Crystal meth, known formally as methamphetamine, is an extremely powerful psychostimulant drug and is a member of the amphetamine family. It is one of the most potent stimulants known and can produce extreme euphoria, heightened alertness, increased confidence, powerful sexual urges, and gives the user an almost overwhelming amount of energy. Its danger comes not only from its potency but also from the fact that it is very cheap and widely available.
How Meth Affects The Brain
Meth produces extremely potent neurological effects, which over time can actually physically change the way the brain is wired and operates. The main mechanism of action meth produces is on dopamine function, however serotonin and norepinephrine function are also modified greatly. There is a surge of all 3 neurotransmitters, but dopamine function is altered much more comprehensively. While amphetamines typically produce their effects by indirect means through stimulation of neurotransmitter release and inhibiting their reuptake, meth acts in a much more intense way by more strongly stimulating neurotransmitter release as well as inhibiting reuptake, promoting the release of stored dopamine, and causing reverse transport in the dopamine receptors themselves¹. It has also been hypothesized that meth can act as a “false transmitter” which means that it directly causes stimulation of dopamine receptors, instead of simply causing dopamine release¹.
Because of the constant flood of these 3 neurotransmitters, the brain will begin to reduce its own response to these chemicals in an attempt to maintain balance. This process is known as downregulation. Since these neurotransmitters are present in such huge numbers, the brain adapts by reducing the number of receptors to avoid excitotoxicity. In this way, tolerance to meth is produced. The brain is less sensitive to these neurotransmitters, thus requiring more of them to produce the same effect. Additionally, once downregulation has occurred, the brain is unequipped to operate normally without the high levels produced through meth use. This has the effect of a user feeling more and more depressed, anxious, and uncomfortable the longer they use meth.
Finally, meth has known long term effects on brain structure and function. Similar to downregulation, the brain has certain specialized areas that are very strongly affected by meth use. The striatum and the ventral tegmental area are 2 such areas which have far-reaching consequences as far as higher-level behavior is concerned. These are both parts of the limbic system, which is sometimes referred to as the “reward center” of the brain. As its name implies, it is responsible for feelings of behavior-related reward, positive reinforcement, motivation, and plays a role in fine motor control. Meth induced changes to the limbic system as a whole and these 2 areas, in particular, is known to worsen addictive behavior, reduce empathy for others, and increase risk-taking behavior in general.
The sensory effects of meth are produced mainly through a surge in both dopamine and norepinephrine. The euphoria and rush of pleasure felt from meth use is mainly due to dopamine. This is a feeling of excited bliss which is very intense and sudden in onset. While dopamine function is more strongly stimulated, the most pronounced sensory effects are due to norepinephrine. This is both a neurotransmitter and a hormone when it is present in the blood and has very far-reaching effects.
In the brain, norepinephrine is responsible for attention and focus, confidence, and aggression, and can increase sexual arousal. Additionally, excess levels of norepinephrine can speed up thought processes and the feeling of importance attached to these thoughts. A meth user will simultaneously have thoughts racing through their head while feeling like they can, and must, accomplish every single one of them. A sense of omnipotence and supreme confidence in one’s ability is common. This is responsible for many meth addicts getting into serious trouble for attempting things which to a sober person sound completely impossible and ridiculous.
Meth has some very serious effects on the emotional states of users. In the long term, this is expressed as a permanent decrease in the ability to feel empathy or to sympathize with other people. In the short term, this manifests as a disregard for other people while under the influence of meth. The euphoria and increased energy promote a very intense desire to stay this way, and the severe depression felt when users are not under the influence can promote anxiety regarding the ability to get or use more meth.
The depression felt when not using meth will only increase the longer meth is used, as dopamine downregulation deepens with further use. This can create or worsen any preexisting mental issues related to depression, and take many years of abstinence to fully recover from. Likewise, meth users become more prone to wild mood swings between feelings of hopelessness to giddy ecstasy, and this extreme emotional pendulum effect can have an overall negative effect on the state of mind of a user. Additionally, extreme insomnia which frequently accompanies meth use has a very negative psychological impact. This can increase paranoia and delusional thoughts and feelings, furthering the user’s detachment from reality.
Meth use can be characterized by excessive energy and talkativeness, insomnia, paranoia, and excessive fidgeting or tics such as pulling hair or picking of the face and arms. Excessive use may also result in psychotic-like states which typically present as a paranoid or delusional hyperactive state which frequently involves violent outbursts. The protracted insomnia characteristic of chronic use also contributes to the psychotic states and overall degradation of physical and mental health.
Since someone using meth is sleeping much less, they will commonly begin associating with others who are likewise insomniac. This usually means socializing with other tweakers (meth users) for the most part. This commonly increases meth use since there is a gradual withdrawal from normal society, including friends, family, and coworkers. As the need for meth will increase, as does a user’s tolerance, criminal behavior is frequently the result. Once a user has spent all of their money, they will go to any lengths to get more money for meth. This usually ends badly, the best-case scenario being in the back of a police car.
In general, some behaviors which may appear during meth use include:
- Withdrawal from Family and Social Life
- Increased Absences from Work
- Erratic or Unusual Behavior
- Failure to Keep Plans
- Frequent Appeals to Borrow Money
- Decreased Emphasis on Personal Hygiene
Immediate Neurological Effects of Meth Use
Once meth has been used, it will rapidly enter the brain and cause an intense surge of the neurotransmitters dopamine, norepinephrine, and serotonin. These are all neurotransmitters that mediate signals in the brain and have different effects depending on where in the brain they are released, and at what levels. Some of the most general neurological effects include a speeding up of thought processes, an increase in confidence and awareness, and a feeling of intense euphoria.
