Diagnosing schizophrenia according to ICD-11 -- code 6A20

What schizophrenia is from the ICD-11 perspective

In the eleventh revision of the International Classification of Diseases (ICD-11), developed by the World Health Organization, schizophrenia has the code 6A20 and belongs to the group of disorders described as schizophrenia or other primary psychotic disorders. The word primary means here that the symptoms are not a direct effect of another illness or of the action of substances, but constitute the core of a self-standing disorder.

The essence of schizophrenia is persistent psychotic symptoms, that is, symptoms associated with a loss of contact with reality. These include, among others, delusions -- lasting false beliefs resistant to argument; hallucinations -- perceptions without a real stimulus, for example hearing voices; and disorganisation of thinking and speech, which makes it difficult for others to understand what is being said.

The picture of schizophrenia is not, however, limited to these symptoms. They are often accompanied by negative symptoms, such as flattening of emotions, social withdrawal, and weakened motivation, as well as difficulties in the area of cognitive functions, for example attention and memory. Contact with other people and everyday activities become markedly limited, and the ability to function independently may be seriously impaired.

It is worth dispelling a common misunderstanding from the outset. Schizophrenia does not mean a split personality or alternating between being a different person -- that is an image established in popular culture, but a mistaken one. This text serves education and a better understanding of the disorder, but it does not replace clinical assessment. A diagnosis of schizophrenia is made solely by a qualified specialist after a full examination.

Positive symptoms -- delusions and hallucinations

Positive symptoms, also called productive symptoms, are phenomena that, in the mind of the ill person, are present in addition, over and above ordinary experience. The word positive does not denote anything good here -- it indicates only that something is appearing, in contrast to negative symptoms, where something is being lost. The most important positive symptoms are delusions and hallucinations.

Delusions are lasting, false beliefs held despite evidence to the contrary and not amenable to correction by argument. They can take various forms. Persecutory delusions are common, in which the person is convinced they are being followed or that someone wants to harm them, as are referential delusions, when ordinary events are perceived as directed straight at them. Grandiose delusions and other kinds also occur.

Hallucinations, also called perceptual disturbances arising without a real external stimulus, are most often auditory in schizophrenia -- hearing voices that are not present to those around. Of particular diagnostic significance are voices commenting on the patient's behaviour or discussing them among themselves. Hallucinations may also concern other senses.

Positive symptoms also include particular disturbances of thinking, such as the sense that thoughts are being inserted, withdrawn, broadcast, or experienced as belonging to someone else, as well as disorganisation of thinking and speech, through which utterances become difficult to understand. These symptoms can be a source of great fear and distress for the ill person.

Negative and cognitive symptoms

Negative symptoms consist of a loss or weakening of functions that are present in health. They can be less noticeable than delusions or hallucinations, but they have a major impact on functioning and often persist longer. They are also easily misperceived as laziness, reluctance, or a lack of engagement, even though they are a manifestation of the disorder.

Typical negative symptoms include flattening of affect, that is, a weakening of the expression of emotions visible in impoverished facial expression, poor modulation of the voice, and limited eye contact. There is also avolition, that is, a weakening of will and motivation that makes it difficult to start and complete everyday activities, as well as anhedonia, that is, a reduced ability to feel pleasure.

Social withdrawal is characteristic -- a reduction of contacts and of interest in relationships -- as is alogia, that is, an impoverishment of speech and of the content of utterances. Negative symptoms together make up the picture of a person increasingly less active, less emotionally present, and gradually withdrawing from their previous life.

A separate area is cognitive symptoms, that is, difficulties in attention, memory, the speed of information processing, and planning. Although they are not as visible as the positive symptoms, they significantly hinder learning, work, and independent functioning. ICD-11 emphasises the dimensional character of these symptoms, which makes it possible to describe separately the intensity of the individual symptom groups in a given patient.

