Substance use and misuse

‘Humankind cannot bear very much reality’ T.S. Eliot

‘The urge to escape, the longing to transcend themselves, if only for a few minutes, is and always has been one of the principal appetites of the soul.’ Aldous Huxley

People in all cultures, at all times throughout history, have sought out mood or perception-altering substances. 25% of adults smoke; 90% drink alcohol; 33% have lifetime experience of one illegal drug (mostly canna- bis). Society’s attitude to substance use and to those with substance use problems has varied, from prohibition and condemnation to tolerance and treatment. Within British society at the moment caffeine use is legal and accepted; alcohol and tobacco use are accepted with legal limitations; and other substances have severe legal limitations—some available only on prescription, others not at all. Despite this, the harmful effects of alcohol dwarf those of other drugs.

Many of the abused substances subsequently described have been used in their naturally occurring form throughout history (e.g. the chewing of coca leaves by Peruvian Indians). There has been a tendency for the development of more potent drug preparations which contain a higher concentration of the active ingredient (e.g. freebase cocaine), and the development of routes of administration which produce more rapid and intense effects (e.g. IV use). This has generally been associated with an increase in the attendant problems.

Patients presenting with drug misuse problems represent only a small percentage of those who take drugs. Little is known about the non- presenting drug users. Their numbers may be hinted at by community surveys, but they are otherwise poorly studied. It is clear, however, that the normal route from use of to abstinence from a substance is the indi- vidual deciding to discontinue use and then doing so, without medicalconsultation or help.

Reasons given for substance use are varied, and may change over the course of a patient’s life. They include: a search for a ‘high’; a search for a repeat of initial pleasurable effects; cultural norm in some subcultures; self-medication for anxiety, social phobia, insomnia, symptoms of psychotic illness, and to prevent development of withdrawal symptoms. There is evi- dence for increased vulnerability to substance use in those with a family history of substance misuse, and the role of environmental stressors in perpetuating use cannot be underplayed.

The pattern of risks associated with substance use varies with the sub- stance taken, the dose and route of administration, and the setting. They include: acute toxicity; behavioural toxicity (e.g. jumping from height due to believing one can fly); toxic effects of drug contaminants; secondary medical problems; secondary psychiatric problems; risk of development of dependency; and negative social, occupational, marital, and forensic consequences.

Substance misuse disorders

Acute intoxication The pattern of reversible physical and mental abnormalities caused by the direct effects of the substance. These are specific and characteristic for each substance (e.g. disinhibition and ataxia for alcohol, euphoria and visual sensory distortions for LSD). Most substances have both pleasurable and unpleasant acute effects; for some, the balance of positive and negative effects is situation-, dose-, and route- dependent.

At-risk use A pattern of substance use where the person is at increased risk of harming their physical or mental health. This is not a discrete point but shades into both normal consumption and harmful use. At-risk use depends not only on absolute amounts taken but also on the situations and associated behaviours (e.g. any alcohol use is risky if associated with driving).

Harmful use The continuation of substance use despite evidence of damage to the user’s physical or mental health or to their social, occupational, and familial well-being. This damage may be denied or minimized by the individual concerned.

Dependence The layman’s ‘addiction’. Encompasses a range of features initially described in connection with alcohol abuse (b p. 542), now recognized as a syndrome associated with a range of substances. Dependence includes both physical dependence (the physical adaptations to chronic, regular use) and psychological dependence (the behavioural adaptations). In some drugs (e.g. hallucinogens), no physical dependence features are seen.

Withdrawal Where there is physical dependence on a drug, abstinence will generally lead to features of withdrawal. These are characteristic for each drug. Some drugs are not associated with any withdrawals; some with

mild symptoms only; and some with significant withdrawal syndromes. Clinically significant withdrawals are recognized in dependence on alcohol, opiates, nicotine, BDZs, amfetamines, and cocaine. Symptoms of

withdrawal are often the ‘opposite’ of the acute effects of the drug (e.g. agitation and insomnia on BDZ withdrawal).

Complicated withdrawal Withdrawals can be simple, or complicated by the development of seizures, delirium, or psychotic features.

Substance-induced psychotic disorder Illness characterized by hallucinations and/or delusions occurring as a direct result of substance- induced neurotoxicity. Psychotic features may occur during intoxication and withdrawal states, or develop on a background of harmful or dependent use. There may be diagnostic confusion between these patients and those with primary psychotic illness and comorbid substance misuse. Substance-induced illnesses will be associated in time with episodes of substance misuse, will occur more readily with specific substances (e.g. cocaine) and may have atypical clinical features (e.g. late first presentation with psychosis, prominence of non-auditory hallucinations).

Cognitive impairment syndromes Reversible cognitive deficits occur during intoxication. Persisting impairment (in some cases amounting to dementia) caused by chronic substance use is recognized for alcohol, volatile chemicals, BDZs, and, debatably, cannabis. Cognitive impairment is associated with heavy chronic harmful use/dependence and shows gradual deterioration with continued use and either a halt in the rate of decline, or gradual improvement with abstinence.

Residual disorders Several conditions exist (e.g. alcoholic hallucinosis, b p. 568; persisting drug-induced psychosis, b p. 604; LSD flashbacks, b p. 586) where there are continuing symptoms despite continuing abstinence from the drug.

