What Are Complex Conditions?
Individuals with complex conditions face a mix of symptoms stemming from more than one mental or physical health disorder. For instance, it’s not uncommon to see someone diagnosed with ADD/ADHD who also struggles with substance abuse—this is referred to as dual diagnosis or co-occurring disorders. Others may live with multiple mental health conditions simultaneously, known as comorbidity. In many cases, mental health challenges are also linked to physical issues like brain injuries, hormonal imbalances, obesity, or chronic infections. These layered conditions can severely disrupt daily functioning, affecting performance at work, in school, at home, and within personal relationships—ultimately reducing overall quality of life.
Who Is at Risk for Complex Mental Health Conditions?
Roughly 1 in 5 adults in the U.S. experience a mental health issue annually, and nearly 45% of those individuals meet criteria for two or more disorders. At Amen Clinics, we frequently treat patients dealing with complex cases, often involving overlapping biological and psychological conditions. Most of our patients arrive after trying various treatments elsewhere with little to no relief, highlighting the need for a more comprehensive diagnostic approach.
Why Complex Conditions Are Often Hard to Diagnose
When multiple disorders are present, accurate diagnosis becomes even more crucial to effective treatment. Unfortunately, in many traditional healthcare settings, diagnoses may be incomplete due to a lack of thorough evaluation. Mental health providers often overlook the brain itself and fail to consider biological, psychological, social, and spiritual influences on symptoms. At Amen Clinics, we go deeper, using tools like brain SPECT imaging and detailed lab testing to uncover root causes. (Learn more about BRIGHT MINDS risk factors that may be contributing to your symptoms.)
Common Psychiatric Disorders Involved in Complex Conditions
Many people experience a combination of mental health disorders. Below are some of the most frequently diagnosed conditions found in complex cases:
Studies show that around 30% of individuals with ADD/ADHD also suffer from depression, and nearly 50% also struggle with anxiety. If left untreated, half of adults with this condition are at risk of developing substance use disorders. Bipolar disorder and other comorbidities are also frequently reported.
Generalized anxiety disorder often co-exists with depression, substance use, and bipolar disorder. At Amen Clinics, we’ve found that anxiety and depression occur together in approximately 75% of cases. People with anxiety are also twice as likely to misuse drugs or alcohol compared to the general population.
Over 50% of those with bipolar disorder also have an anxiety-related condition. This disorder is frequently linked to ADD/ADHD, eating disorders, mood and personality disorders, and substance abuse.
Cognitive decline, including Alzheimer’s and other forms of dementia, is often seen alongside depression, anxiety, and substance abuse, which may further complicate the clinical picture.
Research published in JAMA shows that nearly 58% of individuals with major depressive disorder also have a substance abuse problem, 37% have an anxiety disorder, and about 32% live with a personality disorder. Substance misuse is roughly twice as prevalent among those with depression compared to those without.
OCD is often accompanied by anxiety, depression, bipolar disorder, and panic disorders. Research shows lifetime risks for those with OCD include:
Depression (up to 80%)
Bipolar disorder (up to 35%)
Generalized anxiety disorder (30%)
Specific phobia (22%)
Social anxiety disorder (18%)
Panic disorder (12%)
Schizophrenia (12%)
Up to 80% of people with PTSD experience at least one additional mental health condition during their lifetime. Common comorbidities include depression, anxiety, substance use disorders, and borderline personality disorder.
Research indicates that individuals with schizophrenia often have additional mental health conditions, such as:
Depression (50%)
Substance abuse (47%)
PTSD (29%)
OCD (23%)
Panic disorder (15%)