《Chinese Journal of Drug Dependence》1999-04
Does anyone know what aerosol bioelectricity is?? And why it might be used to treat heroin addiction? The entire literature seems to be in Chinese. I came across that particular paper while searching for others, specifically reports on ablative psychosurgery1 for the treatment of opiate addiction in China (Gao et al., 2003 is the first in English). Hence, the title of the present post is a reference to the book by Elliot Valenstein, Great and Desperate Cures: The Rise and Decline of Psychosurgery and Other Radical Treatments for Mental Illness.
Are there other "unusual" Chinese treatments for addiction, beyond what might be expected (e.g., acupuncture and traditional medicine)? Tetrodotoxin (TTX), a neurotoxin found in puffer fish, is a worthy runner up to aerosol bioelectricity. TTX inhibits action potentials by blocking voltage-dependent sodium channels. It has been tested as a treatment for severe cancer pain, which motivated Shi and colleagues (2009) to compare low dose TTX to placebo in abstinent addicts. After watching a heroin-related video, the group receiving TTX reported lower levels of craving and anxiety, without alterations in heart rate or blood pressure. However, these acute results were from a single session with no long-term follow up.
Although Chinese treatments for internet addiction are getting all the headlines these days, drug addiction is actually a much more serious problem. In their review of the literature, Tang et al. (2006) inform us that:
Historically, China has had extraordinarily high rates of opiate dependence. These rates declined drastically following the 1949 revolution; however, opiate abuse has re-emerged in the late 1980's and has spread quickly since then. ... The number of registered addicts in 2004 was 1.14 million (more than 75% of them heroin addicts), but the actual number is probably far higher. Opiate abuse contributes substantially to the spread of HIV/AIDS in China, with intravenous drug use the most prevalent route of transmission (51.2%). Currently, the main treatments for opiate dependence in China include short-term detoxification with opiate agonists or non-opiate agents, such as clonidine or lofexidine [alpha-2 adrenergic drugs that inhibit norepinephrine release]; Chinese herbal medicine and traditional non-medication treatments are also used. Methadone maintenance treatment (MMT) has not been officially approved by the Chinese government for widespread implementation, but some pilot studies are currently underway.Which brings us back to neurosurgery. But before discussing the results of Gao et al., a quick review. In the last post, we learned about a new and less desperate cure, the application of Deep Brain Stimulation for Severe Alcoholism. The target region in this small clinical trial (n=3) was the nucleus accumbens (NAcc), which has been called a "pleasure center" and "hedonic hot spot" that responds to food and pharmaceutical and financial and sexual rewards. The idea behind NAcc DBS was to reduce alcohol craving and "incentive sensitization" in severely impaired patients who had failed multiple treatments (Heinze et al., 2009). The researchers drew upon the experimental and theoretical work of Berridge and colleagues (2009) distinguishing between the "wanting" (incentive salience) and "liking" (hedonic impact) aspects of reward:
Usually a brain ‘likes’ the rewards that it ‘wants’. But sometimes it may just ‘want’ them. Research has established that ‘liking’ and ‘wanting’ rewards are dissociable both psychologically and neurobiologically. By ‘wanting’, we mean incentive salience, a type of incentive motivation that promotes approach toward and consumption of rewards, and which has distinct psychological and neurobiological features."Liking" has been strongly linked to endogenous opioid systems in the NAcc and ventral pallidum [part of the globus pallidus] as shown below.2
From Fig. 1 (Berridge et al., 2009). Forebrain hedonic hotspots in nucleus accumbens shell and in ventral pallidum where mu opioid agonist microinjections cause amplification of ‘liking’ reactions to sweetness. Red/yellow indicates greatest amplification of ‘liking’ for the sensory pleasure.
In contrast, "wanting" has been most strongly associated with dopamine in the NAcc, but in reality...
