A large study in Denmark suggests that taking selective serotonin reuptake inhibitor (SSRI) antidepressants alongside cholesterol-lowering statin drugs improved depression more than SSRIs alone. The findings, by Ole Köhler and colleagues were reported in the American Journal of Psychiatry in 2016.
The study included 872,216 people in Denmark’s national health care database who took SSRIs between 1997 and 2012. The most common SSRIs were citalopram, sertraline, and escitalopram. Of these people taking SSRIs, 13.0% also took a statin drug, typically simvastatin. Those patients who were taking both an SSRI and a statin were less likely than those taking an SSRI alone to be hospitalized for any psychiatric problem, or for depression specifically.
Depression is known to be correlated with inflammation throughout the body. Statins reduce this inflammation as well as lowering cholesterol. A 2013 study by Ahmad Ghanizadeh and Arvin Hedayati in the journal Depression and Anxiety showed that the SSRI fluoxetine and the statin lovastatin reduced depression severity compared to fluoxetine alone.
The combination of SSRIs and statins did not seem to reduce deaths or suicidal behavior compared to SSRIs alone. Statins have some side effects, but combining them with antidepressants did not increase the risks associated with their use.
In 2015 Claudia Chauvet and colleagues reported in the journal Neuropsychopharmacology that the brain-penetrating statins simvastatin and Atorvastatin reduced cocaine seeking behaviors in mice that were taught to self-administer cocaine and then were denied access to it for 21 days compared to pravastatin, a statin that does not penetrate the brain as thoroughly. The researchers found that the brain-penetrating statins also reduced nicotine seeking, but not food reward seeking. The statins also worked in mice that had stopped seeking cocaine but relapsed due to stress, allowing them to abstain from cocaine seeking again.
Statins are considered a very safe treatment in humans. The ability of statins to prevent relapse to addictions in mice may mean that one day they could be used to treat addictions in people as well. A review article by Cassie Redlich and colleagues in the journal BMC Psychiatry in 2014 indicated that statins may reduce recurrence of depression in people. The researchers found that simvastatin had a protective effect while Atorvastatin was associated with increased risk of depression, so the choice of statins may be important for both depression and addiction.