Simvastatin Looks Promising in Treatment of Negative Symptoms of Schizophrenia
The statin drug simvastatin (Zocor) enhances the effects of risperidone on negative symptoms of schizophrenia, according to a 2017 article by Soode Tajik-Esmaeeli and colleagues in the journal International Clinical Psychopharmacology.
In the 8-week study, 40 mg/day of simvastatin enhanced the effects of 4–6 mg/day of the antipsychotic risperidone on negative symptoms of schizophrenia, such as apathy and withdrawal, but not positive symptoms such as hallucinations or delusions.
Other statins, lovastatin and pravastatin, have not had a similar effect, possibly because they do not cross the blood-brain barrier as easily as simvastatin does.
Simvastatin has other benefits as well. Like all statins it decreases lipid levels, reducing cardiovascular disease. People with schizophrenia and bipolar disorder are at especially high risk for cardiovascular disease.
Simvastatin also decreases inflammation (lowering IL-1 alpha and TNF-beta levels) and may be neuroprotective, as it increases brain-derived neurotrophic factor (BDNF), a protein that protects neurons and is important for learning and memory. Inflammation is increasingly implicated in schizophrenia and bipolar disorder.
There is also some evidence that statins can prevent depressions over long-term follow-up. Studies in women without depression and men who had recently had heart attacks both showed that those taking statins had a lower rate of future depression than those not taking statins.
Editor’s Note: These findings suggest a potential 5-fold benefit to simvastatin: 1) It reduces negative symptoms in schizophrenia. 2) It reduces inflammation. 3) It increases BDNF. 4) It decreases cardiovascular disease risk by lowering lipid levels. 5) It may prevent future depressions.
Other approaches to augmenting schizophrenia treatment include nutritional supplements vitamin D3 and folate. Patients with psychosis often have vitamin D deficits. Folate supplements can reduce homocysteine, which has been linked to cognitive deficits in schizophrenia.
Combination of SSRIs and Statins Better than SSRIs Alone
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.
Statins Reduce Drug-Craving in Mice
Statins are drugs that are typically used to lower cholesterol. Recent research on the drugs has focused on their effects on the brain.
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.
