Both substance abuse disorders and depression are mental illnesses that can disrupt significantly worsen overall quality of life. Substance addiction is the compulsive and uncontrollable craving for, then seeking of, addictive or dangerous substances. These substances can include alcohol, cocaine, heroin, or tobacco. Clinical depression is a consistent feeling of sadness, worthlessness, and/or hopelessness that can last for days or weeks. When this condition lasts for two weeks or more, it can be categorized as major depression. Both addiction and depression involve dopamine receptors in the brain, which are tied into the risk/reward system.
Statistically, depression and substance abuse are closely linked. This is called co-occurrence, dual diagnosis, or comorbidity.
Who Is at Risk of Co-Occurring Depression and Substance Abuse?
It can be difficult to untangle which condition came first, but depression and substance abuse each make the other condition worse. According to the Anxiety and Depression Association of America, 20 percent of people who suffer from a mental illness, including depression, also have a substance use disorder; similarly, around 20 percent of people struggling with substance abuse also suffer from a mental illness like depression. The National Institute on Drug Abuse notes that people with a mood disorder like depression, or an anxiety disorder, are twice as likely as the general population to suffer from drug abuse. At the same time, people suffering from a substance use disorder are twice as likely as the general population to have a mood or anxiety disorder. Generally, people who struggle with one problem are more likely to struggle with the other.
People abusing drugs are more likely to develop depression or other mental illnesses due to chemical changes in the brain. So people who develop an addiction – which is itself a mental illness – are more likely to develop co-occurring mental illnesses in the wake of brain structure changes. When substance abuse starts early in life – during adolescence, for example – brain structure changes occur more easily because the organ is still developing. This can lead to problems with cognition as well as mood or an anxiety disorder, such as depression, later in life.
People with depression more likely to self-medicate, thus leading to substance abuse. This can be especially true if depression has not been diagnosed, if the person is not receiving treatment for depression, or if the person is off needed medication. Although addictive substances like alcohol or cocaine can create temporary euphoria, which can feel like the depression is lifting, once the chemical begins to leave the body, the reduced dopamine is more likely to make the individual feel worse. Sometimes, this is referred to as withdrawal depression.
In some cases, if a person is on an antidepressant to treat their condition, but struggling with addiction to a substance, the antidepressant can interact with the substance. This interaction can either potentiate, or enhance, the antidepressant’s effects.
Addictive Substances Linked to Depression
Some addictive substances are more commonly abused by people who also struggle with depression. Here are a few of those substances:
- Alcohol: Statistically, about one-third of people diagnosed with major depression also struggle with alcohol use disorder. In these cases, depression typically occurs first. Because alcohol is a central nervous system, or CNS, depressant, it might make depression worse in the long run. Drinking alcohol while also taking antidepressants can lessen the effects of the antidepressants as well, making the depression worse.
- Marijuana: Although marijuana abuse and depression have been correlated, marijuana abuse does not cause depression. It is more likely that depression leads to abuse of marijuana, as the person wants to detach from their clinical depression. Marijuana abuse has been linked to triggering other mental illnesses, however, including psychosis or schizophrenia. If a person suffers from depression and abuses marijuana, they are at a higher risk of developing other mental illnesses later.
- Cocaine: People who struggle with addiction to cocaine are likely to feel seriously depressed or suicidal when they begin withdrawing from the drug, especially if they do not have a doctor’s oversight during the process. Depression is a major symptom of withdrawal from such a powerful stimulant, and without support for ending the addiction, that feeling can lead the person to relapse very quickly. Cocaine abuse is associated with triggering schizophrenia and psychosis as well.
- Nicotine: Many people who struggle with depression also smoke. Nicotine acts as both a stimulant and a sedative, offering a kick from stimulating the adrenal glands, as well as releasing dopamine into the brain. People who become addicted to nicotine could have started smoking as a way of self-medicating their depression, or they could have changed the structure of certain dopamine pathways in their brain so significantly that they develop depression, which makes quitting nicotine more difficult.
Treatment for Co-Occurring Depression and Substance Abuse
For people who struggle with either condition, depression or substance abuse, getting help is important. It is even more important for people struggling with a dual diagnosis of both disorders to get help, because depression and substance abuse can feed into each other.
Fortunately, combined treatment is an option. It is important to speak with a doctor or therapist about combined treatment options, and choose the best option for your specific case. In the past, treatment would sometimes attempt to treat one condition first before addressing the other, but research shows that simultaneous treatment for both disorders is most effective.
For substance addictions, detox is often the first step in the treatment process. Replacement medications, like buprenorphine or Suboxone, can ease opioid withdrawal; benzodiazepines work well to ease symptoms of alcohol withdrawal; and bupropion, the active ingredient in antidepressants like Wellbutrin, works well to ease people who are addicted to nicotine off smoking. Once the individual has detoxed from the addictive substance, behavioral therapy, in combination with mood-stabilizing medications if needed, has been the most effective treatment for both substance abuse disorders and mental illnesses. Individual and group therapy can help the person discover underlying causes of the addiction, which can lead to better treatment of depression or other mental health conditions.
Oftentimes, SSRIs or serotonin selective reuptake inhibitors are used to treat depression. Antidepressants tend to be more helpful in treating depression if this condition was the cause of substance abuse, and not the other way around, but they can still be an effective way to balance out a person’s mood while they work on overcoming addiction. In some cases, a person whose depression was caused by their substance abuse will discover that, once they overcome their addiction, they do not experience depression anymore.
Regardless of whether depression led to substance abuse, or the other way around, getting appropriate, combined treatment for both conditions is very important. This helps the individual better understand their triggers for cravings or addictive substances, and maintain sobriety in the long-term.