What is Addiction?

This is the second in a series of blogs contributed by our PM clinician Gregory Rennie, who will introduce you to various aspects of addiction and its treatment using psychotherapy.  Gregory Rennie provides access to collaborative care with PM psychiatrists via the Psychotherapy Matters Virtual Clinic (PMVC) for his clients.

“Addiction” is a common and accepted word used to describe serious brain disorders associated with alcohol or substance abuse.  In the most recent Diagnostic Statistical Manual of Mental Disorders (DSM5), two types of of substance-related disorders are described:  substance use disorders and substance-induced disorders.

Words like “addiction” or “dependence” are no longer diagnostic terms and have been replaced by the term substance use disorder.  

Substance-induced disorders can be thought of as complications or consequences of substance dependence and abuse.  This group of illnesses includes intoxication and withdrawal as well as a number or other less well-known illnesses grouped into substance-induced mental disorders.  Examples of substance-induced mental disorders include alcohol-induced depressive disorder and cannabis-induced psychotic disorder.

Confusing? It certainly is. Substance-related disorders are a complex group of illnesses. Even experts in the field have yet to discover everything about this destructive group of serious disease. But what do we know so far?

Some research evidence including from brain imaging studies suggest substance use disorders are likely caused by dysregulation of neurological pathways having to do with reward, motivation, and memory. However, every part of the brain can be negatively affected by floods of chemicals or drugs like alcohol and other recreational substances.

Simply put, people with an alcohol use disorder or cocaine use disorder, for example, develop an irresistible ‘Go’ system in the brain and lack a strong ‘Stop’ system.  They have poorly functioning brakes.  After years of abusing chemicals, the wiring in the brain becomes altered. Changes that occur in brain biology influence how chronic users see themselves, others and the world around them.  Chronic heavy users of some substances may loose touch with reality temporarily or permanently.

Substance use disorders have biological, psychological, social, and for some, spiritual consequences.

Key characteristics of substance-use disorders are:

  1. Loss of control
  2. Preoccupation with use of a substance (thinking, seeking, using)
  3. Persisting in use of a substance despite negative consequences

These characteristics are complicated by denial.  The person with a substance use disorder may persist in use despite noticeable changes in behaviour at home and at work.  Others may notice the problem long before self-awareness improves.  The person may crave the effects of the drug and seek it out. He or she may be unable to recognize or acknowledge the negative impact addiction has on family and co-workers.

The person may repeat destructive behaviour despite high risk of of future damage to themselves and their relationship with others. Most of the time, professional help is required to restore physical and mental health, to prevent disability, injury, and premature death.

For more information, I strongly recommend the following resources:

  1. Centre for Addiction and Mental Health in Toronto, Ontario at www.camh.net
  2. National Institute on Drug Abuse in the USA at www.drugabuse.gov.

In my experience, it is possible to recover from the impact of chemical dependence/abuse or substance use disorder.


American Psychiatric Association. (2013). Diagnostic and statistical manual of mental disorders (5th ed.). Arlington, VA: American Psychiatric Publishing.


The views expressed in these blogs are the author’s own and not necessarily reflective of those of Psychotherapy Matters.  Information provided here and anywhere else on PsychotherapyMatters.com is for learning purposes only and should not be used to guide treatment of clients/patients. Copyright © 2016 PsychotherapyMatters.com

Gregory Rennie
Gregory Rennie

Gregory Rennie has been an addiction therapist since 2005 and has also worked at agencies in Southern Ontario as an addiction therapist and concurrent disorders specialist.

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