An Overview of Schizophrenia

Schizophrenia is a disorder characterised by severe disturbances in thinking, emotion and behaviour that are disruptive to a person’s life.  Schizophrenia is characterised by changes in mental function where thoughts and perceptions become disordered, and there is a loss of contact with reality.

The term schizophrenia is Greek in origin meaning “split mind”. However schizophrenia does not refer to a split personality disorder and people with schizophrenia do not have separate personalities. Schizophrenia is more accurately defined as a “schism” between thought, emotion and behaviour.

About one person in 100 develops schizophrenia. Men and women are affected equally; however men tend to have their first episode in their late teens or early 20s whereas the onset for women is usually slightly later. In most cases, the illness starts so gradually that symptoms are barely noticeable, although in some instances the onset can be rapid.


Schizophrenia has three phases – prodromal (or beginning), acute (or active) and recovery (or residual). These phases tend to occur in order and cycle throughout the course of the illness. People who develop schizophrenia may have one or many psychotic episodes during their lifetime.

Prodromal Phase: During the initial onset of schizophrenia, there are barely noticeable changes in the way a person thinks, feels and behaves. For example, the person may start to perceive things differently, withdraw from others, become superstitious, work or study may deteriorate, and he or she can become irritable and have difficulty concentrating or remembering things. This phase usually occurs between ages 15 to 25 in males and ages 25 to 35 in females.

Acute Phase: During the next phase, clearly psychotic symptoms are experienced. The term “formal thought disorder” is often used as an overall term to describe these acute or ‘florid’ symptoms.

Recovery Phase: Following an active psychotic episode, florid symptoms recede and depression may develop as people regain insight into their behaviour and begin to realise the impact the illness has had on their lives. For some people, residual symptoms may remain and their ability to function effectively can decrease after each active phase.

It is therefore important to avoid relapses where possible by following prescribed treatment. It is difficult to predict at the onset of the illness how fully a person will recover, however schizophrenia is treatable and most people do recover.

(American Psychiatric Association, 2000)

Symptoms of Schizophrenia

Schizophrenia includes both positive and negative symptoms. Positive symptoms are the more active manifestations of abnormal behaviour, whereas negative symptoms involve deficits in normal behaviour.

Positive Symptoms

Delusions: Delusions are a disorder of thought content – a false belief that has no evidence to support it; however the person cannot be persuaded that the belief is incorrect. There are several types of delusions:

  • Persecutory Delusions: The person feels he or she is being plotted or discriminated against, spied on, threatened, attacked or deliberately victimised. This is the most common form of psychotic delusion.
  • Delusions of Reference: Also common, these symptoms occur when a person attaches special personal meaning to the actions of other people or objects when there is no information to confirm this, for example they may believe television sets are talking to them or that people are sending thoughts to them.
  • Delusions of Grandeur: The person believes he or she has enormously superior characteristics or is a person of great power or fame.
  • Thought Broadcasting: Similar to telepathy, the person believes that other people are able to hear their thoughts.
  • Thought Insertion: In this case the person believes that thoughts are being put into their head by others, i.e. that they can hear the thoughts of other people.
  • Thought Blocking/Thought Withdrawal: This involves the belief that others are stealing the person’s thoughts.

Hallucinations: People with schizophrenia often experience hallucinations – false perceptions of sensory stimuli. Hallucinations can involve any of the senses; however auditory hallucinations are the most common, for example hearing an instruction to do something, referred to as a “command hallucination”. Hallucinations occur when the person is fully conscious and appear to them to come from an outside source.

Disordered Speech: People with formal thought disorders can feel enormous confusion which makes communication very difficult. Often these symptoms take some form of disorganised speech:

  • Clang Associations: The person chooses words because they sound alike rather than for their meaning.
  • Tangentiality: The person’s ideas are only loosely connected to the topic, i.e. there are “loose associations” between expressed ideas and one thought or statement does not logically follow the other.
  • Derailment of Speech: The person’s ideas rapidly shift from one subject to another and are not related at all, however he or she believes the incoherent statements make perfect sense.
  • Word Salad: The person’s language can become so disordered as to be incomprehensible, a senseless jumble of words.
  • Magical Thinking: The person believes their thoughts are the cause of things that happen.
  • Neologisms: The person makes up new words that have meaning only to them.
  • Perseveration: The person will repeat words and statements over and over.

Disorganised Behaviour: Disorganised symptoms include actions that are not goal-directed and appear bizarre. Examples include laughing inappropriately or repeatedly making signs in the air. Motor dysfunctions, such as pacing repeatedly or rigidly holding postures for unusual lengths of time (also known as catatonia) also fall into this category.

Catatonic behaviours are characterised by a marked decrease in reaction to the immediate surrounding environment. They usually take the form of motionless, rigid or bizarre postures, or aimless and excessive motor activity.

