DRUG-INDUCED PSYCHIATRIC DISEASE

DRUG-INDUCED PSYCHIATRIC DISEASE

  Psychiatric disease is a disease related to the inability of our mental or specifically our brain to function normally. Scientifically, it is known as the mental health problem that interferes with the way a person behaves, interacts with others, and functions in daily life.  The recognition and understanding of mental health problems have changed over time and across cultures, and there are still variations in the definition, assessment, and classification of mental disorders, although standard guideline criteria are widely accepted. Psychosis is a generic psychiatric term for a mental state often described as involving a "loss of contact with reality". It is given to the more severe forms of psychiatric disorder, during which hallucinations and delusions and impaired insight may occur.

      Symptoms of psychiatric disorders rarely occur suddenly. In most cases, symptoms develop over time. Close friends and family members of people with psychiatric disorders may realize that something is wrong or not quite right before the disorder itself is recognized. General symptoms of this disease include hallucinations, delusions, or a thought disorder. Difficulties with concentration, memory, or logical thought and speech, apathy or loss of initiative or desire to participate in any activity that was previously enjoyable including sex as well as dramatic sleep and appetite changes are the major and initially occurred symptoms. Besides, a patient may develop fear or suspiciousness of others or a persistent, strong nervous feeling and rapid or dramatic shifts in feelings or mood swings. All of these symptoms then will give rise to the abnormal behavioral and deterioration of personality. In patient the  chronic cases, the patient may undergo severe changes in mental status, such as delirium or extreme agitation, serious disturbances in perceptions (hallucinations), severe changes in mood, thoughts or behavior and suicidal, threatening or violent actions or behavior.

 There are many categories of psychiatric disorders listed by the psychiatrists including anxiety disorders, delirium, dementia, amnesia, mood disorders, personality disorders, sleep disorders, schizophrenia, delusional disorder, chronic hallucinatory psychosis and others. Psychiatrists also recognized the underlying causes of the psychiatric diseases. Mental health experts believe that psychiatric disorders result from a combination of genetic or inherited dispositions and a triggering event. Genetic causes includes having a parent with a psychiatric disorder while triggering event or acquired causes include external or environmental factors, such as poverty, poor nutrition, overcrowding, neglect and unsatisfactory relationships, especially within the family. Drug abuse and trauma, either physical or mental are also the triggering events leading to psychotic symptoms. However, in this assignment, the concern will be given to the psychiatric diseases that are related to drugs.

 Amphetamines are the major group of drugs that contribute a lot to the development of the psychiatric disorders. These drugs actually lead to the some of the psychiatric diseases like amphetamine-induced mood disorder, amphetamine-induced sleep disorder, amphetamine-induced psychotic disorder with delusions, amphetamine-induced psychotic disorder with hallucinations, amphetamine intoxication delirium and others amphetamine-induced psychiatric disorders. Pharmacologically, amphetamines are used to treat attention deficit hyperactivity disorder (ADHD), narcolepsy, weight loss and some depression as they are grouped as the stimulant drugs and produces increased wakefulness and focus in association with decreased fatigue and appetite. However, because of their addicting potential, these drugs are no longer used for weight loss. 3,4-methylenedioxymethamphetamine (MDMA) or ecstasy, cathinone, and methcathinone are the common types of amphetamines but ecstasy becomes much more popular especially among the teenagers. Another amphetamine derivative which is popular in Malaysia nowadays is methamphetamine or “Pil Kuda”.  Amphetamine-related psychiatric disorders are conditions resulting from intoxication or long-term use of amphetamines or amphetamine derivatives. Such disorders can also be experienced during the withdrawal period from amphetamines. The disorders are often self-limiting after cessation, though, in some patients, psychiatric symptoms may last several weeks after discontinuation. Some individuals experience paranoia during withdrawal as well as during sustained use. Amphetamine use may elicit or be associated with the recurrence of other psychiatric disorders. People addicted to amphetamines sometimes decrease their use after experiencing paranoia and auditory and visual hallucinations. Furthermore, amphetamines can be psychologically but not physically addictive. The pathophysiology(development) of amphetamine-related psychiatric disorders is difficult to establish, because amphetamines influence multiple neural systems. In general, chronic amphetamine abuse may cause psychiatric symptoms due to inhibition of the dopamine transporter in the striatum and nucleus accumbens. The longer the duration of use, the greater the magnitude of dopamine reduction. Methamphetamine has been suggested to induce psychosis through inhibiting the dopamine transporter, with a resultant increase in dopamine in the synaptic cleft. Amphetamine-induced psychosis often results after increased or large use of amphetamines, as observed in binge use or after protracted use. Prescription amphetamines induce the release of dopamine in a dose-dependent manner; low doses of amphetamines deplete large storage vesicles, and high doses deplete small storage vesicles. This increase in dopaminergic activity may be causally related to psychotic symptoms because the use of D2-blocking agents (eg, haloperidol) often ameliorates these symptoms. Amphetamine-induced psychosis has been used as a model to support the dopamine hypothesis of schizophrenia, in which overactivity of dopamine in the limbic system and striatum is associated with psychosis. However, negative symptoms commonly observed in schizophrenia are relatively rare in amphetamine psychosis. Delirium caused by amphetamines may be related to the anticholinergic activity. 

