The Substance Abuse and Mental Health Services Administration (SAMHSA) found that about 3.8% of the population, or about 9.5 million people, had any mental illness co-occurring with a substance use disorder (SUD) in 2019.
When it comes to depressive disorder specifically, an estimated 33% of people living with mental health issues were also diagnosed with a substance use disorder.
The good news is that this is such a common combination that there are well-researched interventions that can help people struggling with both disorders to make incredible progress, leaving substance misuse in the past.
The Connection Between Depression & Addiction
In some cases, depression may be a result of ongoing substance use and misuse. For example, alcohol is a depressant in terms of how it functions in the brain. When someone drinks alcohol heavily for some time, they can develop symptoms of depression as a result.
In other cases, substance use disorder follows symptoms of depression. When depression symptoms persist, becoming difficult to manage or even overwhelming, and are not treated properly, an individual may seek refuge from those symptoms by turning to substance use.
Self-medication using drugs and alcohol is a form of a substance use disorder. When it continues for some time, causing a psychological and physical dependence on the substance of choice, an addiction develops. Once this occurs, the individual must get treatment for the addiction disorder as well as the depressive disorder in order to find recovery.
With co-occurring disorders, it’s imperative to treat both disorders simultaneously. If only the substance use disorder is addressed, the symptoms of depression will likely lead to a relapse in substance use.
Risk Factors for Depression & SUD
One of the biggest risk factors for the development of a substance use disorder and a depressive disorder is treatment-resistant depression. When a patient seeks treatment for depression (including talk therapy, medications, or a combination of these) and finds no relief, they are more likely to turn to substances than someone with depression who can manage the condition with traditional therapies and medical interventions.
One study found that, in adolescents, several issues indicate an increased risk of developing depression as well as a substance use disorder, including these:
- Current depression symptoms
- Lack of coping skills
- Conflict with parents
- Unhappiness with school performance
- Behavior problems
Signs of Comorbid Depression & SUD
Signs of depression and substance use disorder can look different in different people depending on the severity of either issue, the drug of choice, and the individual’s personality.
Signs of depression may include the following: 
- Eating more or less than usual
- Sleeping more or less than usual
- Inability to focus
- Feeling guilty, hopeless, or agitated
- Physical pains
- Doing fewer things or having less interest in old hobbies
- Suicidal thoughts
Signs of substance use will vary widely based on the substance of choice but may include the following:
- Inability to manage responsibilities, such as work, school, or caring for dependent family members
- Extreme changes to physical appearance and health, such as weight loss
- Inability to manage finances, such as always being out of money
- Volatile mood swings that seem to come out of nowhere
- Increased isolation or only spending time with people who do the same drugs
When someone exhibits a combination of these symptoms, it can indicate the existence of a dual diagnosis of both depression and substance use disorder.
Challenges of Co-Occurring Depression & SUD
It is not easy to address depression or substance use disorders on their own, and it is far more complex when both disorders are present.
Especially when substances are used in an attempt to manage depression symptoms, it can make it harder to stop use of drugs and alcohol. Not only is there a physical dependence to think about, but the person may also feel that they are unable to function without drugs and alcohol due to their depression symptoms.
Additionally, it is common to experience some level of depression during the course of stopping use of substances even when no depression disorder is present. When significant issues of depression occur for this reason and also because of an underlying disorder, it can make the process of stabilization in early recovery a difficult path to navigate without relapse.
Treatment Options for Comorbid SUD & Depression
Depending on the drug of choice and the severity of the depression, as well as lessons learned from past attempts at treatment, different treatment options for comorbid SUD and depression may be more or less appropriate.
In most cases, a combination of different treatment options are recommended, including these:
- Medication for SUD: Buprenorphine/naloxone (Suboxone), buprenorphine hydrochloride, naltrexone, and other medications may be appropriate to treat substance use, depending on the primary substance of choice.
- Medication for depression: SSRIs (selective serotonin reuptake inhibitors) and other medications may be helpful to manage depression symptoms.
- Psychotherapy for depression: Talk therapy alone or with family members may be helpful in looking more deeply into the “why” behind the depression and substance use.
- Therapeutic intervention for SUD: Learning coping mechanisms for addressing real-life situations can help to limit the likelihood or duration of relapse.
Why Treat Depression & SUD Simultaneously?
Treatment of both depression and substance use disorder together can be challenging. There is no cure for either disorder, but both can be successfully managed.
Long-term recovery requires ongoing adherence to treatment long after residential rehab is complete — if residential treatment is even an option.
Too often, patients think that the “real” problem is either substance misuse or depression and try to only seek treatment for that issue. Some people may want to address the substance misuse first and then the depression, or vice versa.
Again, these two issues are deeply intertwined. It is almost impossible to enjoy a long recovery when only one issue is explored in treatment at a time.
The truth is that long-term recovery can only be realized when a patient has the tools to manage both disorders simultaneously, making dual diagnosis treatment an absolute necessity for building a strong foundation in recovery.