, USA have identified hyperactive neuronal cells in response to SSRI medication. This was done by directly examining human neuronal cells from people living with major depressive disorder (MDD). This may help with the current ‘trial and error’ approach used by doctors to tailor the right medications to those patients in whom SSRIs are ineffective.

The neuronal cells used were derived from the skin cells of patients and reprogrammed back into induced pluripotent stem cells (iPSCs). IPSCs are adult cells, when under specific conditions, the cells can be transformed back into an embryonic-like state. This enables the differentiation into any type of human cell type, like a neuronal cell.

Ev vivo, the neuronal cellswere studied for the responsiveness of increased levels of serotonin, which imitate the effect of SSRIs. In the presence of serotonin, non-responsive cells to SSRI medication show signs of hyperactivity compared to the healthy neuronal cells. This may explain why patients taking this medication are not experiencing any benefits.

To learn more about the researchers’ findings, head here.

References

1. Sane Australia, Depression. Available at: https://www.sane.org/mental-health-and-illness/facts-and-guides/depressionLast accessed: Feb 2019.
2. Beyond Blue, Statistics and references. Available at: https://www.beyondblue.org.au/about-us/research-projects/statistics-and-referencesLast accessed: Feb 2019.