Diagnostic requirements for schizophrenia according to ICD-11

ICD-11 describes schizophrenia using diagnostic requirements, rather than a rigid list of points to be ticked off mechanically. The basic condition is the presence of psychotic symptoms. It is required, moreover, that the picture include at least one of the symptoms regarded as core to the disorder, such as delusions, hallucinations, disorganisation of thinking, or experiences of being acted upon and of influence on thoughts.

The second condition is the time threshold. The symptoms must persist for most of the time over a period of at least one month. This requirement has an important differentiating sense -- it distinguishes schizophrenia from shorter psychotic states. If the symptoms resolve earlier, the diagnosis is steered towards other entities, for example towards acute and transient psychotic disorder.

The third condition is a significant impairment of functioning. The symptoms must genuinely affect everyday life -- relationships, work or study, and independent coping. Schizophrenia is a disorder that, during the symptomatic period, usually clearly disrupts functioning, although its intensity varies and periods of remission are possible.

The fourth condition is the exclusion of other causes. The symptoms must not be explained by the action of psychoactive substances or medication, by a neurological illness, or by another somatic health condition. Only the fulfilment of all these requirements together -- the presence of core symptoms, a sufficient duration, an impact on functioning, and the exclusion of other causes -- makes it possible to consider a diagnosis of schizophrenia.

The time threshold and its significance

The requirement that symptoms persist for at least one month is not a formality, but a deliberate element of the definition. Short-lived psychotic states may have a different course, a different prognosis, and different needs than schizophrenia, which is why the classification separates them by means of a time criterion.

If psychotic symptoms appear suddenly and resolve within a few days or a few weeks, the picture corresponds rather to acute and transient psychotic disorder (code 6A23), which by definition has a short course. Only the persistence of symptoms over a longer period steers the diagnosis towards schizophrenia.

The time threshold also means that a diagnosis of schizophrenia should not be made hastily, on the basis of symptoms present for a few days. A premature diagnosis is one of the errors against which the classification protects. In clinical practice, a period of observation is sometimes needed in order to assess whether the symptoms are of a lasting character.

The classification, at the same time, permits clinical judgement. ICD-11 does not treat the time threshold as an absolute, mechanical boundary, but as an important indication. The specialist takes into account the whole picture, including the intensity of the symptoms, their development over time, and history data about the patient's earlier functioning.

The course of schizophrenia and its specification

Schizophrenia does not have a single, fixed course. In some people, symptoms occur in distinct episodes with periods of improvement between them; in others, they persist in a more continuous manner. ICD-11 makes it possible to reflect these differences, refining the diagnosis by means of specifiers of the course and the current state.

The classification distinguishes, among others, schizophrenia, first episode -- when symptoms meet the criteria for diagnosis for the first time in life; schizophrenia, multiple episodes, when after an earlier episode a further relapse has occurred; and schizophrenia, continuous, when symptoms persist in a continuous manner without distinct periods of remission.

The current clinical state is specified separately. This may be a symptomatic state, partial remission, when the symptoms have clearly diminished but have not resolved entirely, or full remission, when symptoms are currently not present. Such refinement makes it possible to track changes over time and to better describe the situation of the individual patient.

The possibility of specifying the course and state shows that a diagnosis of schizophrenia is not an unchanging verdict. The picture may change, and periods of remission are part of the course of many disorders in this group. The diagnosis describes the current state and its history, not a closed diagnosis fixed once and for all.

The dimensional approach in describing psychotic symptoms

One of the important changes in ICD-11 is the strengthening of the dimensional approach in psychotic disorders. The dimensional approach describes a disorder not only as a category to which the patient does or does not belong, but also by means of the intensity of the individual symptom groups, rated on a scale.

In practice, this means that alongside a diagnosis of schizophrenia it is possible to describe separately the intensity of different symptom dimensions -- for example positive symptoms, such as delusions and hallucinations; negative symptoms, such as withdrawal and flattening of emotions; symptoms of disorganisation; as well as mood symptoms and cognitive symptoms.

