- Dual Diagnosis or Co-Occurring Disorders: This refers to an individual that suffers with an Addiction and a Mental Health issue simultaneously.
- Attention Deficit Hyperactivity Disorder: People with Attention Deficit Hyperactivity Disorder (ADHD) frequently experience drug abuse. The individual may seek sedative drugs or marijuana to decrease the hyper condition, which can spawn other issues.
- Antisocial Personality Disorder: Antisocial Personality Disorder is a common mental ailment connected with addiction. In some instances, this illness causes the user to self medicate with drugs, and in others, certain drugs may cause this illness.
- Depression: Drug abuse may cause depression, and is generally connected with this particular mental illness. Chronic drug or alcohol abuse alters chemicals in the brain, which may cause depression or worsen it.
- Bipolar Disorder: Bipolar Disorder (BPD) is a mental illness which causes a person to fluctuate between a manic state and a depressed state; mental states at opposite ends of the emotional spectrum. This mental illness might be worsened by drug, alcohol or caffeine dependency.
- Mania: Some kinds of drug abuse may cause the condition known as mania. This is particularly true if stimulants, also known as uppers, are mistreated.
- General Anxiety Disorder: Many people who have addiction problems are afflicted by a general anxiety disorder. This mental illness can result in unwarranted feelings of anxiety caused by situations that are generally considered manageable.
- Panic Disorder: Panic attacks cause a person to feel stressed, or feel a sense of impending disaster. Panic attacks are associated with addiction particularly to meth amphetamines and cocaine, but may also be triggered through other alcohol and drugs.
- Obsessive Compulsive Disorder: Obsessive Compulsive Disorder (OCD) is another mental illness that has been associated with drug abuse. Chronic drug use or excessive drinking may cause this illness in otherwise psychologically healthy people.
- Post Traumatic Stress Disorder: Post Traumatic Stress Disorder (PTSD) happens when something so distressing takes place that a person they has ongoing difficulty dealing with it. Many people who suffer from this mental illness attempt to cope with it by using alcohol or drugs, however, this often intensifies the symptoms of PTSD.
- Phobias: Various kinds of drugs can create phobias within a person, which are a kind of mental illness. This may also be called paranoia, a common unwanted effect of marijuana and other drugs.
- Schizophrenia: Schizophrenia can be triggered by chronic use of alcohol and drugs. Individuals who are afflicted by this mental illness might use drugs to avoid the symptoms of this condition, but the drug use can have the opposite effect.