When treating those with substance use disorders, it's important to keep in mind Co-occurring Disorders, which you may also hear as Comorbidity or Dual Diagnosis. In this lesson, you will learn what psychiatric comorbidity is, how common it is, how it impacts prognosis and how it impacts treatment plans. Simply put, Comorbidity means two or more disorders occurring simultaneously. Can you guess what percentage of those with a substance use disorder also have a co-occurring psychiatric disorder? Let's stop to take a poll. According to the 2016 National Survey on Drug Use and Health, about 43% of adults seeking treatment for a substance use disorder were found to have a co-occurring mental disorder. That's right, close to half of those seeking treatment for substance use disorder also have another mental illness. Keep in mind the rates of comorbidity are lower in those not seeking treatment. However, studies have consistently shown that those with substance use disorders have high rates of comorbidity for Major depressive disorder, Bipolar I disorder, Anxiety disorders, Posttraumatic stress disorder, Antisocial personality disorder, Dysthymia and Borderline and Schizotypal personality disorders. You can further explore the epidemiology of comorbidity in the readings, but let's highlight a few common dual diagnosis. One study in 2013 found that Bipolar I disorder had the highest lifetime prevalence of substance use disorders at 60.3%. Of adults with ADHD, between 9% and 30% have histories of drug use disorders. And for patients with schizophrenia, the estimates of nicotine use are as high as 70 to 85%. Even though smoking is often not considered the most immediately life-threatening, it is the leading preventable cause of mortality worldwide. So why are these comorbidities so common? While we don't have one clear answer, there are three main theories. One theory is that, patients use substances to treat the symptoms of the underlying psychiatric illness, which is often referred to as self-medicating. While some drugs may help initially with the symptoms of the mental illness, sometimes this can also make the symptoms worse. Another theory is that there are many gene variants that may predispose an individual to developing both a substance use disorder and mental illness as well as different gene variants may result in increased vulnerability to developing a second disorder. For example, a person who smokes marijuana as an adolescent is that increased risk developing mental illness as an adult. A third proposed theory is the Kindling effect. By this we mean that substances and psychiatric illness may change the brain in ways that make the person more vulnerable to developing a more severe disorder, as well as more vulnerable to developing other mental illness. Whatever the reason, psychiatric disorders and substance use disorders are connected. So the presence of one should keep you on the lookout for the other. Mental illness typically has an earlier onset which is why early screening intervention and treatment may lower the risk of developing a substance use disorder. It's important to note that patients with comorbidity often have poor treatment outcomes than those who may have only one of the disorders. The clinical course of both disorders is more problematic as it can lead to earlier relapses, lower rates of long-term abstinence, more psychiatric comorbidity, more frequent hospitalizations and even higher rates of suicide. Here's a question for you. If you determine that your patient has co-occurring disorders, would you treat the symptoms separately or treat the symptom simultaneously? We treat them simultaneously. If we want to optimally treat one disorder, we really do need to treat both. Avoid waiting to treat the symptoms of mental illness until the substance use disorder is in a stable remission. For example, a provider might want to wait to address a patient's depression because they think it's a symptom of the substance use as opposed to being a pre-existing condition. One way to avoid these diagnostic dilemmas is to understand the development of the mental illness prior to substance use. Another way would be to ask the patient to describe psychiatric symptoms during significant periods of abstinence from substances. Ideally, we look for an integrated treatment approach where both disorders can be treated concurrently by an interdisciplinary team. So that pharmacotherapy, psychotherapy and social needs can be addressed. A common approach is to pursue treatments that are effective for both disorders separately. That being said, there are some psycho therapies that have been developed to target symptoms of specific combinations of disorders. For example, seeking safety is a cognitive behavioral therapy for those diagnosed with both post-traumatic stress disorder and substance use disorder. Hopefully, you walk away from this lesson with a better sense of what comorbidity is, two conditions at the same time. How common it is? Very common. How it can impact prognosis? Outcomes are typically worse. And how to approach treatment? We address both disorder simultaneously.
