Methamphetamine: Difference between revisions

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===Dependence and abuse potential===

As with other [[stimulant]]s, the chronic use of methamphetamine can be considered [[Addiction potential::extremely addictive with a high potential for abuse]] and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and [[withdrawal effects]] may occur if a person suddenly stops their usage.

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In highly dependent [[amphetamine]] and methamphetamine abusers, "when chronic heavy users abruptly discontinue methamphetamine use, many report a time-limited withdrawal syndrome that occurs within 24 hours of their last dose".<ref>Treatment for amwithdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> Withdrawal symptoms in chronic, high-dose users are frequent, occurring in up to 87.6% of cases, and persist for three to four weeks with a marked "crash" phase occurring during the first week.<ref>Treatment for amphetamine withdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> Methamphetamine withdrawal symptoms can include anxiety, drug craving, dysphoric mood, fatigue, increased appetite, increased movement or decreased movement, lack of motivation, sleeplessness or sleepiness, and vivid or lucid dreams.<ref>Treatment for amphetamine withdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> Withdrawal symptoms are associated with the degree of dependence (i.e., the extent of abuse).<ref>Treatment for amphetamine withdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> The mental depression associated with methamphetamine withdrawal lasts longer and is more severe than that of [[cocaine]] withdrawal.<ref>Methamphetamine abuse (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/17990840</ref>

Although it is clear that vaporised methamphetamine is more addictive than oral or insufflated amphetamine, there is debate as to whether the drug itself is inherently more addictive, and if so, how important the difference is. Besides the duration of action, the main difference between the two drugs is that methamphetamine is proportionally more centrally and less peripherally active. One reason is because the increased lipid solubility of the methyl group causes faster central absorption. Another cause is the fact that methamphetamine releases proportionally more dopamine at an equivalent dose. D-methamphetamine releases a dopamine:norepinephrine ratio of ~1:1.3 from synapses versus ~1:2 for d-amphetamine.<ref>https://en.wikipedia.org/wiki/Monoamine_releasing_agent#Activity_profiles</ref> Their effect on the norepinephrine (NET) and dopamine (DAT) transporters are more alike but there is a slight difference. D-methamphetamine favours NET by a factor of about 4 vs 5 for d-amphetamine. D-methamphetamine is also slightly more serotonergic. This may be a negligible difference, as the ratio of serotonin:norepinephrine release is only 1:60 for d-methamphetamine and 1:80 for d-amphetamine. Neither drug has any appreciable affinity for the serotonin transporter (SERT).

This increased central vs peripheral effect of methamphetamine agrees with the common subjective feeling among stimulant users that the methamphetamine high has less of an inherently 'jittery' quality to it. The downside is that this aversive effect may be helpful as it discourages harmful levels of use. It is unclear what real world impact this difference has. A double-blind but small study of 13 methamphetamine users revealed only a minor preference towards methamphetamine, and this may be explained by the users having a greater familiarity with the drug.<ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3475187/</ref>

It is strongly recommended that one use [[responsible drug use|harm reduction practices]] when using this substance.

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 ===Dependence and abuse potential===
 As with other [[stimulant]]s, the chronic use of methamphetamine can be considered [[Addiction potential::extremely addictive with a high potential for abuse]] and is capable of causing psychological dependence among certain users. When addiction has developed, cravings and [[withdrawal effects]] may occur if a person suddenly stops their usage.
@@ Line 142: / Line 143: @@
 In highly dependent [[amphetamine]] and methamphetamine abusers, "when chronic heavy users abruptly discontinue methamphetamine use, many report a time-limited withdrawal syndrome that occurs within 24 hours of their last dose".<ref>Treatment for amwithdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> Withdrawal symptoms in chronic, high-dose users are frequent, occurring in up to 87.6% of cases, and persist for three to four weeks with a marked "crash" phase occurring during the first week.<ref>Treatment for amphetamine withdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> Methamphetamine withdrawal symptoms can include anxiety, drug craving, dysphoric mood, fatigue, increased appetite, increased movement or decreased movement, lack of motivation, sleeplessness or sleepiness, and vivid or lucid dreams.<ref>Treatment for amphetamine withdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> Withdrawal symptoms are associated with the degree of dependence (i.e., the extent of abuse).<ref>Treatment for amphetamine withdrawal (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/19370579</ref> The mental depression associated with methamphetamine withdrawal lasts longer and is more severe than that of [[cocaine]] withdrawal.<ref>Methamphetamine abuse (PubMed.gov / NCBI) | http://www.ncbi.nlm.nih.gov/pubmed/17990840</ref>
+Although it is clear that vaporised methamphetamine is more addictive than oral or insufflated amphetamine, there is debate as to whether the drug itself is inherently more addictive, and if so, how important the difference is. Besides the duration of action, the main difference between the two drugs is that methamphetamine is proportionally more centrally and less peripherally active. One reason is because the increased lipid solubility of the methyl group causes faster central absorption. Another cause is the fact that methamphetamine releases proportionally more dopamine at an equivalent dose. D-methamphetamine releases a dopamine:norepinephrine ratio of ~1:1.3 from synapses versus ~1:2 for d-amphetamine.<ref>https://en.wikipedia.org/wiki/Monoamine_releasing_agent#Activity_profiles</ref> Their effect on the norepinephrine (NET) and dopamine (DAT) transporters are more alike but there is a slight difference. D-methamphetamine favours NET by a factor of about 4 vs 5 for d-amphetamine. D-methamphetamine is also slightly more serotonergic. This may be a negligible difference, as the ratio of serotonin:norepinephrine release is only 1:60 for d-methamphetamine and 1:80 for d-amphetamine. Neither drug has any appreciable affinity for the serotonin transporter (SERT).
+This increased central vs peripheral effect of methamphetamine agrees with the common subjective feeling among stimulant users that the methamphetamine high has less of an inherently 'jittery' quality to it. The downside is that this aversive effect may be helpful as it discourages harmful levels of use. It is unclear what real world impact this difference has. A double-blind but small study of 13 methamphetamine users revealed only a minor preference towards methamphetamine, and this may be explained by the users having a greater familiarity with the drug.<ref>https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3475187/</ref>
 It is strongly recommended that one use [[responsible drug use|harm reduction practices]] when using this substance.