- Dopamine is used in the brain, in part, to affect the feelings related to reward and motivation. In this way, the huge surge produced when using meth can help create the rush of euphoria and increase the desire to experience this again. Meth’s most powerful effect is on dopamine where it not only increases the levels which are secreted but also prevents dopamine reuptake and also releases dopamine which is stored inside neurons, causing levels to rise dramatically (some say in the 100’s-1000’s of percent range). Meth induced dopamine release is also known to change the way the brain is wired in very profound ways. Two areas most heavily affected are the ventral and dorsal striatum; both areas of which are known to play an important role in drug addiction specifically, and addictive behavior in general.
- Norepinephrine is both a neurotransmitter as well as a hormone when it is present in the blood, and is a huge component of the “fight-or-flight” response. In the brain, it acts to increase alertness, confidence, aggression, and can speed up mental reaction time. In the body, it acts as a stress hormone and promotes the release of glucose, increases heart rate and blood pressure, and increases blood flow to muscles. Normally, this chemical is released in bulk during fight-or-flight situations since it can raise physical performance for brief periods, increasing survival chances. This increase in physical ability is worrying in the case of a meth user having the ability (however briefly) to feel that they are able to accomplish the dizzying array of thoughts that are rushing through their mind.
- Serotonin is used as a mood enhancer and regulator, and helps promote feelings of well being and happiness. The flood produced by meth use is overwhelming and is partially responsible for the euphoria as well as the sense of fulfillment achieved through using meth. Using meth for even a short time can disrupt the brains normal response to serotonin, and can enforce the desire to do more meth. In this way, the user will quickly begin to feel depressed when they aren’t high, and this effect will increase the longer meth is used.
The subjective effects that a user will feel include a huge rush of energy and euphoria, a feeling that they are on top of the world, greatly sped up and maybe jumbled thinking, increased sexual urges, and supreme confidence in themselves. This happens very quickly after use and is extremely intense. Someone using meth will feel as if they are seeing the world as it really is for the first time, and that great things are right around the corner for them.
Long Term Neurological Effects of Meth Use
While these physical risks of long-term meth use are scary, the mental and neurological effects are terrifying. Using crystal meth use can drastically alter the structure of the brain, and it is currently unknown if these changes can heal. Just a few of these long term effects include:
- Amphetamine Psychosis (Acute)¹²³: A common result from psychostimulant abuse, but much more widespread with meth use. Symptoms can be indistinguishable from Acute Paranoid Schizophrenia and can include a variety of symptoms such as visual/auditory/tactile hallucinations, paranoid delusions, disorganized thoughts, erratic behavior, and violent outbursts.
- Dementia-Like Symptoms: Some of the ways this can present is as a slowing of mental functions such as comprehension, reaction time, memory, and a greatly increased susceptibility to Parkinsonism. The exact cause is unclear but involves damage to dopamine terminals in the brain. This particular type of brain damage has been shown to improve with prolonged abstinence, however a return to pre-meth brain function is unlikely. The effects meth has on the brain appear to resemble a roughly 4x acceleration of age-related neural degradation¹².
- Increase in Aggression: This is an acute symptom of meth use, but can also be a permanent change to a user’s personality. The exact mechanism is unknown, but damage to serotonin terminals is somehow involved. Studies using PET scans have shown that meth use is directly correlated to decreased serotonin terminal density, and further, that decreased SER terminal density is an indicator for the amount of aggression someone displays. It is currently unknown if, or to what degree, this is reversible¹.
- Increased Anti-Social or Psychopathic Tendencies: This is shown in chronic meth users (rodents and humans) through MRI scans which show enlarged striatal volumes, as well as PET scans which show decreased brain glucose metabolism¹. Lowered brain glucose metabolism is an indicator of decreased or abnormal neurological function¹. The decrease in metabolism was commensurate with the amount used; higher doses of meth produced a greater decrease in brain glucose metabolism. In particular, the presence of increased striatal volumes is noteworthy, as this feature is closely associated with psychopathy and extreme antisocial behavior. On average, diagnosed psychopaths have 9.6% increased Striatal volumes when compared to people who do not exhibit psychopathic tendencies¹.
- Increased Susceptibility to Neurodegenerative Diseases: Due to neuroinflammation, excitotoxicity, and damage to the blood-brain barrier. This also increases the risk for Alzheimer’s, Parkinson’s, various dementias, as well as accelerating the progression of HIV associated dementia and NeuroAIDS¹². There is also the possibility of an increased risk of prion disease¹ such as Creutzfeldt-Jakob (mad cow disease).
- Progress In Neurobiology: Mechanisms of Neurotransmitter Release by Amphetamines – A Review
- The Permanente Journal: The “Party” Drug Crystal Methamphetamine – Risk Factor For The Acquisition of HIV
- Current Drug Abuse Reviews: Mechanism of Action of Methamphetamine within the Catecholamine and Serotonin Areas of the Central Nervous System
- The Journal of Neuroscience: Loss of Dopamine Transporters in Methamphetamine Abusers Recovers with Protracted Abstinence