Noninvasive human brain imaging studies have shown alterations in the activity of the dopamine system that are associated with reduced motor skills and impaired verbal learning. Recent studies in chronic methamphetamine abusers have also revealed severe structural and functional changes in areas of the brain associated with emotion and memory which may account for many of the emotional and cognitive problems observed in chronic methamphetamine
Extreme use of alcohol and other drugs can damage the brain and can sometimes cause hallucinations or other symptoms of a mental disorder but is only usually caused by excessive use of alcohol and drugs. Another cause for a mental disorder is infection. Infection can lead to the rise of mental illnesses and schizophrenia has been linked to flu. Another physical cause of a mental disorder is the biochemistry including neurotransmitters and hormones. Neurotransmitters are known to have an impact on behaviour such as high levels of nor adrenaline and dopamine are seen when a depressed mood is evident e.g.
These moods and behaviors can lead to social and occupational deterioration ( NIDA “Meth…” ). Methamphetamines also have many physical side effects. The increase in energy Stone 5 and alertness are appealing to many users. Appetite is decreased as well ( ONDCP “Meth…” ). These benefits come at a high cost.
There are many ways Meth can be used, in which include smoked, injected, orally ingested, or snorted. When Meth is smoked or injected it causes more of a rush. When it is snorted or taken orally it produces a longer lasting high instead of a rush, which can continue for as long as twelve hours. Both the rush and the high result from the release of very high levels of dopamine into areas of the brain that regulate feelings of pleasure. This is why people become addicted.
In terms of biochemistry, chemical imbalances in the brain may be involved in certain mental illnesses. Neurotransmitters, for example, play a very important part in behaviour – one theory links depression to low levels of the neurotransmitters serotonin and noradrenaline. However, the relationship between neurotransmitters and depression is very complex and therefore, more research is needed to discover the exact link between this and the disorder. People suffering from depression, also often have high levels of the hormone cortisol. Cortisol is sometimes referred to as a ‘stress hormone’ because it is produced in times of stress.
“Meth causes the blood vessels to constrict; it cuts off the steady flow of blood to all parts of the body. Heavy usage can weaken and destroy these vessels, causing tissues to become prone to damage and inhibiting the body's ability to repair itself.” (Visible Signs, paragraph 1) A really big appearance change that happens when using this drug is the aging process. The body loses the elasticity and luster that causes you to look young in such a short amount of time. Another really bad thing that can happen to your body with all the Methamphetamine use is the hygiene of the mouth. “The drug causes the salivary glands to dry out, which allows the mouth's acids to eat away at the tooth enamel, causing cavities.” (Meth Mouth, second
Researchers believe that, elevated dopamine levels, psychiatric conditions, and being restrained are some of the factors that cause excited delirium. Per Wesley elevated levels of dopamine are the cause of Excited Delirium symptoms. With the increase in dopamine along with the effects of stimulant drugs the body has an increase in metabolic activity that induces hyperthermia. With all the increase in muscle use you have an elevated creatinine phosphokinase from the muscle death causing the patient to become acidotic. Now the patient is hyperkalemic from the metabolic acidosis causing dysrhythmias leading to cardiac arrest.
Stress also increases the heart rate and can lead to the increase of blood pressure, thus Hypertension and can lead to Coronary Heart Disease (CHD). Although this disease can be caused by the indirect effects. Indirect effects of stress are associated with the bad habits that stress causes us to take part in, these included smoking, poor diet and alcohol abuse. These poor habits can thus lead to ill-effects on one’s health. These issues are more related to chronic stress rather than acute stress and it occurs for a long period, thus affecting health for a longer period.
For example, a large person generally needs more of a drug than a smaller person needs for the same effect. Whether people take a drug as instructed also affects their response to it. These factors may affect how the body absorbs the drug, how the body breaks down and eliminates the drug, or what effects the drug has on the body. Because so many factors affect drug response, doctors and pharmacists must choose a drug appropriate for each person and must adjust the dose carefully. This process is more complex if the person takes other drugs and has other diseases, because drug-drug and drug-disease interactions are possible.
Today, caffeine is found in drinking sodas, tea, coffee, chocolate, medicines, energy drinks, and so on. According to Kuhn, Swartzwelder, and Wilson (2003), caffeine falls under the drug class of stimulant. The buzz that is created by caffeine increases euphoria, alertness, and concentration. If caffeine is taken in large amounts, it can cause agitation and nervousness. Also, extreme use of caffeine can cause panic attacks.