...brain substrates for ‘wanting’ are more widely distributed and more easily activated than substrates for ‘liking’. Neurochemical ‘wanting’ mechanisms are more numerous and diverse in both neurochemical and neuroanatomical domains... In addition to opioid systems, dopamine and dopamine interactions with corticolimbic glutamate and other neurochemical systems activate incentive salience ‘wanting’. Pharmacological manipulations of some of those systems can readily alter ‘wanting’ without changing ‘liking’. For example, suppression of endogenous dopamine neurotransmission reduces ‘wanting’ but not ‘liking’.Addiction is conceived as a process by which drugs of abuse produce neural sensitization and compulsive "wanting" even in the absence of "liking". With this literature in mind, Gao et al. (2003) wished to:
...explore a new way of treating drug addiction by ablating the NAcc... using stereotactic surgery, blocking the mesocorticolimbic dopamine circuit, alleviating craving for drugs and lowering the relapse rate after detoxification. On the basis of animal experiments, stereotactic surgery was performed in 28 patients by making a lesion in the NAcc bilaterally to treat opiate drug dependence.I'm not so sure the surgeons were able to isolate the "wanting" from the "liking" regions of the NAcc, since they seem to be anatomically adjacent as shown below.
Fig. 2 (Berridge et al., 2009). Expansion of mu opioid hotspot in nucleus accumbens with delineation of ‘liking’ versus ‘wanting’ zones. Green: the entire medial shell mediates opioid-stimulated increases in ‘wanting’ for food reward. Orange-red: circumscribed cubic-millimeter sized hedonic hotspot generates increases in ‘liking’ after the same opioid stimulation. Blue: a small hedonic ‘coldspot’ suppresses ‘liking’ reactions to sucrose, whereas a larger purple zone suppresses ‘disliking’ reactions to quinine.
Were the surgeries successful? Not so much:
The mean follow-up period was 15 months. Relapse has not occurred in 11 cases up till now. Drug-free time in these patients has been more than half a year in 4 cases (more than a year in 3 cases), and less than half a year in 7 cases. Relapse occurred in 15 cases after surgery. Drug-free time in these patients was more than half a year in 3 cases, between 1 month and half a year in 10 cases and less than 1 month in 2 cases.Plus there were side effects in some patients: personality changes were seen in 2 and temporary memory loss in 4. Last but not least was the issue of informed consent, which wasn't discussed at all in the paper. Alarmingly, the psychological state of the patients before surgery seems to suggest they lacked capacity to give informed consent:
Analysis of the results showed that the patients’ psychohygienic situation was poor prior to the operation and their personalities were characterized by unstable emotion, being seriously distressed by tonicity and prone to following their own course, running risks and doing everything without considering the consequences, paranoid state, low intelligence level, mental aberration and weak-willedness.In comparison, the careful screening procedures of Heinze et al. (2009) and the reversible nature of their intervention are vastly superior. Comments on my previous post have ranged from unbridled enthusiasm for DBS 3 (also see Best Before Yesterday) to skepticism ("We still have no idea whether this will
1 Wikipedia warns us that "The medical procedure of psychosurgery should not be confused with psychic surgery — surgery purportedly performed by paranormal means."
2 "Liking" has also been associated with endocannabinoid and GABAA-benzodiazepine systems in the brain.
3 For more information on DBS for intractable depression, see The Neurocritic's archival posts:
Berridge KC, Robinson TE, Aldridge JW. (2009). Dissecting components of reward: 'liking', 'wanting', and learning. Curr Opin Pharmacol. 9:65-73.
Gao, G., Wang, X., He, S., Li, W., Wang, Q., Liang, Q., Zhao, Y., Hou, F., Chen, L., & Li, A. (2003). Clinical Study for Alleviating Opiate Drug Psychological Dependence by a Method of Ablating the Nucleus accumbens with Stereotactic Surgery. Stereotactic and Functional Neurosurgery, 81 (1-4), 96-104 DOI: 10.1159/000075111
Heinze, H. et al. (2009). Counteracting incentive sensitization in severe alcohol dependence using deep brain stimulation of the nucleus accumbens: clinical and basic science aspects. Frontiers in Human Neuroscience, 3.
Shi J, Liu TT, Wang X, Epstein DH, Zhao LY, Zhang XL, Lu L. (2009). Tetrodotoxin reduces cue-induced drug craving and anxiety in abstinent heroin addicts. Pharmacol Biochem Behav. 92:603-7.
Tang YL, Zhao D, Zhao C, Cubells JF. (2006). Opiate addiction in China: current situation and treatments. Addiction 101:657-65.
Subscribe to Post Comments [Atom]