Do Antipsychotic Medications Cause Diabetes?

Whether antipsychotic medications cause diabetes is a legitimate concern. This type of medication is widely used to treat psychotic disorders like schizophrenia, bipolar disorder and a host of other conditions.

Antipsychotics can do a great deal of good, alleviating mental illness symptoms and increasing quality of life; however, people treated with antipsychotics have a higher risk than the general population of developing type 2 diabetes, a serious illness that can and does lead to many other health problems. Therefore, health professionals are investigating to determine if antipsychotic medications do cause diabetes.

Reasons Why Antipsychotic Medications May Cause Diabetes

A common side-effect of antipsychotics is weight gain. Overweight and obesity are top risk factors for type 2 diabetes. The weight gain associated with this type of psychiatric medication is significant. Thirty percent of the general population is obese, whereas, among people with schizophrenia who are taking antipsychotic medication, the obesity rate is 40-60 percent (Llorente, 2006). Because of this weight gain problem, developing new type 2 diabetes or worsening existing diabetes is a serious risk.

Also implicating antipsychotic-induced weight gain as a cause of diabetes is that 75 percent of diabetes diagnoses that happen after someone begins taking antipsychotics involve weight gain (Rosak, 2003). This number is too high to dismiss as coincidence.

That statistic also tells us something else: If 75 percent of new diabetes diagnoses involve weight gain, 25 percent involve other factors. There seems to be more to the association between diabetes and antipsychotic medication than weight gain. While exact causes are still under investigation, multiple studies have shown that lifestyle factors are noteworthy, such as:

• Inactivity
• Poor nutrition
• Tobacco use
• Non-adherence to any type of treatment
• Impaired insight (such as not understanding benefits and risks of medication)
• Poor access to medical and mental health care

If someone is living an unhealthy lifestyle, which is another risk factor for type 2 diabetes, and then begins mental illness treatment with antipsychotics, they could be at greater risk for diabetes than people with a similar lifestyle not taking antipsychotic medication. While researchers speculate that there are other factors at work in the development of diabetes—biological or genetic, for example—much more research is needed to confidently proclaim additional reasons why antipsychotics may cause diabetes.

Understanding the reasons behind antipsychotics and diabetes is complex. Not all antipsychotics are the same, nor do they carry equal risk of type 2 diabetes development.

Antipsychotics: Type Matters in Diabetes

Two classes of antipsychotics are available: conventional (typical) and atypical. Scientists, pharmacists, and doctors aren’t quite certain how each class works. It’s speculated that conventional antipsychotics block dopamine receptors in the brain while atypical drugs (the newer class) block multiple chemical receptors rather than just dopamine.

Of the two general classes, atypical antipsychotics are far more likely to cause or worsen diabetes. Common atypical antipsychotics include:

• aripiprazole (Abilify)
• asenapine (Saphris)
• clozapine (Clozaril, Clopine, CloZAPine Synthon, Denzapine, FazaClo, Zaponex)
• iloperidone (Fanapt)
• lurasidone (Latuda)
• olanzapine (Zyprexa)
• paliperidone (Invega)
• quentiapine (Seroquel)
• risperidone (Risperdal)
• ziprasidone (Geodon)

These carry different degrees of diabetes risk as determined by the amount of weight gain associated with each type. Amount of weight gain is unknown or undisclosed for some medications.

Atypical Antipsychotics with the Least Amount of Weight Gain

• aripiprazole
• ziprasidone

Atypical Antipsychotics Causing Moderate Weight Gain

• quetiapine
• risperidone

Atypical Antipsychotics Causing Excessive Weight Gain

Excessive weight gain means an increase of 10-30 percent of weight before beginning antipsychotics. Researchers include the following atypical antipsychotics in this category:

• chlorpromazine
• clozapine
• olanzapine

Atypical antipsychotics, weight gain, and diabetes appear to have a strong cause-and-effect relationship. This is problematic because of the wide use of these medications.

Who Takes Atypical Antipsychotics?

As their name implies, these pharmaceuticals treat psychotic disorders such as schizophrenia. They are used to treat many other mental disorders as well. You or a loved one might take an atypical antipsychotic for conditions like:

• Bipolar disorder
• Eating disorders
• Depression
• Anxiety
• Obsessive-compulsive disorder (OCD)
• Post-traumatic stress disorder (PTSD)
• Borderline personality disorder
• Autism
• Tic disorder
• Tourette’s syndrome
• Dementia (the psychological and behavioral symptoms)

Because they are used so extensively and carry a risk for the development or worsening of type 2 diabetes, both doctors and patients should take precautions. Anyone prescribed these medications should:

• Establish a record of baseline weight, blood sugar levels, and other health indicators
• Have regular screenings for diabetes risk factors
• Discuss with their healthcare provider their unique benefits and risks of taking the drug
• Develop a plan for creating and maintaining a healthy lifestyle. Including weight management

While evidence points to the possibility that atypical antipsychotics cause diabetes, this doesn’t mean that you should absolutely avoid them ("Are There Any Safe Antipsychotics in Diabetes Treatment?"). This type of medication does carry many benefits that often outweigh the risks, especially if the above precautions are taken. Also, more studies are needed to make definitive claims about atypical antipsychotics and diabetes. At this point, knowing the risks will help you monitor your health and lifestyle to minimize serious illness.

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