Exacerbation of pre-existing disorder All other psychiatric illnesses, especially anxiety and panic disorders, mood disorders, and psychotic illnesses may be associated with comorbid substance use. Although this may result in exacerbation of the patient’s symptoms and a decline in treatment effectiveness, it can be understood as a desire to self- medicate (e.g. alcohol taken as a hypnotic in depressive illness) or escape unpleasant symptoms (e.g. opiates taken to ‘blot out’ derogatory auditory hallucinations). Sometimes there is debate about whether there is, for example, a primary mood disorder with secondary alcohol use or vice versa. Careful examination of the time course of the illness may reveal the answer. In any case, it is advisable to address substance misuse problems first, as this may produce secondary mood improvements and continuing substance misuse will limit antidepressant treatment effectiveness.

The dependence syndrome

This is a clinical syndrome describing the features of substance dependence. It was described initially by Edwards and Gross1 as a provisional description of alcohol dependence, but may be applied to the description of drug dependence. These features form the core of both ICD-10 and DSM-IV descriptions of substance dependence.

• Primacy of drug-seeking behaviour Also called ‘salience’ of drug use. The drug and the need to obtain it become the most important things in the person’s life, taking priority over all other activities and interests. Thus drug use becomes more important than retaining job or relationships, remaining financially solvent and in good physical health, and may diminish moral sense leading to criminal activity and fraud. This diminishes the ‘holds’ on a person’s continued use. If he rates drug use above health, then stern warnings about impending illness are likely to mean little.
• Narrowing of the drug-taking repertoire The user moves from a range of drugs to a single drug taken in preference to all others. The setting of drug use, the route of use, and the individuals with whom the drug is taken may also become stereotyped.
• Increased tolerance to the effects of the drug The user finds that more of the drug must be taken to achieve the same effects. They may also attempt to combat increasing tolerance by choosing a more rapidly acting route of administration (e.g. IV rather than smoked), or by choosing a more rapidly acting form (e.g. freebase cocaine rather than cocaine hydrochloride). In advanced dependence there may be a sudden loss of previous tolerance; the mechanism for this is unknown.

Clinically, tolerance is exhibited by individuals who are able to display no or few signs of intoxication while at a blood level in which intoxication would be evident in a non-dependent individual.

• Loss of control of consumption A subjective sense of inability to restrict further consumption once the drug is taken.
• Signs of withdrawal on attempted abstinence A withdrawal syndrome, characteristic for each drug, may develop. This may be only regularly experienced in the mornings because at all other times the blood level is kept above the required level.
• Drug taking to avoid development of withdrawal symptoms The user learns to anticipate and avoid withdrawals (e.g. having the drug available on waking).
• Continued drug use despite negative consequences The user persists in drug use even when threatened with significant losses as a direct consequence of continued use (e.g. marital break-up, prison term, loss of job).
• Rapid reinstatement of previous pattern of drug use after abstinence Characteristically, when the user relapses to drug use after a period of abstinence, they are at risk of a return to the dependent pattern in a much shorter period than the time initially taken to reach dependent use.

A model for understanding motivation and action towards change in harm- ful patterns of drug use was proposed by Prochaska and DiClemente.1 Motivation is regarded as a prerequisite for and a precursor to action towards abstinence or more controlled drug use. This model can be used when trying to tailor treatments to the individual.

• Pre-contemplation The user does not recognize that problem use exists, although this may be increasingly obvious to those around them.
• Contemplation The user may accept that there is a problem and begins to look at both the positive and negative aspects of continued drug use.
• Decision The point at which the user decides on whether to continue drug use or attempt change.
• Action The point of motivation, where the user attempts change. A variety of routes exist by which change may be attempted, which may or may not include medical services.
• Maintenance A stage of maintaining gains made and attempting to improve those areas of life harmed by drug use.
• Relapse A return to previous behaviour, but with the possibility of gaining useful strategies to extend the maintenance period on the user’s next attempt.

Harm reduction

Harm reduction is a method of managing drug users in which it is accepted that steps can be taken to reduce the mortality and morbidity for the user without necessarily insisting on abstinence from drugs. This approach gained currency during the 1980s in an attempt to halt the projected AIDS epidemic. The majority of patients will present before abstinence is a real- istic or achievable goal for them. Optimum care for this group of patients will involve engaging them with the service, exploring and encouraging motivation to change, and suggesting harm reduction strategies. Examples of such strategies include:

• Advice directed at use of safer drugs or routes of administration.
• Advice regarding safer injecting practice (b p. 583).
• Advice regarding safe sex.
• Prescription of maintenance opiates (substitution prescribing) or BDZs.
• Assessment and treatment of comorbid physical or mental illness.
• Engagement with other sources of help (e.g. social work, housing).

Drug misuse is a community problem. Some aspects of harm reduction include consideration of reduction of morbidity to the community more gen- erally. Prescription of methadone may reduce criminality in a dependent individual, with consequent community benefit. Equally, there is a responsibility with the prescriber to consider the potential for community harm via leakage and accidental overdose when monitoring the prescription of any drug.