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Harms of Drug Use - Coggle Diagram
Harms of Drug Use
Human
Neuropathology
- unclear whether neuropathology stems from:
- the psychoactive ingredient of the consumer compound, adulterants, secondary illnesses, accidents under intoxication, violent assault, and/or self-harm.
- in some cases, etiology has been ascribed to the psychoactive substance itself using animal models.
- neuropathic changes can begin a decline into neuropsychological disorders.
- may help explain the strong comorbidity of protracted drug abuse and psychiatric illness,
nicotine:
- brody et al (2004): MRI to examine the volume and density of grey matter (general term for those parts of the CNS that contain predominantly cell bodies) in the frontal cortex (involved in decision-making, making executive functions, allows us to have adaptive behaviour) in smokers and non-smokers.
- smoking is associated with decreased brain matter volume in the frontal cortex.
- density is also negatively correlated with years of smoking.
- as years of smoking increases, frontal brain volume decreases
heroin
- heroin is associated with a range of neuropathologies (not caused > not enough evidence)
- brain hypoxia (reduced oxygen availability in the brain), cerebral oedema (water saturation), stroke (loss of blood supply to the brain), general loss of white matter (general term for parts of the CNS that contain mostly myelinated axons > dendrites on brain cells), reduced grey matter density in frontal cortex.
- yuan et al (2009): heroin-depedent vs controls:
- reduced grey matter density in the frontal cortex.
- duration of use negatively correlated with grey matter density.
cocaine
- cocaine abuse is associated with premature stroke, seizures, and movement disorders.
- *lim et al (2002): cocaine users vs age-matched controls
- negative correlation between white matter integrity and years of cocaine use > inferior frontal cortex
cannabis
- reduced metabolic activity in the frontal cortex
- yüctel et al (2008): anatomical abnormalities using MRI > 15 long term- heavy cannabis-using men, vs 16 matched non-using controls.
- reduced volume in the hippocampus and amygdala of the cannabis users compared to non-users.
- unlikely that these changes were due to acute cannabis exposure or withdrawal as brain volumes do not fluctuate this way.
- evidence of permanent neuropathology associated with long-term heavy cannabis use.
alcohol
- wernicke encephalopathy is a general reduction in brain tissue.
- krosakoff syndrome is a psychiatric diagnosis characterised by anterograde amnesia (inability to remember new things)
methamphetamine
- strokes and haemorrhae: 2nd most commonn cause in persons < 45 years.
- volkow et al (2001):
- PET (positron emission tomography > an imaging technique that can tell us about how the brain is functioning) following 1 and 14m abstincence.
- compared to controls, meth users showed reduced DAT (dopamine transporters > provides us with an index of damage to dopamine nerve trials) in the striatum at 1 month of abstinence but showed recovery of DAT by 14 months of abstinence
- the level of recovery was less in meth abusers with a longer history of use.
General
types of harm
- medical: organ damage, neurotoxicity, infections, fetal exposure, dependence, injuries
- social: relationships, low education, violence, accidents, criminality, the burden on health system/resources.
- economic: poor occupational attainment, poverty, cost to employers, homelessness, cost to healthcare.
burden of disease
- WHO = agency of the UN > concerned with international public health > collate data on the global extent of drug use.
- WHO estimates the burden of disease produced by addictive substances. the estimation is based on:
- prevalence and exposure
- proportion of "problem users"
- disease categories that have been causally linked to the use of the substance through epidemiological and experimental studies (e.g. alcohol > foetal alcohol syndrome, heart disease, cancer, etc.
metrics
- burden of disease analysis is a technique used by the WHO to assess and compare the impact of different diseases, conditions, or injuries and risk factors on a population.
- uses information from a range of sources to quantify the fatal and non-fatal effects of diseases in a summary measure of health called disability-adjusted life years (DALY).
- WHO uses three metrics to report disease burden:
- years lived in ill-health or with disability (YLD): number of total years of healthy life lost from disease and injury that is attributed to the substance (non-fatal burden)
- years of life lost (YLL): estimates of years of life lost by premature death as a result of a substance (fatal burden)
- disability-adjusted life years (DALY): a summary measure (in years) of healthy life lost, either through premature death (YLL) or through living with ill health due to illness or injury (YLD)
- also see mortality (number of deaths) being used.
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Education
- poorer educational attainment
- clear evidence of an association between drug use and poorer educational attainment (macleod et al 2004)
- drug use typically starts in adolescence > either during the school period or sometime after
- drugs may cause poorer educational attainment by:
- producing a behavioural disorder
- de-motivation
- adoption of cultural values
- occupying study time.
- poorer education may cause drug use because:
- individuals who are failing at school have less incentive to concentrate on their studies, so they allocate more time to leisure.
- selling drugs may be an attractive alternative to a low-level job
drug use and poorer educational attainment may be reciprocally causal in that they promote each other:
- de-motivation + more leisure time = drug use
drug use and poorer educational attainment may be caused by a third variable (impulsive personality, IQ, etc)
- macleod et 2004: the association between drug use and poorer education attainment was insignificant once a third variable (antisocial/problematic behaviour) was considered.
- this analysis suggests that drug use does not cause poorer educational attainment, but rather, broader interpersonal or psychological disorders independently drive both.
Occupation
poorer occupational attainment
- drug use is associated with greater occupational income in early adulthood > by older ages drug use is associated with reduced occupational income
- possibly due to earlier exit from education like university in order to take occupations with greater earning capacity initially, but reduced long-term growth.
- drug use is associated with poorer occupational performance
- may be explained by poorer performance going undetected in younger adults in jobs with reduced growth capacity.
- important to clarify whether drug use causes reduced adult occupational attainment, or vice versa, or whether both are causes by a third variable such as psychiatric illness.
- greater cannabis and alcohol use in adolescence predicted reduced occupational performance in adulthood.
- when estimates of third variables were removed, the association between drug use and occupational performance remained significant.
- consistent with a causal relationship between adolescent drug use and reduced adult occupational attainment.
- poorer long-term economic prospects may be considered as a harm produced by drug use