That being said, the use of drug treatments in children is fraught with uncertainties. A number of conditions that may have similar names in adults and children do not appear to be the same condition. For example, what are often termed psychotic or schizophrenic disorders in children may in fact be pervasive developmental disorders rather than prodromes of an adult psychosis. While full-blown and severe bipolar disorder can occur in adolescence, this in fact is rare, and the use of treatments for bipolar disorders in adolescents should be correspondingly rare and should not happen in children. Children get depressed but, until recently, there was a clear recognition that these depressions are better regarded as distress rather than early-onset depressions of the type that happen to adults, and the resort to antidepressants should be much more cautious as a consequence.

Vigorous company marketing in recent years has added to the complexities in this area. When a drug company gets a licence to market a drug for attention deficit/hyperactivity disorder (ADHD), depression or bipolar disorder, this does not mark the point at which clinicians become able to use these drugs for children but rather the point at which the companies are enabled to start converting aspects of childhood into disorders and to build pressure to have these disorders treated with drugs. This marketing underpins the current mania for diagnosing bipolar disorders. In the case of many children with difficulties, what this means is that, if a diagnosis of ADHD and a prescription for stimulants fails, the child is likely to be rediagnosed as bipolar and put on a prescription for sedatives such as olanzapine or valproate.

Where once we were concerned that drugs such as cannabis might be gateway drugs leading onto harder drugs, now we have gateway diagnoses like ADHD or depression in children, or depression in adults, where failure of treatment does not lead on to rethinking the problem but rather to a move to a harder diagnosis such as bipolar disorder and a corresponding treatment. Clinical problems such as suicidality on selective serotonin-reuptake inhibitors (SSRIs) have become marketing opportunities for companies pushing compounds that are even more problematic in paediatric settings.

In recent years this mix of competing interests has been disturbed by the regulators, who since 1990 have been requesting companies to undertake trials in children to establish drug safety profiles. This has led to an extensive series of clinical trials, most of which have either not been reported or when reported have been couched in grossly misleading terms, so that while on the one hand we seem to be moving into an era where there are apparently more data that might inform clinical judgement, in fact there is a greater need than ever to be concerned about the quality of those data.

Another new development has seen companies faced with difficulties in proving that their drugs work, rather than informing clinicians or seeking a licence that would make at least part of their data public, producing grossly misleading articles and having academic staff make presentations at medical meetings on the reality of childhood illness and the benefits of the company’s medication. An added benefit of this approach, from a company perspective, in addition to keeping the data concealed, is that lecture fees for professors come to a lot less than paying the salaries and pension costs of sales staff.

The changing picture does not stem solely from company marketing. Other factors have helped to transform the picture. First, getting a diagnosis for a child, whether of autism, ADHD or another condition, has become a means in some cases to get the child other social supports, and in some cases disability payments. ³ Second, there is a general perception from the adult field that clinical trials have proved that the treatments work, and if they work and as a result reduce the risks for children that stem from an untreated condition, many parents will feel compelled to accept treatment. Third, there is a perception that the drugs do not have side effects, and clinicians do little to deter this perception. Fourth, in some instances parents do want to sedate their child and this need has meant that there has always been some use of psychotropic drugs for children. Fifth, there is a profoundly disturbing use of antipsychotics in particular among children in foster care and with learning disabilities that has been happening for a long time but has escalated in recent years. ⁴

A further important factor is the use of operational criteria. In 1980, the third edition of the Diagnostic and Statistical Manual (DSM III) introduced the notion of operational criteria to overcome the profound divides between biological psychiatry and psychodynamic approaches. We might not agree on the cause of a problem, or even its correct treatment, but we could surely agree whether five clinical features were present or not, and in the case of depression the presence of five out of nine agreed features means you ‘meet the criteria’ for the disorder. ⁵ Meeting criteria for a disorder is not the same thing as having it, though. For instance, pregnant women, or any of us who have influenza, would often meet the criteria for depression – if we lose sleep, have altered appetite, feel more anxious than usual, are more fatigued than usual and lose interest in things. In 1980 it was assumed that some sort of clinical judgement would be made, so that if there was another explanation for why a person had particular symptoms they would not be diagnosed as depressed. But once criteria began to be put up on the Internet, often by drug companies, many people doing their own research have found them and find that they meet the criteria, and have come to the conclusion that they or their children have some condition that they do not in fact have. I have had people with successful careers in public life who have accessed the Internet in this way tell me they have Asperger’s syndrome and ADHD, or possibly bipolar disorder. This is just simply wrong.

Finally, in the case of ADHD, we are witnessing something of a reverse phenomenon where pharmaceutical companies, buoyed by the growth of a paediatric market for stimulants, have supported campaigns to increase the recognition of adult forms of ADHD, and this has led to an increasing growth in the use of stimulants in adults.

