Sun, Feb 12th, 2017

The nature of addictive disorders

What are addictive disorders? Are they indeed disorders? The nature of problematic psychoactive substance use continues to be a matter of controversy among the public and politicians; even among health professionals there is little consensus. Some have a view that repeated use of a substance (or gambling or gaming) represents personal choice (a “free-will decision”) even when problems are occurring. Some consider it reflects the social and interpersonal influences on consumption or that it provides pleasure when life is hard. Many schooled in the field of behavioral psychology recognize the important contribution of learned behavior and also the more subconscious influences of classical conditioning (think of Pavlov’s dogs salivating at the prospect of food). Some conclude that these social and psychological influences result in a habit, which can be unlearned just as other habits respond to this approach. Many, particularly those in recovery from a substance problem, consider it a disease with a biological foundation and that those affected will respond differently to substances than others and over time will develop an addictive disorder. No wonder people are confused!

How do we make headway through these conflicting notions? In truth, each of them contributes something to our understanding of the nature of addictive disorders and we should not summarily reject any of them. The key issue is that the nature of these conditions changes over time. On the first occasion somebody takes a substance or gambles or plays an on-line game, it is their choice. They may be encouraged to do so by their peer group or the people they are with at the time. Moving from occasional use to repeated use typically involves social and psychological processes whereby further use is encouraged by a positive experience of the substance but also by the interaction of others who are drinking, smoking marijuana, or gambling together. Substance use and related activities are “socially infectious” conditions.

Repeated use of a substance may not remain something that is a flexible behavior which can be changed when circumstances change. The reason for this is that it affects nerve circuits and nuclei in the brain. Psychoactive substances do this because they get through the blood-brain barrier and cause changes directly. In the case of gambling, gaming, and other repetitive behaviors, there is internal release within the nuclei of chemical transmitters. Repeated exposure to external substances and internal chemicals affects the vital functions of these nuclei (such as reward functions and survival responses such as the fight-flight reaction). As a result, adaptive changes occur in the nerve circuits in these nuclei, which mean they are in an altered state, which scientists call “allostasis”. The allostatic state means that a powerful internal drive develops which drives forward the use of that particular substance (or engagement in gambling or gaming ever onwards).

The driving force is the central feature of what becomes an addictive disorder. Disorder is defined as a set of symptoms and features which has a known cause or predisposing factors, and has a distinctive course or “natural history.” When the internal drive has developed, repeated substance use becomes the norm to maintain the allostatic state; no more is it a free-will decision. If substance use does not continue, the person feels its lack – hence the common statement that addicted people make, that “I need to take [the substance] in order to feel normal”.

Importantly, the changes which occur in the brain nuclei are long-term ones; indeed they may be permanent. Much is known now about the mechanisms involved. Heightened dopaminergic neurotransmission arising from repetitive substance use in turn induces the formation of new nerve fibers and synaptic connections (these are termed “neurogenesis” and “neuroplasticity”) and so the brain becomes “hard-wired” for substance use. No longer can that person have a single glass of an alcoholic drink and then stop; the “volume control knob” is no longer functioning. The default for that person is to drink heavily and indeed they may do so until they pass out or there is no more alcohol available.

We now have a situation where a persistent driving force exists for that substance – and closely related substances. It results in the persistent use of the substance to the extent that the body’s natural defense mechanisms are overwhelmed and an array of disease states occurs. For alcohol, these can include liver disease, heart disease, muscle disorders, and endocrine abnormalities due to the direct toxic effects of alcohol. For cigarette smoking, the diseases (lung disease and various cancers) occur because of the other constituents of tobacco rather than the addictive substance which is nicotine. The addictive effects of codeine-containing tablets often reflect the toxicity of the other constituent such as ibuprofen in those who take Nurofen Plus (peptic ulcers and gastrointestinal bleeding) and liver disease due to paracetamol in people taking Panadeine in its various strengths. Addictive disorders also cause physical diseases due to the person fueling their addiction to the detriment of their personal care, thus allowing diseases which might have been identified at an early stage to become advanced and untreatable. Mental disorders; various forms of brain damage; and personal, financial, work, and family problems occur typically in people who have addictive disorders. Consequently, life begins to unravel.

Addictive disorders have one more characteristic, which is why they are such powerful and destructive conditions. They play tricks with the conscious mind. The “internal driving force” tends to disturb the person’s logic so that he or she tends to blame others or external circumstances for their predicament. A further development of this is “denial”, where the person understates the extent or impact of their substance use and may reject that it is a problem. Not for nothing are these disorders described as “sneaky” and “baffling”.

It is important that health professionals keep abreast of the developments in the biology of the brain which explain the powerful and often subconscious nature of addictive disorders. Most crucially, there should be an understanding of the need for the patient to abstain from the addictive substance or behavior and to rebuild their life based on that. When a powerful engine is out of control, it is essential to deprive it of fuel. On the basis of sobriety, the underlying issues (often stemming from adverse experiences in childhood or the nature of their upbringing) can be addressed so that the patient experiences a sense of healing and the ability to move forward and be in the “driving seat” of their lives.