Can Substance Abuse Cause Mental Illness?: Drugs, Mental Health, & Dual Diagnosis

Can substance abuse cause mental illness

Despite the recent rise in substance abuse, including the ever-growing opioid epidemic, that has launched the topic of addiction into the public eye, many people still find it a difficult subject to discuss because of the stigma attached it. Instead of being viewed as the chronic disease it is, addiction is often seen as something shameful and immoral that deserves punishment instead of help.

Similarly, though great strides have been made in recent years to destigmatize mental illness, many people are still afraid to be open about their mental health issues for fear of being belittled and told that it’s “all in their head,” or conversely being seen as “broken” or even dangerous.

Because of these stigmas, both substance abuse and mental illness are surrounded by misconceptions, including how they can affect each other. Substance abuse and mental illness often seem to manifest together in people, which raises an all-too-common question: Can substance abuse cause mental illness?

It’s a more complicated question than people think, and one that has multiple answers.


Though the two are definitely linked, the fact that drug use disorders and mental illness frequently appear together doesn’t mean that substance abuse necessarily causes mental health issues. This comorbidity is instead often the result of one or more of the following scenarios:

  • Undiagnosed mental illnesses may lead someone to abuse drugs or alcohol as a coping mechanism for an illness they don’t realize they have. Many times, it’s only when they have been checked into treatment for substance abuse that their mental illness is diagnosed, creating the false perception that the substance abuse is what caused it.
  • Certain drugs can cause users to experience multiple symptoms that mirror those in different mental health disorders, ranging from common symptoms like anxiety and depression to full-on mania or psychosis, which can be caused by amphetamines and hallucinogens. However, these symptoms are not long-term and will typically dissipate once someone has stopped using.
  • In some specific cases, drug use may set off the first symptoms of an underlying mental illness. For example, a drug-induced psychosis in an individual who is predisposed to schizophrenia but not yet experiencing symptoms can trigger their first episode, making it appear as though the drug itself caused the schizophrenia.  
  • Anxiety, depression, paranoia, and insomnia are also usually side-effects of withdrawal and can mimic mental illness symptoms until an individual has made it through the withdrawal period and they too eventually vanish.
  • Rather than substance abuse causing mental illness, there are many overlapping factors that can cause both substance abuse disorders and mental illnesses, including genetic vulnerabilities, a lack of essential chemicals in the brain, and outside influences like early exposure to trauma and stressful or abusive environments.

As you can see, the relationship between substance abuse and mental illness is anything but straightforward, and requires close examination rather than snap judgments.


So, while mental illness does not occur as a direct result of drug use, long-term substance abuse can create problems that, in turn, can trigger mental health issues. Some basic examples include:

  • The poor decision-making caused by chronic substance abuse can lead to getting arrested, which can create feelings of guilt that can bloom into depression and anxiety, which can become overwhelming alongside addiction.
  • Substance abuse also leads to a marked increase in risky behavior, such as having unprotected sex or sharing needles with people infected with hepatitis or even HIV. The consequences of contracting these diseases can, on top of everything else, result in intense grief and depression.
  • Long-term drug or alcohol use also increases a person’s chances of being assaulted or raped, the trauma of which can result in serious mental health issues like PTSD, depression, and anxiety.

It’s still very much untrue that substance abuse will “give” someone a mental illness that they didn’t already have, even if it wasn’t fully manifesting. However, drug and alcohol dependency can absolutely put people in situations that are extremely likely to cause the development of mental health problems.


Statistically, people diagnosed with mental illnesses such as anxiety or mood disorders are roughly twice as likely to suffer from a substance use disorder. Likewise, those diagnosed with a drug disorder are about twice as likely to also be suffering from mental illness.

A recent survey by the Substance Abuse and Mental Health Services Administration reported that in 2016, an estimated 8.2 million adults aged 18 or older had what is known as a co-occurring disorder, which is when someone is suffering from both mental illness and substance abuse, and the two have become inextricably tied to each other.

Co-occurring disorders, or dual diagnosis, as it is commonly referred to in rehabilitation treatment, is an umbrella term that can be applied to a wide and varied range of problems. For example, it can be used to refer to something as broad as the comorbidity of alcoholism and depression, but also restricted to a specific and severe mental illness such as schizophrenia and specific substance of abuse like marijuana, as well as milder mental illnesses and dependencies, like someone with an anxiety or panic disorder who is dependent on Xanax.

Making an accurate dual diagnosis can be challenging on account of substance abuse producing its own symptoms that can correspond to different mental illnesses, as previously mentioned. This means that the doctor has to be able to differentiate between which symptoms are a result of drug use and which ones could be from a pre-existing mental illness.           

Because making this diagnosis is so tricky, many people end up receiving treatment for just one or the other. Of those with co-occurring disorders, it is estimated that only 12 percent get treatment for both substance abuse and mental illness.


While the misconceptions caused by the lack of dialogue and education about both substance abuse and mental illness are a serious issue, the more pressing negative effect is that people struggling with either substance abuse or mental illness do not seek out help.

The same 2016 SAMHSA study reported that:

  • 19.9 million people aged 18 or older were classified as needing substance abuse treatment.
  • Only 10.8 percent of them sought and received treatment.
  • 13.5 percent of those who did not seek treatment claimed they were afraid of negative perceptions and opinions from their family, friends, and community.
  • Of the 5.5 million people aged 18 or older who were classified as needing mental health treatment but did not receive it, 32.7 percent claimed they did not seek it out for the same reasons.

Learning more about substance abuse, mental illness, and understanding how they work and affect each other in a person can help save lives and ensure that people receive the proper treatment needed.

If you or a loved one is struggling with substance abuse that is tied in with mental health issues, Maryland House Detox can help with taking that first step towards treatment and sobriety. Call us today at (855) 928-0596 or contact us online.

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