Stimulants such as arsenic, strychnine, camphor and coca (later cocaine) have been used for over a century in the treatment of nervous problems. In a famous natural experiment, a flood in Pavlov’s laboratory in Leningrad in 1924, which nearly drowned his experimental dogs, left many of them nervous. Even though the shock in each case was the same, the reactions of the dogs was quite different, with some becoming severely disabled with what Pavlov called a traumatic neurosis and others less so. Also different was the response of those who were traumatised to treatments: some were helped by sedatives and others by stimulants. This raises the possibility that quite different drugs could be effective for the same condition, depending on the constitutional type (the personality) of the individual. ⁵

These ideas were later elaborated into a sophisticated theory of personality by Hans Eysenck, who, taking a concept first outlined by Carl Gustav Jung, distinguished between introverts and extraverts. According to both Jung and Eysenck, introverts handle their fears internally and in so doing predispose themselves to phobic and obsessional disorders, as well as neurotic anxiety. Extraverts handle their difficulties in the interpersonal space, so that the difficulties become problems both for themselves and others. In so doing they predispose themselves to hysteria and psychopathy. These dimensions of introversion and extraversion were, for Eysenck, biological realities; they were shaped by our genes rather than our upbringing. In support of this he pointed to a differential sensitivity between introverts and extraverts to the effects of stimulants and sedatives. Answers on the Eysenck Personality Questionnaire can, in fact, predict how much anaesthetic will be needed to put someone to sleep for surgery: introverts need much more than extraverts. Similarly, extraverts are much more sensitive to the effects of stimulants, which can have apparently paradoxical effects on them. ⁶

While these ideas took shape, the amphetamine series of molecules was first made in the decades preceding the First World War. ⁷ It took some years for chemists to appreciate their stimulant properties. Exploring these further led to the discovery of dexamphetamine (Dexedrine) in 1935, an amphetamine with much more marked stimulant properties than other amphetamines. This quickly swept away the use of other stimulants. Dexamphetamine was tried out in a range of conditions and found to be helpful. These included narcolepsy, anxiety disorders and a condition that has since come to be called ADHD.

In 1937, Charles Bradley reported on the beneficial effects of Benzedrine on a series of disturbed children in care in the following terms: ‘To see a single dose of Benzedrine produce a greater improvement in school performance than the combined efforts of a capable staff working in a most favourable setting, would have been all but demoralising to the teachers had not the improvement been so gratifying from a practical viewpoint.’⁸

The response of children to stimulants has now legitimised the concept of ADHD but in truth little is known about this condition. Among the range of difficult and disturbed children in institutional care in the 1930s, it was only a small group whom Bradley reported as responding to stimulants – others were given and responded to sedatives. But this response to stimulants led to a slow increase in the usage of the drugs. In 1954, another stimulant appeared: methylphenidate (Ritalin), which in clinical trials for the same group of children Bradley had looked at was also found to be effective. This helped trigger the emergence in the late 1950s of the concept of minimal brain dysfunction (MBD) to explain what appeared to many to be a paradoxical response – overactive children becoming calmer on a drug which agitated many adults. There was considerable speculation about the origins of MBD, with proposals ranging from minor birth injury through to allergic responses to food additives. Children with MBD were often said to have hyperactivity.

MBD in turn became ADHD in the third edition of the Diagnostic and Statistical Manual for Mental Disorders in 1980.9 ^{and 10} But this name, rather than indicating a well-understood disorder, simply describes a state in which some children may be overactive and others may be inattentive. Given the fluid nature of both inattentiveness and overactivity there is an inevitable risk that diagnoses will be made when they should not be. With the creation of ADHD a wide variety of disorders featuring overactivity and others with possible suggestions of minimal brain dysfunction merged and Ritalin, which had been available for 25 years before that, exploded into popular consciousness. ¹¹

Initially, these results from America were discounted in Europe. In America, the first explanations were in terms of something clearly being wrong with the brains of hyperactive children, so that drugs that abolished appetite, interfered with sleep and stimulated normal children produced the opposite effects in these ‘hyperactive’ children. Then Judy Rapoport demonstrated that similar effects could be shown in normal children, which introduced the notion that there was a paediatric response to these drugs that differed from the responses of adults. This idea has also since been discarded, leaving us with the options of either ADHD on one side, a brain disorder corrected by psychostimulants, or something akin to extraversion on the other side, a constitutional predisposition that many people have that makes them more sensitive to the calming effects of stimulants than introverts are. There is a third option outlined by Trevor Robbins, developed further below, which is that the effects of psychostimulants depend in part on the baseline activity rates of the person or animal taking them, leading to slowing down effects against a background of high activity rates and a stimulant effect against a background of low activity rates.

There are a number of extraordinary features of the current scene. One is that a taboo has been breached: the taboo of giving psychotropic drugs to children. Children, especially in North America, are being given cocktails of psychotropic drugs on a vast scale. A second point is the lack of pharmacological distinction between the drugs being used – Ritalin and Dexedrine – and a number of banned or controlled agents such as cocaine and speed. On the one hand, we can look at a group of drugs and see them as harmless, but a moment later we can see the same type of drug as a major threat to society.^{12 and 13}

While the response of overactive children to stimulants was once seen as paradoxical, and this for some pointed strongly to the pathological basis of the condition, it is now clear that many adults respond in just the same way, and equally that not all children respond this way. These elements of the picture suggest that what may be involved in the case of overactivity is a dimensional disorder related to extraversion rather than a categorical illness entity like ADHD, which companies are now suggesting affects both children and adults. When up to 15% of children in some areas are diagnosed with ADHD it becomes very difficult to believe they all have a clear-cut disease. ¹⁴

Whatever the reality, where once it was thought that treatment was time-limited and that children grew out of their difficulties, which most children in fact do, there has been a trend to recognising milder forms of the condition and difficulties in adults that might respond to stimulants. It is increasingly common to hear of college students, for instance, seeking scripts for stimulants around times of examinations and attributing their ability to master the concentration problems that come with large paper loads to treatment of their illness, where in fact this is simply a quite normal response to stimulants – which comes with a very predictable set of attendant problems, one of which is that they get a diagnosis (see Ch. 18).

Beyond this a number of clinicians in recent years, in books like Shadow Syndromes, have very actively promoted the idea of adult ADHD and the use of stimulants for such people. Some people will unquestionably find a benefit from this but benefits do not make a diagnosis and there are other ways to interpret what is happening, as outlined above and further below.