The sense of this change is practical. Two people with the same diagnosis of schizophrenia may differ greatly in their picture. In one, intense delusions and hallucinations predominate; in the other, negative and cognitive symptoms come to the fore. The dimensional description captures these differences more faithfully than the diagnostic label alone.

The dimensional approach also translates better into planning help tailored to the individual patient, rather than to an averaged category. This is an example of the general direction in which ICD-11 diagnostics is heading -- from rigid divisions towards a fuller, more individualised description of the clinical picture.

Differential diagnosis of schizophrenia

Psychotic symptoms are not specific to schizophrenia alone, which is why an inseparable element of the diagnosis is differential diagnosis, that is, considering and ruling out other disorders that could explain the same picture. The group of schizophrenia and other primary psychotic disorders includes several entities that can be difficult to distinguish.

Schizoaffective disorder (code 6A21) is diagnosed when symptoms of schizophrenia and a distinct mood episode -- depressive or manic -- occur simultaneously and with comparable intensity within the same episode. Delusional disorder (code 6A24), in turn, is characterised by persistent delusions in the absence of other intense symptoms typical of schizophrenia.

The aforementioned acute and transient psychotic disorder (code 6A23) is distinguished from schizophrenia by its short course and the rapid resolution of symptoms. A separate entity is schizotypal disorder (code 6A22), describing an established pattern of eccentricity, atypical beliefs, and difficulties in relationships, which does not reach the intensity of a full-blown psychosis.

Differential diagnosis also includes disorders from outside this group. Psychotic symptoms may occur in the course of mood disorders, for example in bipolar type I disorder (code 6A60) with psychotic symptoms. It is also necessary to rule out the influence of substances, including alcohol (disorders due to alcohol use have code 6C40), as well as neurological illnesses and other somatic conditions.

What schizophrenia does not mean -- debunking myths

Many harmful misconceptions have grown up around schizophrenia, which hinder understanding of the disorder and intensify stigmatisation. The most common is confusing schizophrenia with a split personality. These are two completely different phenomena. Schizophrenia concerns above all a loss of contact with reality, not alternating between being a different person.

A second widespread myth links schizophrenia with aggression and danger. This is an image heavily distorted by popular culture and media coverage. Most people with this disorder do not pose a threat to those around them, and in situations of crisis they themselves more often need support and protection. Equating the disorder with violence is unjust and harmful.

Another myth holds that schizophrenia means an inevitable, progressive decline and a lack of prospects. In fact, the course of the disorder is varied. Periods of partial and full remission are possible, and many people, with appropriate support, function, maintain relationships, and pursue goals that are important to them. The diagnosis is not a verdict.

Debunking these myths has practical significance. Stigmatisation causes people experiencing psychotic symptoms to delay seeking help, and those around them to react with fear instead of support. Sound, ICD-11-based knowledge of what schizophrenia is and what it is not makes early contact with a specialist easier.

What the process of diagnosis looks like and when to seek help

A diagnosis of schizophrenia is made by a qualified specialist, most often a psychiatrist, on the basis of a full clinical assessment. This encompasses a detailed history concerning the symptoms, their onset, duration, and impact on functioning, observation, and often also information from loved ones and earlier documentation.

An important element is ruling out other causes of the symptoms. The specialist takes into account the possible influence of substances and medication, as well as neurological illnesses and other somatic conditions, which is why the assessment may also include investigations directed at these causes. Only the whole of this assessment, combined with differential diagnosis against other psychotic disorders, makes it possible to regard the diagnosis as justified.

Psychotic symptoms -- such as intense, inexplicable suspiciousness, hearing voices, beliefs clearly detached from reality, or escalating withdrawal and disorganisation -- require urgent consultation with a specialist. Early contact is important, because it makes it possible to provide the person with appropriate support sooner.

In a situation of immediate threat to life or health -- one's own or another person's -- urgent help must be sought without delay. ICD-11 diagnostics provides an ordered language for describing the disorder, but responsibility for the diagnosis and further management always rests with a qualified specialist, not with a self-assessment of symptoms.

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