When one medical condition occurs alongside another, it is known as comorbidity. In clinical terms, a patient who has a mental illness comorbid with a substance abuse disorder is considered to have a dual diagnosis.

In a previous segment we explored some of the methods of diagnosing and treating patients with dual diagnoses; this segment will explore why mental health issues and substance abuse issues often go hand in hand.

The Link Between Mental Health and Substance Abuse

According to a study released by the National Institutes of Health, people with severe mental illness – especially mood and anxiety disorders – were twice as likely to also have a substance abuse disorder as those without mental illness. Individuals with severe mental illness were also:

  • Four times as likely to be heavy drinkers;
  • 3.5 times more likely to use marijuana 21 times per year, or more;
  • 4.6 times more likely to use other drugs at least 10 times in their lives; and,
  • 5.1 times more likely to smoke cigarettes on a daily basis.

Additionally, young women with mental illness smoked cigarettes at rates higher than young women without mental illness.

Why Mental Illness and Substance Abuse Often Occur Together

Determining the cause of comorbid mental illness and substance abuse is a chicken and egg scenario: did the mental illness cause the substance abuse, did the substance abuse cause the mental illness, or did some third, unknown factor, cause both?

The reality is that the correlation between mental illness and drug abuse is complex with multiple factors at play:

  • Some drugs cause changes in the brain that can trigger the onset of one or more mental illnesses in individuals who had no sign of illness before the drug use;
  • Some people with existing mental illness use drugs and/or alcohol as a means of self-medicating, or treating, existing symptoms. However, their symptoms go unrecognized and undiagnosed until they become so severe that self-medicating on longer works, or the drug abuse actually makes the symptoms worse;
  • Some people might have an underlying health condition, such as chronic pain, which leads them to abuse drugs, which then trigger a mental illness; and,
  • There are also individuals for whom the mental illness and substance abuse occur at the same time, with no clear line of demarcation – such as a person exposed to extreme stress or trauma that triggers both PTSD and the need to use substances as a coping mechanism.

If someone has a dual diagnosis the substance abuse will inevitably make the mental illness worse, even if the drug use seems to relieve the symptoms at first. Having a dual diagnosis also means that the task of treating both conditions is often harder, especially if the individual is dependent upon the drug to treat the mental illness.

Dual Diagnosis Prognosis

Although a dual diagnosis is often difficult to treat, it is not impossible; and the prognosis for people who get the proper treatment is often good.

The key is in ensuring that patients get the proper mental health treatment in addition to the treatment for substance abuse. Luckily, mental health has come a long way in this country, and mental health professionals have a much better understanding of the mechanisms behind many severe mental illnesses.

Where mentally ill patients used to be locked away, and subjected to torturous treatments like frontal lobotomies and insulin-induced comas, there is now a wide range of medications that can both relieve the symptoms of the mental illness and reduce the patient’s drug dependence.

There have also been advances in cognitive therapy, both in the treatment of substance abuse and mental illness, which can help patients unlearn the old, damaging, thought patterns and behaviors that contributed to the addiction.

Cognitive therapy can also help patients learn new ways of coping both with the drug cravings, and with the underlying mental health issues that may have triggered the drug use in the first place. Recovery with a dual diagnosis is not fast – there is no quick fix – but with care and diligence, it is possible.