Schizophrenia and related disorders

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CHAPTER 5 Schizophrenia and related disorders

Schizophrenia is a disorder which affects roughly 1 in 200 people, and which can have a profound effect upon the individual and their families. The term schizophrenia refers to a ‘splitting of the psychic functions’, and not, as is commonly believed, to a ‘split personality’. Key aspects of the disorder are shown in Box 5.1.

Clinical features

The signs and symptoms of the disorder are most usefully divided into:

positive symptoms: delusions (fixed false beliefs held with tenacity and not understandable in terms of the sociocultural context) and hallucinations (false perceptions which can occur in any sensory modality, but with auditory hallucinations being most common)

negative symptoms: restricted or blunted affect (decreased range of facial expression); paucity of thought content; and apathetic social withdrawal

disorganisation symptoms: formal thought disorder (disorganised thoughts, manifested by disjointed speech); disorganised behaviour; and inappropriate affect (e.g. smiling when discussing a sad event), and

cognitive impairment (see below).

There is no specific laboratory or radiological test for schizophrenia, and none of the signs or symptoms outlined above are pathognomonic. However, the ‘first rank’ symptoms elucidated by Schneider (Box 5.2) have some degree of diagnostic specificity, and are useful to ask for in the clinical interview.

BOX 5.2 Schneider’s ‘first rank’ symptoms of schizophrenia

Auditory hallucinatory experiences

These include:

• third person auditory hallucinations: two or more voices discussing the individual in the third person (he, she, it); often derogatory/persecutory

• running commentary: a voice commenting on the person’s actual actions, in the third person, and

• audible thoughts (gedankenlaudwerten): hearing one’s own thoughts out loud.

Delusional perception

There is a normal percept to which an ‘un-understandable’ delusional attribution is given.

Passivity phenomena

This is a series of phenomena where the person experiences their will, actions, affect or bodily (somatic) functions being ‘taken over’ by some alien influence. It is an ‘as if’ phenomenon, such as: ‘It is as though my actions are controlled by a robot; I feel like a puppet on a string.’

Permeability of ego boundaries

This includes:

• thought insertion: not all thoughts in one’s mind are one’s own; thoughts are being ‘put into’ the person’s mind; there may be secondary elaboration (e.g. ‘An intergalactic machine is putting thoughts into my mind’)

• thought withdrawal: this is the reverse of thought insertion; it may be experienced as the mind transiently ‘going blank’, and

• thought broadcast: a feeling that thoughts dissipate out of the person’s mind, and are ‘shared’ by others; it is more than just feeling others can read their mind.

(Castle & Buckley 2008, with permission)

Negative symptoms can sometimes be ‘mimicked’ by depression, positive symptoms or the extrapyramidal side effects of antipsychotic medication. It is always important to treat the underlying cause, as shown in Table 5.1.

TABLE 5.1 Primary and secondary negative symptoms, and treatment

		Management
Primary		Use atypical antipsychotic; consider adjunctive treatments; if persistent, consider clozapine
Secondary	To depression	Antidepressant medication (SSRI or mirtazapine)
	To positive symptoms	Optimise treatment of positive symptoms: pharmacological and psychosocial approaches should be explored
	To D2 receptor blockade	Consider atypical antipsychotic; if persistent extrapyramidal side effects on atypical antipsychotic, consider adjunctive anticholinergic agent

(Castle & Buckley 2008, with permission)

Not all signs and symptoms occur in any one individual at any one time: different patients show different features and these might change over the course of the illness. Table 5.2 shows the cardinal features of schizophrenia according to DSM–IVTR and ICD–10. It will be noted that there is considerable overlap between these two constructs: the main difference is that DSM–IVTR requires a 6-month duration: disorders with the characteristic symptoms but shorter duration are labelled schizophreniform disorder.

TABLE 5.2 DSM–IVTR and ICD–10 diagnoses of schizophrenia

DSM–IVTR (synopsis)	ICD–10 (synopsis)
Symptoms (at least 1 month unless successfully treated): • delusions • hallucinations • disorganised speech • disorganised or catatonic behaviour, and • negative symptoms

Symptoms:

• at least one of: thought echo, insertion, withdrawal, broadcast

• passivity phenomena or delusional perception, and

• third person conversing or running commentary hallucinations

At least two symptoms required, unless:

• delusions are bizarre, and

• hallucinations are third person conversing or running commentary

At least two of:

• persistent hallucinations in any modality, with delusions

• disorganised speech

• catatonia, and

• negative symptoms (must be ‘primary’)

Social/occupational dysfunction:

• work

• interpersonal relations, and

• self-care

Duration: 6 months at least Duration: 1 month at least Exclusions:

• schizoaffective disorder

• bipolar disorder

• general medical condition, and

• substance-induced

Exclusions:

• mood disorder

• organic brain disease, and

• alcohol/drug-related intoxication

(Castle & Buckley 2008, with permission)

Differential diagnosis

‘Organic’ psychoses

Schizophrenia cannot be diagnosed if there are clear organic factors causing the symptoms and signs: this is labelled an organic psychosis. Exclusion of reversible organic causes (e.g. brain tumour) is obviously important in clinical practice, but it can be much more difficult to assess the role of illicit substances, which are commonly used by people with schizophrenia. A label of drug-induced psychosis is only appropriate if there is:

a clear temporal sequence between drug exposure and onset of symptoms

a resolution of symptoms on cessation of the drug, and

a relatively short duration of symptoms (certainly under 1 month).

People with established schizophrenia are vulnerable to relapse if they use drugs such as cannabis: the term drug-precipitated relapse is a more appropriate term in such cases.

Schizoaffective disorder

If there are clear affective and psychotic symptoms which occur at different times over the course of illness, a label of schizoaffective disorder is applied. There is some debate about the validity of this diagnosis and the boundaries are vague.

Delusional disorder

This group of disorders is characterised by well-circumscribed delusions in the absence of prominent hallucinations or negative or disorganisation symptoms. The delusional content is ‘understandable’, such as beliefs about having a disease (also termed monosymptomatic hypochondriacal delusions or delusional disorder, somatic subtype) or having an unfaithful partner (delusional jealousy, or Othello syndrome).

Pervasive developmental disorders

Pervasive developmental disorders (e.g. autism, Asperger’s syndrome (see Ch 16)) are characterised by abnormalities in social interactions, and a restricted and stereotyped range of interests and activities, evident from before 3 years of age.

Axis II disorders

Some of the cluster A DSM–IVTR Axis II (personality) disorders (see Ch 12) could be considered formes fruste of schizophrenia. The most obvious is schizotypal personality disorder, characterised by longstanding eccentricity, social withdrawal and odd beliefs. It is placed on Axis II in DSM–IVTR, but is probably genetically linked to schizophrenia, and sometimes evolves into full-blown schizophrenia.