The psychoses are often poorly understood by lay persons, with schizophrenia and 'split personality' being confused with one another. In fact, the symptoms experienced by schizophrenics are those we usually associate with madness: hearing voices, thinking that aliens are out to get them, or believing that they are the son of God. Schizophrenia often occurs during the late teens or early twenties, and affects no less than 1% of the population. This entry looks at the unusual symptoms that psychotic individuals experience, and also covers the causes, diagnosis, treatment and prognosis of schizophrenia.

Causes of Schizophrenia

There is no single known cause of schizophrenia. Studies have shown that there is a definite genetic element, with the risk of a schizophrenic's child developing the condition being around 13%. It is also known that schizophrenics tend to be born in late winter or spring, suggesting a link to viral infections before birth. Stressful life events, highly emotional family atmospheres and the use of cannabis are all associated with an increased risk of developing schizophrenia, though none has been shown to directly cause it.

Brain scans have shown a reduction in size of certain areas of the brain in schizophrenics, though it is not certain whether this is due to the disease or its treatment. Meanwhile, the successful use of drugs that block the neurotransmitter dopamine would suggest that schizophrenia is due to increased levels of dopamine in the brain.

Symptoms

An individual with schizophrenia may appear pre-occupied, suspicious, withdrawn, restless or absolutely still. These appearances make more sense when one understands the various symptoms experienced by psychotic individuals. The symptoms can be broken up into the following categories:

• False perceptions
• Disorders of thought content
• Disorders of thought processing
• Negative symptoms

False Perceptions

Perceptions are the things we perceive as happening in the world around us, based upon the input from our five senses. Hallucinations are a form of false perception that occur without any external stimuli but seem to come from outside the body. They are thus different from illusions, where a person mistakes a real stimulus for something it isn't¹, and pseudohallucinations, which come from within the 'mind's eye' and do not appear to be real.

Schizophrenics tend to experience auditory hallucinations: a voice may give a running commentary on their actions, the person's thoughts might be read out by a voice directly after they think them (thought echo), or they may hear voices discussing or arguing about them. Hallucinated voices giving instructions also occur but are less common.

A range of other forms of hallucination are possible, including odd sensations on or underneath the skin or involving the internal organs, odd smells and tastes, and visual hallucinations. It is worth noting that visual hallucinations are more commonly caused by 'organic' disease such as epilepsy, brain tumours and dementia, and may also be caused by psychoactive substance abuse.

Disorders of Thought Content

Disorders of thought content are those that lead to the production of abnormal beliefs. Delusions are abnormal beliefs that are held unshakably despite being logically incorrect, and which cannot be explained by the person's cultural background. Delusions may feature heavily in psychotic illnesses, and should be contrasted with overvalued ideas such as the fear of fatness seen in the eating disorders, and with the persistently intruding obsessions of OCD. With treatment, delusions may become less strongly held, in which case they are referred to as partial delusions.

Deluded individuals tend to have little insight into the fact that their belief is incorrect, and will often develop a series of interconnecting secondary delusions based around an initial primary delusion. Although they may be based on a misinterpretation of reality (delusional perceptions), primary delusions do not have any logical basis and are entirely due to the person's mental illness.

Delusions can be categorised in several ways. Whereas severely depressed or manic individuals may develop mood-congruent delusions that correlate with their current emotions, schizophrenics tend to have mood-incongruent delusions, though these may later lead to depression. Bizarre delusions are labelled as such because they are utterly impossible, or at least would seem so to everyone other than the schizophrenic. Finally, delusions can be categorised according to their content, with the following labels being used:

• Persecutory delusions – false beliefs that others are harming or otherwise conspiring against oneself.

• Grandiose delusions – false beliefs of importance or of having special powers.

• Delusions of reference – false beliefs that objects, people, events or media programmes have special meaning or are talking specifically about oneself.

• Delusions of misidentification – false belief that a close friend or family member has been replaced by an exact double (Capgras syndrome) or that strangers are in fact friends in disguise (Fregoli syndrome).

• Religious delusions – false beliefs with a religious flavour, such as the belief that one is a messenger from God.

