Antidepressant Failure Linked To Out Of Shape Brain Cells

When antidepressant medication works as intended, the results can be life-changing for patients suffering from depression. For around 30-percent of sufferers, however, the popular class of antidepressant medications called SSRIs simply does not work. Researchers have puzzled over this unexplained failure for years, but a new study may finally have the answer: out of shape neurons.

Selective serotonin reuptake inhibitors (SSRIs) are the most popular treatment for depression, but many people don't respond to the medication, forcing them to switch to dopamine-based solutions. For a small group of sufferers, the depressant is classified treatment resistant after multiple medications fail to bring relief.

The difference between people who respond to SSRIs and people who continue to suffer may lie in growth pattern differences concerning the neurons that utilize serotonin, a neurotransmitter, for communication. A clinical study involving 800 patients suffering from Major Depressive Disorder (MDD) found SSRI non-responders have 'out of shape' neurons compared to people who respond to SSRI treatment.

The research involved creating serotonergic neurons from study participants who provided skin samples used to produce pluripotent stem cells. While studying these serotonergic neurons, the team noted a difference in how the neurons were shaped. In non-responders, the neurons had longer neuron projections than those from responders, as well as lower levels of important genes related to developing neuronal circuits.

According to the study, both unusual features may pave the way for excessive neuronal communication in some parts of the brain, but result in a lack of adequate communication in other regions. This messed up communication may answer the question about why SSRIs aren't effective for some patients, but reverse the disorder in others.