Psychopharmacology: Substance Misuse Disorders

C. Harmful use

Harmful use (C) arises when substance misuse is continued over a long
period (at least 1 month) by a patient, despite damage to the user’s
physical or mental health. The patient’s occupation and family are often
severely affected, with the damage being played down by the patient.
There is insufficient information to diagnose dependence syndrome (B).
Acute intoxication (A) occurs due to the immediate effect of consumption
of a specific substance and the direct effects which result. Withdrawal
state (D) is the physical dependence on a drug and the associated features
which occur during abstinence. Severe withdrawal can be complicated by
delirium, for example, delirium tremens in alcohol withdrawal. Psychotic
disorder (E) as a result of alcohol use is usually characterized by auditory
hallucinations and sometimes paranoid thinking.

A. Withdrawal state

When a patient is dependent on a drug, a period of abstinence may
lead to withdrawal symptoms (A). Features are specific to individual
drugs and can include both physical symptoms (e.g. appetite change and
fatigue) and/or psychological symptoms (e.g. anxiety and depression).
Withdrawal symptoms are relieved by reinstatement (starting drinking
again). Complicated withdrawal (B) occurs when the withdrawal state
is associated with delirium, seizures or psychotic features. Amnestic
syndrome (C) is associated with chronic loss of memory. There is often
difficulty learning new material as well as time perception. Residual
disorder (D) occurs when symptoms of withdrawal persist despite
continued abstinence. Depression (E) would have a history of at least 2
weeks.

A. Wernicke’s encephalopathy

Wernicke’s encephalopathy (A) is seen in patients with alcohol dependence
and is caused by thiamine (vitamin B1) deficiency. It is characterized
by the triad of ataxia, confusion and ophthalmoplegia (most often
involving the lateral rectus). Alcohol withdrawal (B) occurs in the acute
setting, a day or two after the person last had a drink. Symptoms can be
divided into physical (coarse tremor, sweating, insomnia, vomiting and
tachycardia) and psychiatric (visual, tactile or auditory hallucinations
or illusions. Korsakoff’s syndrome (C) is a later complication following
Wernicke’s encephalopathy and is characterized by amnesia with a
normal level of consciousness.

B. Alcohol intoxication

The symptoms experienced as a result of alcohol intoxication (B) is
dependent on the blood alcohol concentration (BAC). At a low BAC alcohol
causes elevated mood and disinhibition, with an increased BAC leading
to slurred speech, ataxia, aggressiveness and eventually unconsciousness.
Alcohol-induced amnesia (A), also known as alcoholic palimpsest, typically
involves short-term anterograde memory loss with the patient unable to
recall events during a specific time window. Harmful drinking (C) occurs
when a patient continues to drink despite continued damage to their
mental and/or physical health. At-risk drinking (D) is the stage when the
user is at increased health risk due to situational factors, e.g. pregnancy
or drink driving. Alcohol dependence (E) is characterized by increased
tolerance and withdrawal features on abstinence, amongst other features.

C. Othello syndrome

Othello syndrome (C), also known as pathological or morbid jealousy, is a
disorder which can occur as a result of either current or previous alcohol
abuse although it occurs in other psychiatric disorders. The patient holds
delusional beliefs that his/her partner is being unfaithful and may adopt
extreme methods to prove this, e.g. hiring private detectives or planting
secret cameras. The syndrome is associated with an increased risk of
homicide towards the partner. Alcoholic hallucinosis (A) is characterized
by auditory hallucinations. Alcohol-induced psychotic disorder (B) may
occur as a result of long-term alcohol misuse. It differs from Othello
syndrome as classically delusions are grandiose or persecutory. Alcoholic
dementia (D) results in widespread cognitive difficulties due to the toxic
effect of alcohol. Korsakoff’s syndrome (E) is an amnestic syndrome
which results in severe anterograde amnesia.

D. Central pontine myelinolysis

Central pontine myelinolysis (D) occurs due to severe damage to the myelin
sheath of neurons in the pons. The most common cause in alcoholics is
over-rapid correction of hyponatraemia. Symptoms include a pseudobulbar
palsy and quadriplegia. Wernicke–Korsakoff syndrome (A) is characterized
by neuronal degeneration in the mammillary bodies secondary to
thiamine deficiency in heavy drinkers. Wernicke’s encephalopathy is
defined by the classic triad of confusion, ophthalmoplegia and ataxia.
Korsakoff’s syndrome is characterized by chronic anterograde amnesia.

B. Tuberculosis

Long-term alcohol abuse can lead to suppression of the immune system,
putting users at risk of Mycobacterium tuberculosis infection (B). Characteristic
features include low grade fever, night sweats, weight loss and haemoptysis.
Dilated cardiomyopathy (A) is associated with alcohol dependence and
the patient will present with symptoms such as breathlessness, pulmonary
oedema and/or arrhythmia. Atrial fibrillation (C) can be caused by excessive
alcohol consumption or ‘binge drinking’. Alcohol abusers are at increased risk
of pneumonia (D) for the same reasons as TB: a suppressed immune system.
The most common pathogens responsible are Klebsiella and Streptococcus
pneumoniae. Symptoms will include high fever, purulent cough, pleuritic
chest pain and shortness of breath. Stroke (E) is very unlikely at this age.