• Delusions of love – false belief that another person is in love with oneself, which perseveres despite evidence to the contrary. The belief that a person of fame or high status is secretly in love with oneself is known as de Clérambault syndrome and is more common in women.

• Delusions of infidelity – an unshakable false belief that one's partner has been unfaithful, based upon paltry and non-specific evidence (aka Othello syndrome).

• Nihilistic delusions – false belief that one is dead or does not exist, or that nothing whatsoever actually exists. This should not be confused with nihilistic philosophy.

• Somatic delusions – false beliefs that one's body is malfunctioning or deteriorating in some way (aka hypochondriacal delusions).

• Delusions of infestation – false beliefs that one's body has been invaded by tiny visible organisms (Ekbom's syndrome).

• Delusions of passivity – false beliefs that one's feelings, thoughts or actions are being controlled by someone else. Thought withdrawal describes the belief that thoughts are being taken out of one's mind, thought insertion is the belief that thoughts are being put into one's mind, and thought broadcast is the belief that others can read one's thoughts or that one's thoughts are being broadcast to others.

It's worth noting that the word 'paranoid' does not refer to persecutory delusions alone, but includes all delusions referring to oneself.

Disorders of Thought Formation

Some psychotic individuals can also experience disorders of the way they think, and these are reflected by the way in which they speak. The least severe form is that of circumstantial speech, where the individual will eventually answer a question but will go round the houses and provide every tiny detail before getting to the point. Tangential speech may also occur, the difference being that the speaker never gets to the point, constantly flying off on tangents instead. A step up from circumstantial and tangential speech is loosening of association, in which the links between different thoughts become harder for the onlooker to follow. This can produce derailment, where the speaker suddenly shifts to a different topic of conversation, or knight's move thinking, so-called because the speaker's train of thought shifts constantly in the same manner as a knight does in chess. The most severe level of disordered thought is word salad, where every word spoken has some distant association with the last, but the sentences produced are absolute nonsense.

Other features of disordered thought formation can also occur:

• Flight of ideas – where a stream of related thoughts rushes through the person's mind.

• Thought blocking – where the person suddenly loses their flow of thought and cannot recall it.

• Irrelevant answers – where the person gives answers that have nothing to do with the questions asked.

• Neologisms  – where the person uses made-up words fashioned out of syllables from real words.

• Metonyms – where the person gives real words meanings not recognized by other people.

• Echolalia – where the person repeats words and phrases they have heard in a parrot fashion.

• Perseveration – where the person repeats the last thing they themselves said².

Disorders of thought formation, such as flight of ideas and circumstantial speech, can also occur in manic individuals.

Negative Symptoms

'Negative symptoms' are those that cause a deficit in an individual's activity, in contrast to the active production of the 'positive symptoms' listed above. Negative symptoms include a reduction in thinking and speaking (poverty of thought, poverty of speech and apathy), an absence of outward emotion (blunted affect), social isolation and self-neglect.

Psychomotor disturbances may occur, leading to difficulties with movement due to increased muscle stiffness or tremor. These signs³ are usually a side-effect of anti-psychotic medication, although distinctive signs will occasionally develop as a direct result of schizophrenia. This includes the various catatonic states:

• Catatonic stupor – a complete absence of voluntary movements and speech in an otherwise capable and alert person.

• Catatonic posturing – taking on a bizarre pose and maintaining it for a period of time.

• Catatonic rigidity – staying in the same position and resisting any attempts to be moved.

• Catatonic waxy flexibility – staying in the same position but allowing others to move one's body, following which the new pose is held.

• Catatonic excitement – excited and apparently pointless movements that are unaffected by external input.

• Catatonic negativism – apparently pointless refusal to follow any instruction to the point that the individual may do the opposite of what they are told.

Other psychomotor signs include imitation of other people's movements (echopraxia), complex repeated movements (mannerisms if with some apparent aim eg saluting, stereotypies if pointless eg rocking back and forth), and sudden involuntary movements or utterings (tics).

Schizophrenia

While there is no one symptom that defines schizophrenia, all of the symptoms mentioned above may occur. The ICD 10⁴ requirements for a diagnosis of schizophrenia are one or more of the following:

• Delusions of thought control (insertion, withdrawal or broadcast).
• Delusions of control (passivity) or delusional perceptions.
• Bizarre delusions.
• Auditory hallucinations (thought echo, running commentary, voices discussing self or voices coming from part of body).

