Comorbidity refers to the presence of one or more additional disorders or conditions that co-occur with a primary disease or disorder. In other words, it is when an individual suffers from two or more medical conditions at the same time. These additional conditions can exacerbate the symptoms and complicate treatment for the primary condition. Comorbidity is common in many mental health disorders such as depression, anxiety, bipolar disorder, and schizophrenia, where individuals often experience multiple co-occurring conditions that contribute to their overall illness burden.