The Strong Link Between Schizophrenia and Diabetes
That there is a strong link between schizophrenia and diabetes is not a new discovery. The relationship between diabetes and schizophrenia has been known for more than 100 years. While after a century much about the connection is still not well understood, medical and mental health professionals are building knowledge about the connection and using it to develop better prevention and treatment for people who live with both schizophrenia and diabetes.
The number of people with both illnesses is significant. People with schizophrenia are three times more likely than the general population to develop type 2 diabetes (Toich, 2017). Further, 20-30 percent of people with schizophrenia will develop diabetes type 2 (Cohn, 2012). These numbers are too high to dismiss as coincidence. What is it that influences the connection between these drastically different medical and psychiatric conditions? Here’s a look at what researchers are discovering.
Schizophrenia, Antipsychotic Medication, and Diabetes
One culprit for the development of diabetes in people with schizophrenia is antipsychotic medication. Antipsychotics are an essential component of schizophrenia treatment. They’re necessary to reduce the hallucinations, delusions, and many other symptoms of schizophrenia. Antipsychotics, however, have dangerous side effects, including weight gain ("Are There Any Safe Antipsychotics in Diabetes Treatment?").
Weight gain from antipsychotic medications is often significant. Antipsychotic medications can cause obesity, high cholesterol, and an increase in triglycerides, or fats found in the blood. These conditions can cause type 2 diabetes.
Many different types of antipsychotics and atypical antipsychotics are available. Ideally, people with schizophrenia take medications that cause the least amount of weight gain, such as aripiprazole (Abilify) or ziprasidone (Geodon); however, this isn’t always the case. Multiple classic and atypical antipsychotics are available and widely used to treat schizophrenia. Chlorpromazine (Thorazine), clozapine (Clozaril), and olanzapine (Zyprexa) are among those that cause the biggest amount of weight gain.
Attributing diabetes to weight gain from medication has proven to be too simplistic. Sometimes, diabetes develops very rapidly after someone is newly diagnosed with schizophrenia. Researchers have found that some people who experience their first episode of psychosis already have indications of type 2 diabetes:
- Decreased glucose tolerance
- High fasting plasma glucose levels
- High fasting plasma insulin levels
- Increased insulin resistance
This happens either before or shortly after medication treatment begins, before weight gain and other side-effects have begun; therefore, the link between schizophrenia and diabetes isn’t merely from medication. There is something about schizophrenia itself that contributes to the development of diabetes.
Factors Contributing to the Schizophrenia and Diabetes Link
Without a doubt, medication-induced weight gain is part of the reason these two serious conditions co-occur. It’s just not the only factor. Knowing what else contributes to the development of diabetes in people with schizophrenia can lead to better treatment and management strategies.
These factors solidify the link between diabetes and schizophrenia:
- Genetics. There is a genetic component not yet fully understood that makes some people more prone than others to develop these illnesses.
- Developmental risk factors. Premature birth, low birth weight, and other pregnancy and delivery complications can contribute to both schizophrenia and diabetes.
- Lifestyle. Often, schizophrenia is associated with cigarette smoking, poor diet, and lack of exercise, all things that are detrimental to health.
- Social health problems. Low income, poor housing circumstances, and difficulty meeting basic needs are risk factors for serious health problems like the combination of diabetes and schizophrenia.
Living with both schizophrenia and diabetes presents numerous challenges ("Schizophrenia Makes Diabetes Management Challenging"). Understanding the unbreakable link can help lead to a treatment approach that incorporates the management of both illnesses together. This can improve the quality of life for people with combined type 2 diabetes and schizophrenia.
Last Updated: 09 January 2019
Reviewed by Harry Croft, MD