These are known as first-rank symptoms, as defined by German psychiatrist Kurt Schneider in 1959. Alternatively, a diagnosis may be based on two or more of the following symptoms:

• Other hallucinations, provided they occur every day or are associated with overvalued ideas or delusions.
• Disorders of thought formation (loosening of association, neologisms).
• Catatonic symptoms.
• Negative symptoms.
• Behavioural changes (social withdrawal, lack of purpose, loss of interest in things).

Schizophrenia can be divided into subtypes depending upon which symptoms are dominant. Individuals presenting mainly with hallucinations and delusions are labelled as having paranoid schizophrenia, those with mainly disordered thought formation and negative behavioural symptoms are labelled with hebephrenic schizophrenia, and those rare cases with catatonic symptoms are labelled with catatonic schizophrenia. Not all cases are as clear-cut as this, and the term undifferentiated schizophrenia may be used. Meanwhile, residual schizophrenia describes a state of negative symptoms persisting for at least a year after the end of a psychotic episode.

Other Psychoses

There are a number of other diagnoses available for patients with psychotic symptoms:

• Acute psychotic disorders are those that last less than a month, or that have a rapid onset followed by a quick recovery. There are a number of diagnoses intended to cover those who do not fit the criteria for schizophrenia, but still have a clearly schizophrenia-like illness.

• Schizoaffective disorder refers to the simultaneous development of schizophrenia and an affective (mood) disorder, with both conditions on an equal footing. This should not be confused with the depression that some schizophrenics develop as a result of their condition.

• Delusional disorder refers to the holding of a set of delusions for at least three months with few or no other psychotic symptoms. Although it may persist for the rest of their lives, individuals with delusional disorder are usually able to function normally.

• Induced delusional disorder, aka folie á deux, refers to a situation where a psychotic individual induces their delusions in the mind of a person close to them. These delusions usually resolve when the two individuals are separated.

Note that psychotic illnesses can only be diagnosed once 'organic' causes (such as a brain tumour) and substance misuse have been excluded. Also, remember that depressed and manic individuals may experience mood-congruent delusions and hallucinations (see above).

Treatment of Schizophrenia

When an individual has an episode of schizophrenia it may be necessary for them to be 'sectioned' under the Mental Health Act 1983 and removed to a safe environment such as a mental health unit. Once the individual is stable, they can be provided with home leave and eventually be discharged for treatment in the community.

Initial drug treatment consists of an 'atypical' anti-psychotic such as risperidone, olanzapine or quetiapine. Atypicals are so-called because they have a lower side-effect profile and are better at treating negative symptoms than the older 'typical' anti-psychotics (eg haloperidol). Some individuals have treatment resistant schizophrenia, meaning that they fail to respond despite the sequential use of two anti-psychotics, one of which is atypical, for 6 - 8 weeks. These individuals are given clozapine, a more effective atypical that requires regular blood tests due to the risk of a rare life-threatening white cell disorder known as agranulocytosis. Other drugs used in schizophrenia include sedatives such as benzodiazepines, mood stabilisers such as lithium, and antidepressants. Electroconvulsive therapy tends only to be used in rare cases of severe catatonic schizophrenia.

Psychotherapy may be used in partially-recovered schizophrenics to help build insight into their condition, create a supportive family atmosphere for the individual, help reassure and support the individual and aid them in returning to normal life. Meanwhile, other support including day hospital attendance, financial support and social support are also considered once the individual is ready for discharge from hospital.

Prognosis

Good prognostic factors include being female, married, treated quickly, responding well to treatment, having paranoid schizophrenia, lacking negative symptoms, having a first episode later in life, developing the condition following a stressful life event, and having functioned well before developing the illness.

Around a fifth of individuals experiencing a first episode of schizophrenia will recover completely with no further episodes. However, half of all schizophrenics have repeated episodes leading to multiple hospitalisations and can suffer from depression and suicidal ideation. The lifespan of such persons is shortened by around ten years through a mixture of unhealthy living, accidents and suicide. Around 10% of schizophrenics will successfully kill themselves.