Co-Occurring Disorders

Diagnosing patients who struggle with both substance abuse and mental illness can be complicated. There are many overlapping symptoms and symptoms that are changed or affected by one condition or the other. The signs that a patient may exhibit depend on the specific substance being used and the mental health condition. Some general signs of mental illness, substance misuse, or both, include:

• Unusual changes in mood or a depressed or anxious mood
• Difficulty thinking or concentrating
• Changes in behaviors that seem unusual and can’t be explained by a current situation
• Difficulty coping with ordinary responsibilities or normal stress levels
• Withdrawal from friends and family
• Decreases in performance at work or school
• Changes in eating or sleeping habits without another explanation
• Fatigue, tiredness, or lethargy and loss of interest in activities
• Decrease in personal hygiene
• Difficulties in relationships with others
• Changes in sex drive or sexual function
• Thoughts of suicide, self-harm
• Substance use that is out of control, causes cravings or withdrawal, or that takes over a large portion of time and energy, displacing other activities

Diagnosis of co-occurring disorders must be done by a healthcare professional. These professionals use accepted standards to determine which types of mental illness a patient has and whether or not they have substance use disorders. They rely on medical evaluations, patient interviews, observations, and talking to family members to make diagnoses.

There are many possible causes of co-occurring disorders. It may not be possible to identify what triggers two or more conditions in one individual, but there are several reasons why it is likely to happen. For instance, mental illnesses and substance use disorders have similar risk factors:

• A family history of mental illness or substance abuse
• Going through a very stressful or traumatic experience
• Having a chronic physical illness
• Experiencing abuse, neglect, or other type of trauma as a child
• Having a poor social support network, including poor family support

These risk factors make it more likely that a person will develop a mental illness, but also that a person will abuse or become dependent on drugs or alcohol. There are other risk factors specific to each type of condition, but these overlapping factors help to explain why so many people develop dual disorders.

It also may be possible that having a mental illness, especially one that has gone undiagnosed and untreated, triggers substance abuse. The individual who suffers with mental illness symptoms may turn to prescription or illicit drugs to self-medicate. It is an unhealthy but fairly common type of coping mechanism.

On the other hand, a person who misuses drugs and alcohol may be more likely to develop a mental illness. Mind-altering substances can impact the brain and mental health. They can trigger episodes of an underlying mental illness or contribute to the development of a mental illness in someone who is already predisposed to it by other risk factors, like family history.

Someone struggling with co-occurring disorders will need to go through a period of detox before continuing with a comprehensive treatment program. Detox is the process of a drug leaving the body, and when someone has been using long enough to develop a tolerance and cravings, they are likely to experience uncomfortable withdrawal symptoms during detox. The exact symptoms vary by individual and the type of substance, but generally may include:

• Pain
• Loss of appetite
• Insomnia or excessive sleepiness
• Irritability, anxiety, anger
• Disorientation and confusion
• Depression and anxiety
• Nausea, vomiting, abdominal cramps
• Tremors
• Sweating

In severe cases of addiction, withdrawal may cause serious and dangerous symptoms. Anyone who is struggling with substance abuse should go through detox under medical supervision, both to stay safe and to avoid relapsing.

Any combination of substance type and mental illness is possible, but there are some that are more common. For example, one study of hundreds of patients receiving outpatient care for substance use also screened the patients for mental illnesses. The results showed that depression and anxiety disorders were most common. The researchers also found that more than one-third of these patients had two or three underlying mental illnesses.

A study of patients in medically-assisted treatment for opioid drugs found that there were some common co-occurring mental illnesses: depression and anxiety disorders, bipolar disorder, schizophrenia, borderline personality disorder, narcissistic personality disorder, antisocial personality disorder, and attention deficit hyperactivity disorder.

With more severe mental illnesses, like schizophrenia and bipolar disorder, there are some more common types of substance use. For instance, with schizophrenia, rates of smoking and nicotine addiction are high. Schizophrenia also often co-occurs with abuse of marijuana and alcohol. Nearly half of people diagnosed with schizophrenia struggle with substance abuse of some type. Substance use is also very common with bipolar disorder, affecting as much as 60 percent of this group.