Psychiatric diseases also develop from the use of cocaine. Cocaine is a naturally occurring alkaloid found within the leaves of a shrub, Erythroxylon coca. The name comes from "coca" in addition to the alkaloid suffix -ine, forming cocaine. It is a stimulant of the central nervous system, an appetite suppressant, and a topical anesthetic. Specifically, it is a serotonin–norepinephrine–dopamine reuptake inhibitor, which mediates functionality of these neurotransmitters as an exogenous catecholamine transporter ligand. Because of the way it affects the mesolimbic reward pathway, cocaine is addictive. Cocaine may be abused through a number of different routes. The most widespread routes of administration include inhaling (snorting), subcutaneous injection (skin popping), intravenous injection (shooting-up), and smoking (freebasing or smoking crack). Prolonged use and cocaine abuse may lead to psychiatric disorders like cocaine intoxication delirium, cocaine-induced psychotic disorder with delusions, cocaine-induced psychotic disorder with hallucinations and cocaine-induced mood disorder. Cocaine has a number of pharmacologic effects on the human body. Neuronal fast sodium channel blockade produces a local anesthetic effect that continues to be used in medicine today. During myocardial fast sodium channel blockade, cocaine blocks fast cardiac sodium channels, which results in type I antidysrhythmic activity. This may lead to prolongation of the QRS complex and contribute to the induction of the dysrhythmias associated with cocaine use. Blockade of catecholamine reuptake (ie, norepinephrine, dopamine, and serotonin reuptake blockade) occurs in both the central and peripheral nervous systems. Blockade of reuptake of norepinephrine leads to the sympathomimetic syndrome associated with cocaine use. This syndrome consists of tachycardia, hypertension, tachypnea, mydriasis, diaphoresis, and agitation. Inhibition of dopamine reuptake in the CNS synapses, such as in the nucleus accumbens, contributes to the euphoria associated with cocaine. Norepinephrine release augments norepinephrine reuptake blockade effects. 

Phencyclidine is another group of drug that can cause psychiatric diseases following the prolonged use or abuse. Phencyclidine (a complex clip of the chemical name 1-(1-phenylcyclohexyl)piperidine), commonly initialized as PCP and known colloquially as angel dust, is a recreational dissociative drug. Formerly used as an anesthetic agent, PCP exhibits both hallucinogenic and neurotoxic effects. Unfortunately, it then became a drug of abuse for a small but significant population, mostly younger in age and of minority ethnicity. PCP has been studied in animal models of schizophrenia. More recently, PCP-like compounds have been investigated for use in treating brain ischemia. PCP is known to produce a syndrome in previously nonpsychiatrically ill humans that is similar to schizophrenia and can worsen the psychotic symptoms in people who have a schizophrenic or other psychotic illness. PCP is an N-methyl-D-aspartate (NMDA) antagonist; thus, it blocks the action of glutamate and aspartate, excitatory amino acid CNS neurotransmitters. PCP is also highly anticholinergic in nature. PCP is a sympathomimetic dissociative anesthetic. "Dissociative" means that the user feels that his or her mind is separated or "dissociated" from the body. This can be a very upsetting experience for some people, especially first-time users who are not expecting it. PCP is often classified with the hallucinogens; however, because it can also act a stimulant or even a CNS depressant, it is usually classified separately from all other street drugs. 

