Medical experts often encounter patients who have symptoms of more than one mental health condition at the same time, a phenomenon known as comorbidities. Understanding the causes of these comorbidities requires a deep dive into the complexities of the human brain and the various reasons why mental health conditions develop. Kristin Scaplen, an assistant neuroscience professor at Bryant University, emphasizes that comorbidities are a common and serious issue. Research indicates that the presence of comorbidity is linked to higher rates of suicidal thoughts, more severe symptoms, and overall lower quality of life.
Depression and anxiety are among the most common mental health comorbidities. Approximately 60% of individuals with depression also show symptoms of anxiety, and vice versa, according to the National Alliance on Mental Illness. Scaplen notes that individuals dealing with depression and anxiety are also more likely to have substance use disorders, with a prevalence of about 30%. There are three possible explanations for this correlation. First, the three conditions may share similar risk factors, meaning susceptibility to one could lead to susceptibility to another. Secondly, individuals with depression or anxiety may turn to substances as a way to cope with their symptoms, and finally, the substance itself may alter the brain, making it more vulnerable to anxiety or depression.
In terms of developing mental health conditions, Justin Kei, the medical director of The Debra Simon Center for Integrative Behavioral Health and Wellness, emphasizes the complexity of behaviors and genetics. For instance, in the case of schizophrenia, numerous risk genes for the disorder seem to contribute to the mental illness, but isolating a single gene as the sole cause is impossible. Environmental factors also play a role, with heavy marijuana use during adolescence being linked to a higher risk of developing schizophrenia. Other external influences on mental health include climate change, air pollution, substance use, and diet. Kei highlights the direct connection between the gut and the brain, emphasizing that what we eat can impact our emotions and thoughts.
Stress experienced during childhood can also shape the brain and potentially lead to mental illness, according to Scaplen. When it comes to the brain processing involved in mental health conditions, Scaplen explains that patients with anxiety often exhibit increased activity in the limbic system, where emotions are processed. Mental disorders involve disruptions to pathways in the brain and the neurotransmitters it uses for communication, with specific disruptions varying depending on the disorder. Patients with depression may experience reduced activity in their frontal lobes, while substance use can flood the brain’s reward circuitry, making it challenging for individuals with substance use disorders to stop drinking.
While physical brain differences are observed in these disorders, diagnosing them based on brain scans alone is not possible. Doctors still rely on patients’ reported symptoms, which are then compared to the Diagnostic and Statistical Manual of Mental Disorders criteria. Kei believes that as technology advances, mental health diagnoses may change, and what were previously thought to be comorbidities could turn out to be more interconnected.
In terms of treatment for multiple mental health conditions, experts note that depression and anxiety can sometimes be treated with the same medication, such as selective serotonin reuptake inhibitors. However, tailored treatments may be necessary to address different conditions effectively. Treating co-occurring disorders simultaneously, such as substance use and depression or anxiety, has been shown to be more beneficial. Kei emphasizes that treatment approaches may need to be adjusted based on the specific conditions present.
In conclusion, understanding comorbid mental health conditions involves a complex interplay of genetic, environmental, and behavioral factors. By addressing the interconnected nature of these conditions and providing comprehensive treatment, individuals can better manage their mental health and overall well-being.