The presence of withdrawal symptoms that manifest psychologically makes it easy to mistake these symptoms for relapse of an underlying condition by both patients and clinicians. 6, 7, 8 Patients commonly report that their withdrawal symptoms are mis-diagnosed as relapse of the condition for which their drug was originally prescribed, or as a new-onset mental health disorder. 6, 7, 8 Such mis-diagnosis is understandable, given the limited awareness of withdrawal symptoms from psychiatric drugs, including their severity and duration and because they have often been downplayed as 'discontinuation' symptoms, or characterised as 'mild and brief' based on short-term industry trials. 9 The waters have also been muddied by commentators claiming that some psychiatric drugs can not cause withdrawal effects because they are not addictive 10, 11 - whereas adaptation to a drug over time (often called 'physical dependence') is all that is required for withdrawal symptoms to emerge when reducing or stopping the drug, without the need for addiction (which involves psychological dependence as well, characterised by craving, compulsion, etc). 12, 13
On the other hand, physicians are well practised at detecting relapse: when patients present with mood or anxiety symptoms, other psychiatric symptoms or disordered behaviour, especially when such symptoms are severe and long lasting, relapse is often higher on a list of differentials than withdrawal. 6, 8 However, over the past few years there has been increasing recognition that withdrawal effects from psychiatric drugs can cause severe symptoms, which can themselves be long-lasting and in some instances appear similar to the presentation of other mental health conditions.
The term 'dependence' has come to be used interchangeably with 'addiction' (to mean uncontrolled drug-seeking behaviour). 12 Inevitably this has led to some unfortunate confusion. 12 This choice of language was made in DSM-III-R because the term 'addiction' was thought to be pejorative whilst the word 'dependence' was thought more neutral. 12 However, the original usage of the word 'dependence' referred to 'physiological adaptation that occurs when medications acting on the central nervous system are ingested with rebound when the medication is abruptly discontinued'. 12 The National Institute on Drug Abuse (NIDA) in the USA states 'Dependence means that when a person stops using a drug, their body goes through “withdrawal”: a group of physical and mental symptoms that can range from mild (if the drug is caffeine) to life-threatening … Many people who take a prescription medicine every day over a long period of time can become dependent; when they go off the drug, they need to do it gradually, to avoid withdrawal discomfort. But people who are dependent on a drug or medicine aren't necessarily addicted.' 13 In addition, Goodman and Gilman's textbook of pharmacology points out 'The appearance of a withdrawal syndrome when administration of the drug is terminated is the only actual evidence of physical dependence.' 14
All major classes of psychiatric drugs can be associated with withdrawal symptoms on cessation or dose reduction. These symptoms occur in a substantial proportion of patients, as a result of physical dependence (a normal neurobiological response to drugs that act on the central nervous system). 2, 12, 15, 16, 17, 18 Physical dependence to psychiatric drugs arises because the body and brain undergo adaptations to the presence of a drug, countering its effect in order to maintain homeostasis. 12, 19, 20 It is also clear that many psychiatric drugs - with the exception of benzodiazepines, stimulants and some antidepressants such as tranylcypromine and amineptine - do not cause addiction, as they do not induce compulsion, craving and other symptoms of addiction. 11, 21 Sometimes mis-understanding that withdrawal symptoms arise merely from adaptation to psychiatric drugs after chronic use leads to misplaced accusations of addiction, misuse or abuse when patients report withdrawal symptoms on trying to stop.
Some patients may be less interested in academic distinctions between dependence and addiction and more interested in the reality that they cannot stop their psychiatric drugs because of unpleasant withdrawal effects. They may therefore describe them colloquially as 'addictive', 22, 23 though most psychiatric drugs do not fit the strict definition of this property. Some patients may also not be happy being described as 'dependent' on psychiatric drugs (which they may still associate with the concept of addiction), and in this case, it may be better to talk in terms of 'neuroadaptation' or 'adaptation'.
The term 'discontinuation symptom' was promoted by drug manufacturers to minimise patient concerns regarding their product and to prevent an association with the idea of addiction. 9, 24 There is now widespread recognition that this euphemism is misleading and that its use minimises the potentially adverse consequences of stopping psychiatric drugs; withdrawal symptoms do not imply addiction. 9, 25, 26 The more pharmacologically accurate term is 'withdrawal symptoms', now adopted by Royal College of Psychiatrists, 9, 27 the British Medical Association 9 and NICE in the UK for antidepressants 28, 29 and by academics for antipsychotics, 1, 2, 30 mood stabilisers, 28 and long used with regards benzodiazepines, stimulants and gabapentinoids. 2