Written by Agwalogu Bob,
If you work in primary care, the ER, or really any part of general medicine, you’ve probably met patients with co-occurring disorders.
It could be a patient with crushing anxiety who drinks a bottle of wine a night to take the edge off. It could also be the young adult with back pain who’s become increasingly dependent on their opioid prescription.
It definitely isn’t a niche issue anymore. In fact, recent data from SAMHSA revealed that out of 61.5 million adults with mental challenges in 2024, 34.5% also had substance use disorder. Out of this number, more than 41% didn’t get the treatment they needed for either.
For some of the patients who fell in the crack, chances are the clinician they met didn’t know what to look for. That’s exactly what the guide is for. Read on as we discuss co-occurring disorders, why they happen, and most importantly, what you can actually do to help.
What is a Co-Occurring Disorder?
A co-occurring disorder is when someone has a substance use disorder and a mental health condition together at the same time.
You might also hear it called a dual diagnosis. We already gave two examples in the introduction: someone with social anxiety taking alcohol for confidence, and someone with PTSD abusing sleeping pills. As of 2024, approximately 7% to 8% of U.S. adults suffer from co-occurring mental illness and substance use disorder, according to Statista.
4 Things Healthcare Professionals Should Know About Co-Occurring Disorders
Now that we know what co-occurring disorders are and how prevalent they are, let’s look at four truths every healthcare practitioner should know about this condition.
Substance Use and Mental Illness are Bidirectional
Substance use disorder and mental illness have a two-way relationship.
On one side, there’s self-medication. This could be a person with PTSD who uses opioids or sleeping pills just so they can forget.
The second direction is substance use itself, actually causing or worsening psychiatric symptoms. People who consume alcohol heavily, for example, can also suffer severe depressive episodes.
In fact, research shows that 50% of the adults who misuse substances are also likely to suffer from one form of mental illness or another.
So, how do you know if what you’re looking at is a co-occurring disorder? Some common examples include:
- Depression and alcohol use
- Anxiety disorders with benzodiazepine misuse
- PTSD with opioid use
- Bipolar disorder with stimulant misuse
The problem? Diagnosing these issues in a single fifteen-minute consultation is almost impossible. You have to see the pattern over time before you can confidently determine the problem and decide on a proper treatment plan.
Integrated Treatment is the Most Effective
It can be tempting to want to treat co-occurring disorders as isolated cases. Most people do this. In fact, the medical system has historically walked separate paths, and treating in isolation has always been the model.
The truth, however, is that when addiction and mental illness are handled as separate cases, a lot of patients will fall through the cracks. The result? Increased risk of relapse. This is why integrated care is the most effective option.
Rather than addressing each condition separately, a single team handles the treatment programs for co-occurring disorders. In practice, that means:
- One coordinated care team for mental health and addiction
- Shared treatment goals
- Better communication between providers
- Fewer gaps in care
- More personalized treatment
- Better long-term outcomes
And it really works, too. A 2025 BMC Nursing literature review found that integrated, patient-centred care that combines psychosocial and pharmacological approaches is the most effective way to treat dual diagnosis. It consistently performs better than fragmented care.
Diagnosis is Highly Complex
Another thing healthcare teams should know about comorbid disorders is that diagnosis can be really complex. Why? Because symptoms tend to mask or overlap.
The quote below by the Mental Health Academy sums this up perfectly.
“Co-occurring mental health disorders are not the exception – they’re the reality for many clients. And they often present one of the most challenging landscapes for assessment and intervention.” – Mental Health Academy via LinkedIn.
Let’s look at some examples of this overlap using the table below:
| Substance-Related Presentation | Can Mimic or Mask |
| Alcohol or benzodiazepine withdrawal | Primary anxiety disorder (tremor, racing heart, panic) |
| Stimulant intoxication or withdrawal | Bipolar mania or hypomania (elevated mood, agitation, grandiosity) |
| Chronic alcohol use | Major depressive disorder (low mood, poor sleep, low energy) |
| Opioid withdrawal | Generalized anxiety or panic disorder (restlessness, GI upset, insomnia) |
| Cannabis-induced psychosis | Primary psychotic disorder (schizophrenia spectrum) |
| Stimulant-induced psychosis | Acute primary psychosis |
| Untreated PTSD hyperarousal | Stimulant intoxication or withdrawal |
As we’ve already established, you have to see these patterns over time before you can determine what exactly is happening.
Take Bipolar Affective Disorders, for example. According to Icarus Behavioral Health, if a doctor misses the hypomanic episodes, they can inaccurately diagnose the person with depression alone. Even worse, they can mistake it for just withdrawal from certain substances.
This is why watching for patterns is important. When symptoms only show up alongside substance use and clear up after a period of abstinence, they’re more likely to be substance-induced.
But when they persist even after complete abstinence, then you’re looking at a primary psychiatric disorder.
Recovery is a Long-Term Process
Finally, it’s important to understand that recovery doesn’t happen overnight. It takes time, structure, and consistency.
It’s also important to note that relapses do happen, but this doesn’t mean that the treatment failed. It could simply mean that the plan needs a bit of adjustment.
The biggest part of recovery? What happens after? Transitioning from structured care back to everyday life is a vulnerable point for many patients. Many of them end up getting readmitted within the first 30 days after discharge, especially when there’s no strong system in place.
This is why there should be a proper hand-off, which should actually feel like a continuation of care.
This means:
- Clear follow-up appointments before discharge
- Direct connection to outpatient or community services
- Medication continuity where needed
- Warm handoff, not just a referral slip
When these steps are in place, there’s a stronger chance of full recovery.
FAQs
How many people have co-occurring health conditions?
The number of people with these conditions differs based on the study you’re looking at. However, SAMHSA estimates that more than 34% of the 61.5 million people with mental challenges also struggle with substance use disorder.
Should substance use or mental health symptoms be treated first?
Neither should necessarily come first. Co-occurring disorders should be handled together using an integrated care model. Treating them separately may mean incomplete recovery and relapse.
How can clinicians determine whether a patient has a co-occurring disorder or not?
Clinicians can determine whether it’s a co-occurring disorder or not by looking at patterns. Probably the best giveaway is symptom persistence. If symptoms continue during the period a person is abstaining from substance use, then it may suggest an underlying mental health condition.
Co-Occurring Disorders: Final Thoughts
Co-occurring disorders are common, complex, and frequently missed. But they don’t have to be. By understanding the bi-directional relationship, embracing integrated treatment, and knowing symptoms that overlap, healthcare practitioners can make a real difference in patient outcomes.
Hopefully, this article has helped bring some clarity to a topic that often feels more complicated in practice than it looks on paper.
Author Bio
Agwalogu Bob believes great content doesn’t just inform, it resonates, and then sticks. For over eight years, he’s been helping agencies across four continents craft just that kind of content: sharp, engaging cut-through-the-noise copy across SaaS, finance, tech, health, and lifestyle.
When he’s not putting pen to paper, you’ll likely find him scouring the internet for funny memes.
Connect with him on LinkedIn or Medium.
Please also review AIHCP’s Substance Abuse Certification program and our CE courses as well, to see if they meet your academic and professional goals. These programs are online and independent study and open to qualified professionals seeking a four year certification