C. Barrett’s oesophagus

Barrett’s oesophagus (C) arises from long-term distal oesophageal exposure
to alcohol which causes squamous epithelium to undergo metaplasia,
resulting in the formation of columnar epithelium. It is diagnosed on
endoscopy after the patient complains of long-standing heartburn. There
is a risk that the Barrett’s oesophagus may progress to adenocarcinoma.
Alcoholic liver disease (A) exists as a spectrum of liver pathology: it begins
with fatty change and progresses to alcoholic hepatitis in heavy drinkers.
Cirrhosis may arise in alcoholics after 10–30 years of persistent use.
Acute gastritis (B) is defined as the inflammation of the stomach mucosa
and is caused by excessive alcohol consumption. Epigastric pain, nausea,
vomiting and loss of appetite are characteristic features. Mallory–Weiss
tears (D) arise as a result of an alcoholic binge which triggers a vomiting
episode. Continued vomiting can cause an oesophageal tear associated
with haematemesis. Alcohol is the most common cause of chronic
pancreatitis (E). Chronic pancreatitis is characterized by epigastric pain
which radiates to the back (relieved on sitting forward), steatorrhoea (fatty
stools) and diabetes.

A. Social phobia

Alcohol has anxiolytic properties and, as a result, patients with anxiety
syndromes such as social phobia (A) may self-medicate to relieve the
symptoms. Furthermore, dependent patients who undergo alcohol
withdrawal may experience anxiety and panic symptoms. Alcohol is a
depressant and when combined with social consequences of excessive use,
can result in depression (B). Long-term alcohol use can cause a psychotic
disorder (C) to develop, characterized by hallucinations and delusions.
Hallucinations are usually auditory but may be visual. Delusions are
primarily grandiose or persecutory in nature. Symptoms are transient
and resolve with abstinence of alcohol. Generalized anxiety disorder (D)
tends to have less focused and situationally dependent symptoms. Morbid
jealousy (E) is associated with alcohol dependency and will manifest as a
delusion that a partner is unfaithful. There may be associated impotence
as well as a high risk of violence towards the partner.

B. Cocaine

Acute psychological effects of cocaine (B) are increased alertness,
euphoria, irritability, delusions and hallucinations. Cocaine users may
also experience the sensation of insects crawling on their skin, known as
formication. Physical effects of cocaine are tachycardia, hypertension and
arrhythmias. Heroin (A) induces initial euphoria followed by sedation.
Physical signs will include pin-point pupils, bradycardia, respiratory
depression and constipation. There are few psychiatric sequelae associated
with its use. Characteristics of LSD (lysergic acid diethylamide) (C)
intoxication include depersonalization, illusions, synaesthesia and
visual hallucinations. Caffeine intoxication (D) can lead to headache,
anxiety, confusion, tremors, irregular heart beat, nausea and vomiting.
Benzodiazepines (E) are central nervous system depressants and may lead
to drowsiness, confusion and reduced anxiety

E. Cannabis

Long-term cannabis use (E) has been linked to increasing the risk of
schizophrenia. Patients with the Val-Val polymorphism of the gene coding
for catechol-O-methyl transferase are highly susceptible to developing
schizophrenia after chronic cannabis use. Chronic barbiturate users (A)
may show signs of increased irritability and aggressiveness as well as
fatigue. Magic mushrooms (B) contain active chemicals such as psilocybin
and psilocin which cause visual disturbances. Chronic glue sniffing (C) can
lead to irreversible brain damage, memory defects and mood disorders.
Heroin (D) rarely causes psychiatric symptoms.

A. Education and advice

A 750mL bottle of 12 per cent wine is around nine units; therefore this
patient is drinking 36 units of alcohol per week. This level of drinking
may be associated with a small increased risk of harm. Men are advised
not to drink more than 21 units per week and four units per day. Early
interventional advice within the GP setting can lead to a reduction
in alcohol consumption and reduce the risk of progression to heavier
drinking. Alcoholics Anonymous (B) offers long-term support for people
with alcohol dependence. Disulfiram and acamprosate are both used in
maintenance of abstinence in people who have been alcohol dependent.
Antipsychotics (E) have no place in the management of this scenario.

A. Oral chlordiazepoxide

The patient is suffering from delirium tremens due to alcohol withdrawal.
Delirium tremens usually presents 24 hours to 1 week after drinking
cessation and patients may experience marked confusion, visual and
auditory hallucinations with autonomic instability (sweating, a raised
pulse and blood pressure). Oral chlordiazepoxide (A) is the most
appropriate drug to use in this situation. It reduces the severity of
symptoms and reduces the risk of seizures. IV chlordiazepoxide (D) or
diazepam (E) would only be used if the oral route was unavailable. Any
person presenting with alcohol withdrawal should also receive high dose
intravenous thiamine, not oral thiamine (C) which is poorly absorbed.
Antipsychotics (B) should be used only if psychotic symptoms are
persistent.