Negative Symptoms

Negative symptoms are those that result in a loss of normal function. These symptoms often persist in the lives of people with schizophrenia during periods when positive symptoms are no longer present. Some of these include:

Flat Affect: People with affective flattening show little emotion and can seem to be wearing a mask. They have vacant eyes and a toneless voice, and show little response to activities going on around them. Flattened affect is thought to be more of a difficulty with expressing emotions, rather than with experiencing them.

Avolition: Avolition is an inability to initiate and persist in important activities. This is sometimes referred to as “apathy”.

Alogia: Alogia is an absence of content in communication. People with this deficit will respond to questions with very brief replies or their responses will be slow or delayed. This symptom is also referred to as “poverty of speech”.

Other negative symptoms include:

  • Low energy
  • Lack of interest in life
  • Inappropriate social skills or lack of interest in socialising
  • Inability or lack of interest in making or keeping friends
  • Social isolation.

(American Psychiatric Association, 2000)

Types of Schizophrenia

Schizophrenia can take a number of different forms. Each type is distinguished by the pattern of symptoms that occur.

Paranoid: Paranoid schizophrenia is the most common type of schizophrenia. The predominant symptoms are delusions and auditory hallucinations; however the person’s cognitive functioning and mood remain relatively intact.

The person will often experience highly elaborate delusions of persecution or grandeur while continuing to function effectively. The delusions are usually accompanied by hallucinatory voices that threaten or give commands, or by auditory hallucinations such as whistling, humming, or laughing. None of the following symptoms are prominent:

  • Disordered speech
  • Disorganised or catatonic behaviour
  • Flat or inappropriate affect.

Disorganised: Disorganised schizophrenia is characterised by the early age of onset and the presence of pronounced thought and speech disorder, altered affect and strange behaviour. Symptoms include auditory or visual hallucinations.

The person’s emotional responses are usually inappropriate and their personal appearance can be unpredictable. Activities are aimless and non-constructive, making effective functioning difficult. In contrast to paranoid schizophrenia, the most prominent symptoms here are:

  • Disordered speech
  • Disorganised behaviour
  • Flat or inappropriate affect.

Catatonic: People with catatonic schizophrenia exhibit physical symptoms such as immobility, excessive movement or bizarre postures. The following symptoms are common:

  • Motor immobility or excessive motor activity
  • Extreme mutism
  • Peculiarities of voluntary movement.

Undifferentiated Type: This is a type in which active symptoms are present but the criteria is not met for the paranoid, disorganised or catatonic type diagnoses.

Residual Type: This involves a pattern of symptoms in which there is absence of prominent delusions, hallucinations, disorganised speech, and disorganised or catatonic behaviour.

However there is continuing evidence of disturbance, as indicated by the presence of negative symptoms. Alternatively, there may be two or more positive symptoms present in an attenuated form (eg. odd beliefs, unusual perceptual experiences).

All types of schizophrenia have specific criteria which must be met for a diagnosis to be given. Time of onset as well as duration of symptoms are also taken into account.

(American Psychiatric Association, 2000)

Diagnostic Criteria

In order for a person to receive a diagnosis of schizophrenia, they must have at least two of the following symptoms, each present for a significant portion of time during a one month period (or less if successfully treated):

  • delusions
  • hallucinations
  • disorganised speech (eg. frequent derailment or incoherence)
  • grossly disorganised or catatonic behaviour
  • negative symptoms, i.e. affective flattening, alogia or avolition.

However only one of these symptoms is required if the person’s delusions are bizarre or their hallucinations involve either a voice which gives a running commentary on the person’s behaviour or thoughts, or if two or more voices are conversing with each other.

For a significant portion of the time since the onset of the disturbance, the person needs to have experienced social and occupational dysfunction, ie.  one or more major areas of functioning such as work, relationships or self-care are markedly below the level achieved prior to the onset. When the onset is in childhood or adolescence, the criteria is a failure to achieve expected levels of interpersonal, academic, or occupational achievement for the person’s age.

The active symptoms of schizophrenia must be present for at least six months (unless successfully treated, in which case the criteria is one month). The six month period must include at least one month of acute phase symptoms, such as delusions, hallucinations, disorganised speech, grossly disorganised or catatonic behaviour or negative symptoms, and may include periods of prodromal or residual symptoms. During prodromal or residual periods, the signs of the disturbance may be manifested by only negative symptoms, or by two or more acute phase symptoms in an attenuated form (eg. odd beliefs, unusual perceptual experiences).

Before a diagnosis of schizophrenia is made, a diagnosis of schizoaffective disorder or mood disorder with psychotic features needs to be ruled out. The disturbance must also not be a result of the direct physiological effects of a substance (eg. an illicit or prescribed drug) or a general medical condition.

If there is a history of autistic disorder or another pervasive developmental disorder, the additional diagnosis of schizophrenia is made only if prominent delusions or hallucinations are also present for at least a month (or less if successfully treated).

(American Psychiatric Association, 2000)