Bipolar disorder is a serious psychiatric condition that causes people to experience extreme mood swings — from mania to depression. The illness can be treated through medications, and people with bipolar disorder also find that counseling may help.
It's not unusual to see posts on celiac disease/gluten sensitivity forums from people with bipolar disorder who report that their symptoms improved or even abated completely when they adopted the gluten-free diet. In addition, two studies in the medical literature suggest that people with either celiac disease or gluten sensitivity may suffer from slightly higher rates of bipolar disorder than the general population.
However, like many of the possible links between gluten ingestion and mental conditions, much more research is necessary before it will be clear whether following a gluten-free diet might help some individuals with bipolar disorder.
Anti-Gluten Antibodies Found in People with Bipolar Disorder
Only three medical studies have been performed to look at whether people with bipolar disorder have heightened levels of anti-gluten antibodies in their blood streams.
In the most extensive study, published in 2011, the researchers tested 102 people with bipolar disorder and 173 people without a psychiatric disorder. They measured levels of the antibodies AGA-IgG and AGA-IgA, both of which are not specific to celiac disease but which may be useful as tests for gluten sensitivity. They also measured deamidiated antibodies to tTG-IgA and tTG-IgG, considered very sensitive celiac disease tests.
The study found that individuals with bipolar disorder had a much higher risk of having increased levels of IgG antibodies to gluten when compared to those without bipolar. Although people with bipolar disorder also had a higher incidence of other laboratory findings that are associated with celiac disease, those findings were not statistically significant.
The levels of antibodies in people with bipolar disorder did not correlate with their total symptoms (measured in several different ways), their medical history, whether they had any gastrointestinal symptoms, or with their use of specific psychiatric medications.
Nearly half of those with bipolar disorder carried the celiac disease genes (i.e., the genes that predispose you to celiac disease), but those with the genes were no more or less likely to have increased antibodies to gluten.
Second Study Looks at Mania in Bipolar and Gluten Antibodies
The same group of researchers published a study in March 2012 looking at markers of gluten sensitivity and celiac disease in acute mania, a hallmark symptom of bipolar disorder. They found that people hospitalized for mania had significantly increased levels of IgG antibodies to gluten, but did not have raised levels of other types of celiac disease-specific antibodies.
Interestingly, when measured six months after hospitalization, the bipolar patients' average levels of IgG antibodies had dropped, and were not significantly different from those of the control subjects. However, those bipolar patients who still had elevated levels of IgG six months later were much more likely to have been re-hospitalized for mania within that time frame.
"The monitoring and control of gluten sensitivity may have significant effects on the management of individuals hospitalized with acute mania," the researchers concluded.
The third study, published in 2008, didn't look specifically at bipolar disorder and gluten; instead, it looked at a broad array of psychiatric conditions, including bipolar disorder, and whether they were more likely to occur in children with celiac disease or with positive celiac blood tests. The study found neurological or psychiatric problems in nearly 2% of children with celiac or gluten sensitivity, a rate slightly higher than the 1.1% found in control subjects.
Gluten Implicated in Other Mental Illnesses
There's little doubt that people with celiac disease and gluten sensitivity suffer from higher-than-normal rates of anxiety and depression.
Gluten and depression are linked in a variety of studies, including research dealing with celiac disease and research dealing with non-celiac gluten sensitivity. Meanwhile, gluten and anxiety also appear to share a relationship. Still, it's not clear whether gluten itself may contribute to symptoms of depression and anxiety, or whether other mechanisms such as nutritional deficiencies caused by gluten-induced intestinal damage may lead to those psychiatric symptoms.
However, some studies have found that adhering to a strict gluten-free diet seems to help some symptoms of both depression and anxiety in people with celiac disease and gluten sensitivity.
Psychiatrists also have speculated about a potential link between gluten and schizophrenia, and some case reports indicate there are people with schizophrenia who might improve on a gluten-free diet. However, mental health experts suspect the number of people who might improve is very small — on the order of a few percent.
Will Gluten Be Implicated in Bipolar Disorder?
Much more research is needed to determine if gluten plays any role in bipolar disorder. The researchers in the first study who looked specifically at anti-gluten antibodies in people with bipolar disorder noted that some antibody levels — but not all of them — were much higher in people with bipolar disorder.
"It is likely that the individuals with bipolar disorder who have increased antibodies to gliadin share some pathobiological features of celiac disease, such as abnormal absorption of ingested food proteins, a finding which is also consistent with the increased levels of antibodies to bovine casein which have also been found in bipolar disorder as well as recent-onset psychosis and schizophrenia," the researchers said in their analysis. "However, the mechanism of the increased antibody response to gluten is likely to be different in bipolar disorder in comparison to celiac disease."
The researchers concluded: "At this point, it remains to be determined whether gluten proteins or the observed elevated immune response to them have any role in the pathogenic mechanism of bipolar disorder or have the potential to serve as biomarkers of disease diagnosis or activity." Future studies should include gluten-free diets in bipolar disorder patients with elevated anti-gluten antibodies, they said.
Dickerson F. et al. Markers of gluten sensitivity and celiac disease in bipolar disorder. Bipolar Disorders. 2011 Feb;13(1):52-8. doi: 10.1111/j.1399-5618.2011.00894.x.
Dickerson F. et al. Markers of gluten sensitivity in acute mania: A longitudinal study. Psychiatry Research. 2012 Mar 2. [Epub ahead of print].
Ruggieri M. et al. Low prevalence of neurologic and psychiatric manifestations in children with gluten sensitivity. Journal of Pediatrics. 2008 Feb;152(2):244-9. Epub 2007 Nov 19.