Schizophrenia vs Schizoaffective Disorder

Schizophrenia and schizoaffective disorders both belong to a group of mental illnesses known as ‘psychotic disorders’.^[1] Psychotic disorders are characterized by a variety of symptoms including delusions, hallucinations, strange thinking and speech and unusual behavior.

What is schizophrenia?

According to the Diagnostic and Statistical Manual of Mental Disorders ^[1], used by mental health professionals in the US to diagnose mental health problems, people with schizophrenia will experience two or more of the following symptoms, including at least one of the first two, for at least a month:

• Delusions – believing things that aren’t real
• Hallucinations – seeing, hearing, or perceivingthings that aren’t there
• Disorganized thinking and speech – switching topics quickly or giving odd answers to questions, for example
• Strange behavior – for example, childlike sillinessor agitation
• Catatonia – catatonic behvaior is when someone doesn’t respond to what is happening around them
• ‘Negative symptoms’ – an absence of standard human behavior and interaction, such as a lack of emotionsor a lack of motivation to do anything unless prompted.

Schizophrenia affects between 0.3 and 0.7 per cent of the population. Prevalence appears to be higher in urban areas and among some ethnic groups, such as African Americans.^[1]

What is schizoaffective disorder?

Schizoaffective disorder is essentially the presence of schizophrenia symptoms accompanied by either depression or mania.^[1]

The depression or mania needs to be present at the same time as schizophrenia-like symptoms, and co-exist for the majority of the time a person is unwell. However, schizophrenia-like symptoms must also persist outside of the depression or mania. This distinguishes it from other mental health problems such as independent periods of psychosis, major depression, or bipolar disorder.

Schizoaffective disorder is less common than schizophrenia, affecting about a third as many people as schizophrenia does.^[1]

How are schizophrenia and schizoaffective disorder similar?

Schizophrenia and schizoaffective disorder are similar in that they both include psychotic symptoms, which the person must experience for a long period of time.

How do they differ?

The key difference is that schizoaffective patients will experience a major mood episode – either a manic episode or the depressive type – at the same time as experiencing schizophrenia symptoms.

Someone with schizophrenia can experience periods of depression or mania but they will be short-lived and only form a small part of the person’s mental illness. A person with schizoaffective disorder will have depression or mania for most of the time they are unwell with psychotic symptoms.

In addition, while schizophrenia can only be diagnosed if the psychotic symptoms have a significant impact on a person’s life, this is not necessary for a diagnosis of schizoaffective disorder.

The ‘negative symptoms’ of schizophrenia may be less pronounced in someone with schizoaffective disorder, who may also have more insight into their mental health condition than someone with schizophrenia.

What are the causes?

Research has found some genes linked to an increased risk of schizophrenia. Studies also suggest that factors relating to pregnancy and birth can increase the risk including the age of the father, stress during pregnancy, when in the year a person was born, low blood oxygen levels, and the mother’s health problems.^[1]

It is not known whether schizoaffective disorder is different from schizophrenia when it comes to, for example, brain abnormalities or genetics. Studies show the risk of schizoaffective disorder appears to be higher in people with a close relative with schizophrenia, schizoaffective disorder or bipolar disorder.^[1]

Can you have both conditions?

No. As schizoaffective disorder essentially combines symptoms of schizophrenia with some additional symptoms, a person cannot be diagnosed with both at the same time. However, a person may change diagnosis from one to the other. If depression or mania symptoms begin and persist in someone diagnosed with schizophrenia, they may be diagnosed with schizoaffective disorder. Conversely, if some with schizoaffective disorder finds their symptoms of depression or mania disappear and don’t reoccur, they may have their diagnosis changed to schizophrenia.^[1]

People with schizophrenia and schizoaffective disorder can experience other mental health problems alongside their diagnosis. Substance misuse problems and anxiety disorder are particularly common in patients with schizophrenia or schizoaffective disorder.

How are they diagnosed?

Diagnosis is done by a doctor or other mental health professional following a psychological evaluation, which includes discussion of signs and symptoms, a review of medical history and questionnaires.

Schizophrenia can be diagnosed if a person has experienced symptoms for at least a month. For schizoaffective disorder, it may be necessary to monitor the person for longer to assess the overlap between psychotic and mood-related symptoms.^[1]

Treatment for schizophrenia and schizoaffective disorder

Both schizophrenia and schizoaffective disorder are primarily treated with antipsychotic medication, which helps to alleviate the symptoms of psychosis. People with schizoaffective disorder may also be prescribed a separate medication to help with mood-related symptoms. Effective treatment options include antidepressant drugs for depression, or a mood stabilizer for mania.^[2]

Psychotherapy, such as cognitive behavioral therapy (CBT) might also help with managing symptoms.^[2]