Other than that, psychiatric diseases may also be caused by the use of hallucinogens. Hallucinogens are a diverse group of drugs that cause an alteration in perception, thought, or mood. Hallucinogens may be grouped by structural criteria. The main groups include lysergamides, phenylethylamines, piperidines, indolealkylamines, and cannabinols. Lysergic acid diethylamide (LSD) one of the hallucinogens acts on serotonin and dopamine receptors in the brain. The neurotransmitter serotonin modulates mood, pain, perception, personality, sexual activity, and other functions. The hallucinogenic activity of LSD is thought to be mediated by LSD's effect on serotonin-2 receptors. LSD acts postsynaptically to inhibit serotonin release and increase retention of serotonin at serotonin-2 receptors. Its net effect is that of a serotonin agonist. A transient depression may occur after LSD use. Acute psychosis after LSD use has been reported, and an underlying or undiagnosed schizophrenia may worsen. An unusual aspect of LSD use is the occurrence of "flashbacks," or hallucinogen persisting perception disorder (HPPD), months to years after LSD use. These are observed most commonly in persons who have used LSD more than 10 times. During a psychotic episode, danger of suicide and homicide exists.

Schizophrenia is another class of psychiatric disease that results from consumption of drug; cannabis or marijuana. Schizophrenia is a severe mental illness which may cause someone to hear voices in his head and believe that other people are trying to control or harm him. Research shows a link between cannabis and people with schizophrenia. It is possible that if you have a pre-existing risk which you may not be aware of, there is a much higher chance that using cannabis will trigger an episode of schizophrenia – increasing risk by between 50% - 200%. These risks are also greater in younger people who use cannabis and those that smoke it more regularly. The tendency of a person to get schizophrenia is much higher if he has any family history of mental illness, had an episode of paranoid thinking or hearing voices or had a bad response when first using cannabis or when using a small amount.  Using cannabis as a teenager may be a risk to many aspects of your mental health. One of the compounds is cannabis – THC (tetrahydrocannabinoid) – gets you ‘high’. THC is very similar to endocannabinoids which are naturally found in your brain. These regulate other chemicals that control many aspects of your brain function and behavior. Because THC is so similar, it can mimic the effects of these natural compounds and take over these aspects of your brain function. The long-term effects of using cannabis in your teens may be caused by the influence of THC on your brain’s chemical systems at a time when your brain is still developing. Cannabis impacts on neurotransmitters that regulate how arousal and stress are managed in the brain. Cannabis takes a long time to metabolize, and can quickly build up to high levels in the body. Once you get to this point, there is a real risk of depression or schizophrenia being triggered. Many of these research studies indicate that the risk is higher when the drugs are used by people under the age of 21, a time when the human brain is developing rapidly and is particularly vulnerable. 

Antipsychotics are group of drugs used to manage, reduce and even treat psychosis symptoms and the psychiatric diseases. Antipsychotics are broadly divided into two groups, the typical or first-generation antipsychotics and the atypical or second-generation antipsychotics. The typical antipsychotics are classified according to their chemical structure while the atypical antipsychotics are classified according to their pharmacological properties. These include serotonin-dopamine antagonists, multi-acting receptor-targeted antipsychotics (MARTA, those targeting several systems), and dopamine partial agonists, which are often categorized as atypical. A first generation of antipsychotics, known as typical antipsychotics, was discovered in the 1950s. Most of the drugs in the second generation, known as atypical antipsychotics, have been developed more recently, although the first atypical antipsychotic, clozapine, was discovered in the 1950s and introduced clinically in the 1970s. Both generations of medication tend to block receptors in the brain's dopamine pathways, but antipsychotic drugs encompass a wide range of receptor targets. Common conditions with which antipsychotics might be used include schizophrenia, bipolar disorder and delusional disorder. Antipsychotics might also be used to counter psychosis associated with a wide range of other diagnoses, such as psychotic depression. Antipsychotics are associated with a range of side effects. It is well-recognized that many people stop taking them (around two-thirds even in controlled drug trials) due in part to adverse effects. Extrapyramidal reactions include acute dystonias, akathisia, Parkinsonism (rigidity and tremor), tardive dyskinesia, tachycardia, hypotension, impotence, lethargy, seizures, intense dreams or nightmares, and hyperprolactinaemia. Side effects from antipsychotics can be managed by a number of different drugs. For example, anticholinergics are often used to alleviate the motor side effects of antipsychotics. Some of the side-effects will appear after the drug has been used only for a long time.