Boston Psychiatrist’s Straight Talk About Addiction and the Brain

Addictions: The Big Picture

Drug addiction has remained a stubborn problem for individuals, families and societies for thousands of years. It is only in the past 20 years that science has been able to clarify one of the factors: addictions cause lasting changes in the human brain that are difficult to reverse.

Although we have new insights into the flexibility of the normal adult human brain, the brain “high-jacked” by addictions becomes wired up in limiting, inflexible ways over time: it seems that only the “drug of choice” can satisfy the cravings and need that appear as powerful as the threat to survival itself.

Thus the current working definition of addiction:

Addiction is a chronic relapsing brain disorder where the addict has lost control of his ability to choose whether to take or not take the drug in the face of negative health, social or legal consequences.”

The “Decade of the Brain” and Recent Findings

The 1990s were declared the “Decade of the Brain” by presidential proclamation (President George H.W. Bush). In 1996, the Dana Foundation, a non-profit in collaboration with the Society for Neuroscience, launched Brain Awareness Week (BAW) and since then has sponsored it annually in March. BAW focuses on the field and new findings in neuroscience, primarily targeting educational opportunities. It consists of a global coalition of partners including government agencies, 2,000 universities, hospitals, service organizations and professional associations.

BAW utilizes public lectures, laboratory tours and dynamic, enlightening museum exhibits (among other things) to connect biomedical research with its benefits to public health, expand awareness of neurological disorders and to contribute to a general understanding of basic brain functions.

One of the most startling and potentially useful discoveries in the past 20 years is that of neuroplasticity – the fact that the healthy, mature human brain is dynamic and constantly changing. This research has shattered long-held beliefs that the human brain completed its formative structure at about 5 years of age; no new cells would appear and regular neuronal death was the expected norm until actual death.

It turns out that the human brain at all ages is highly responsive to external stimuli and change.”

The engine of response involves the connections between neurons, the electrical and chemical connectors, neurotransmitters and receptors. Although genetic factors play a modulating role, the connections between neurons (in the normal brain) are dynamic and are capable of change within minutes of stimulation. Some of the external triggers that we have become familiar with are: new learning, but also negative factors such as stress, combat, drug abuse and even the old controversial parental neglect and child abuse.

Possible Reversibility

One of the most important take-home messages from the studies of brain vulnerability and plasticity is the notion of reversibility. Anyone working in the Addiction Medicine field knows how hard it is to give up an addiction once it has become established, but we now know scientifically that it may be reversible.

Not entirely unexpectedly, we have come to understand that the human brain is extremely sensitive to social stimuli. Some of the greatest challenges to hard-gained sobriety in addicts come from exposure to former people, places and things – reminders of the addicted states even after many years of sobriety – that then may stimulate a new round of compulsive, addicted behavior; the memories and mental associations are powerful learned re-enforcers of self-destructive behavior.

Different parts of the human brain mature at different rates. The last regions to develop are the frontal regions responsible for cognitive ability, planning, reasoning, decision-making, and other more mature executive functions. The common observation that adolescents’ emotion-driven behavior, daredevil risk-taking, and intergenerational combat may outstrip their ability to reason is borne out in the functional MRI’s and the CT scans of adolescent brain research. The fact that many brain-based disorders, such as schizophrenia, bipolar disorder, and drug-addiction appear to have their usual origins in adolescence, carries profound implications for prevention efforts and early and novel (perhaps gene-focused) treatments, in times to come.

The brain reward-system or pleasure-system is implicated in the evolution of all addictions, chemical as well as behavioral; the neurotransmitter dopamine is the primary chemical messenger associated with this brain function, in health and disease. Different substances, “uppers” or “downers”, amphetamines, heroin or oxycontin, may affect one part or another of the brain-reward system, but they all have a “final common pathway,” as do the behavioral addictions, such as gambling, kleptomania or sex.

We are gradually closing in on many of the prodromal factors that lead to vulnerability to the compulsive behavior we call “addiction,” whether it be multiple genetic factors, and/or environmental factors such a chronic stress or combat horrors.

Unfortunately, according to Alan I. Leshner, MD, former director of the National Institute on Drug Abuse, once the brain’s neural machinery has been “high-jacked” in the vulnerable individual, it becomes very difficult for him to reverse it on his own. Also, his overall adaptability and creativity become compromised. The analogy is with the stroke patient or accident victim learning to walk again or speak again: it is possible to regain a great deal of function but it is not as smooth or sure-footed as the original function.

Likewise, in Addiction Medicine, with our current tools, there needs to be constant vigilance about relapse, as the former addict-oriented brain pathways can become easily reactivated. Another useful analogy: the addicted brain, even long sober, exposed to one of the external stimuli (persons, places, things) or even thinking about them (internal) is like having the automobile accelerator getting stuck and at the same time, the brakes fail.

Reframing Addiction

In the past fifty years, the understanding of addiction has shifted mainly from criminal or moral failing, to a medical illness framework. However, the definition continues to be beset with bias, misconception and lack of precision. One of the major stumbling blocks has evolved from Dr. E.M. Jellinek’s original formulations of alcoholism in 1960 which postulated physical withdrawal symptoms as a bedrock definition for the disease theory of alcoholism.

Since then, there has been controversy over the biological versus psychological basis for addiction, in general. Is it a problem of brain chemistry or willpower, physical vs. mental, biology or behavior? Over the years, funding for research and large arrays of treatment alternatives have focused on one side of this question or the other.

Modern research informs us that it is not an either/or proposition.”

In fact, addiction is a brain disease with biopsychosocial components. Although we are closing in on specific individualized treatments, we are still a long way from identifying specific genetic vulnerability and altering dysfunctional brain patterns and pathways. However, we have learned that the “high-jacked” brain responds positively to integrated treatment that takes into account the distortions of cognitive functioning, the emotional vulnerabilities, as well as physical damage to the brain which takes a long time to heal.

Addiction is a chronic, recurring condition which requires long-term management approaches, with the level of our present knowledge base, as in diabetes or hypertension — more biological focus in the acute stage, more cognitive and emotional supports and psychopharmacology at later stages, but with full awareness of the biopsychosocial nature of the brain disease we call “addiction.”

We have come a long way with discoveries since the “Decade of the Brain”, occurring on a regular basis now with newer understanding of brain plasticity, and bringing us ever closer to our goal of definitive help for our addicted patients.

Interested in learning more about addiction? Let us know in the comments section below or click below to speak with a counselor.

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References:
1. Holtmaat A, Svoboda K. “Experience-Dependent Structural Synaptic Plasticity in the Mammalian Brain.” Nature Rev Neurosci. 2009; 10 (9): 647 – 658.
2. Minervini I, Palandri S, et al. “Desire and Coping Self-Efficacy as Craving Measures in Addiction.” Open Behav Sci Jl. 2011; 5: 1 – 7.
3. Berke JD, Hyman SE. “Addiction Dopamine and the Molecular Mechanisms of Memory.” Neuron. 2000; 25: 515 – 532.
4. Leshner AI. “Science-Based Views of Drug Addiction and Its Treatment.” JAMA. 1999; 282: 1314 – 1316.
5. McLellan AT, Lewis DC, O’Brien CP, Kleber HD. “Drug Dependence, a Chronic Medical Illness.” JAMA. 2000; 284: 1689 – 1695.

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