Comorbid, in medicine, refers to a disease or condition that occurs at the same time as another illness. Dictionary definitions differ:

• Some say comorbidity refers to two or more illnesses that occur simultaneously
  
  
• Some say it refers to one or more illnesses that occur at the same time as a primary condition.
  
  
• Some say it refers to two or more conditions that are present at the same time and independently of each other.

In bipolar disorder, the most common comorbid conditions are anxiety disorders such as:

• Generalized anxiety disorder
• Panic disorder
• Post-traumatic stress disorder (PTSD)
• Obsessive compulsive disorder (OCD)
• Agoraphobia

and others. Experts say just over 50% of people with bipolar disorder also have at least one anxiety disorder during their lives.

Studies have found that anywhere from 65% to as much as 95% of patients with bipolar have had one or more comorbid conditions in their lifetimes. Besides anxiety disorders, other psychiatric illnesses include:

• Substance abuse disorder (48-61%)
• ADHD
• Personality disorders

In addition, people with bipolar disorder are likely to have:

• Heart disease
• Obesity
• Diabetes
• Migraine
• And to be smokers

While there are many psychiatric drugs that can contribute to obesity and diabetes, these conditions have also been found to be higher than normally present in patients not taking medications.

The presence of comorbid conditions can complicate and worsen bipolar symptoms - and, in some cases, the opposite is true. This means, for one thing, that your doctor needs to be aware of all your medical and psychiatric conditions, as having more than one illness at the same time can make a lot of difference in what medications he or she prescribes.

So make sure you tell your psychiatrist all your symptoms and about all your illnesses. You'll be safer if you do.