Drugs, Brains, and Behavior: The Science of Addiction
What are the other health consequences of drug addiction?
People with addiction often have one or more associated health issues, which could include lung or heart disease, stroke, cancer, or mental health conditions. Imaging scans, chest X-rays, and blood tests can show the damaging effects of long term drug use throughout the body.
For example, it is now well-known that tobacco smoke can cause many cancers, methamphetamine can cause severe dental problems, known as “meth mouth,” and that opioids can lead to overdose and death. In addition, some drugs, such as inhalants, may damage or destroy nerve cells, either in the brain or the peripheral nervous system (the nervous system outside the brain and spinal cord).
Drug use can also increase the risk of contracting infections. Human immunodeficiency virus (HIV) and hepatitis C (a serious liver disease) infection can occur from sharing injection equipment and from impaired judgment leading to unsafe sexual activity. Infection of the heart and its valves (endocarditis) and skin infection (cellulitis) can occur after exposure to bacteria by injection drug use.
Does drug use cause mental disorders, or vice versa?
Drug use and mental illness often co-exist. In some cases, mental disorders such as anxiety, depression, or schizophrenia may come before addiction; in other cases, drug use may trigger or worsen those mental health conditions, particularly in people with specific vulnerabilities.
Some people with disorders like anxiety or depression may use drugs in an attempt to alleviate psychiatric symptoms, which may exacerbate their mental disorder in the long run, as well as increase the risk of developing addiction. Treatment for all conditions should happen concurrently.