How Schizoaffective Disorder Is Diagnosed

The diagnosis of schizoaffective disorder is based on recurrent symptoms of psychosis and mood disturbance. Diagnostic and Statistical Manual of Mental Disorders (DSM-5), the guide used by mental health professionals, includes specific criteria used to diagnose this condition. 

Schizoaffective disorder has features similar to those of several other disorders, including schizophrenia, bipolar disorder, and certain types of depression. Depending on your symptoms and physical examination, other conditions may need to be considered and ruled out before a definitive diagnosis of schizoaffective disorder is made.

Professional Screenings

Several questionnaires have been considered as potential screening tools to identify schizoaffective disorder.

The Self-assessment of Negative Symptoms (SNS) includes questions about social withdrawal, diminished emotional range, avolition (lack of motivation), anhedonia (inability to feel pleasure), and alogia (lack of speech and thoughts).

You would take this test in your healthcare provider’s or therapist’s office by responding to 20 questions about your symptoms. SNS is a useful screening tool for certain symptoms of schizophrenia and schizoaffective disorder.

The Patient Assessment Questionnaire (PAQ) is a 53-item questionnaire that includes questions about general distress, side effects, psychotic symptoms, cognitive symptoms, and sleep.

You would respond to the questions by taking the test in your healthcare provider’s or therapist’s office. The responses may be helpful as a preliminary screening for schizophrenia and schizoaffective disorder.

The most important tool in diagnosing schizoaffective disorder is a formal psychiatric evaluation using the DSM criteria for the disorder.

Psychiatric Evaluation and Medical Tests

Your evaluation for symptoms of schizoaffective disorder will begin with your healthcare provider asking about your symptom history, medical history, and your family medical and psychiatric history.

You will have a physical examination, which includes a neurological and mental status examination. Based on the outcome of this preliminary assessment, you might need to have further diagnostic testing.

Laboratory tests can’t confirm a diagnosis of schizoaffective disorder, but they can help determine whether you have another medical condition that presents with similar symptoms.

Signs and symptoms that can occur with schizoaffective disorder include:

• A lack of interaction with others
• A lack of facial expression
• Crying or visibly sad 
• Extreme excitement 
• Restlessness
• Speaking rapidly 
• Sharing many ideas rapidly 
• Paranoia 
• Describing sensations that aren’t there (such as seeing or hearing things that aren’t there) 
• Describing delusions (beliefs that aren’t true)
• Unusual or disheveled appearance 

Often, close friends or family members can help in your evaluation by describing what they have observed of your symptoms and behavior over time.

If there is concern about a medical or neurological condition causing or contributing to your symptoms, your healthcare provider might order tests, including:

• Complete blood count (CBC): Can show signs of an infection or anemia
• Blood electrolyte levels: Can detect electrolyte or metabolic problems
• Urine drug screen: Can show evidence of certain medications or illicit drugs
• Hormone levels: Thyroid function tests or adrenal hormone levels
• Brain imaging: Can detect brain injury, stroke, tumors
• Lumbar puncture: Can detect signs of infection or inflammation
• Electroencephalogram (EEG): Can detect seizures or signs of brain toxicity

Self-Checks/At-Home Testing

It’s helpful if you try to keep track of your symptoms over time. However, a lack of insight about symptoms is very common with schizoaffective disorder. You might benefit from having a trusted friend or family member help you monitor and track your symptoms. 

Signs and symptoms that could indicate schizoaffective disorder include: 

• Inability to sleep 
• Sleeping too much 
• Risk-taking behavior 
• Extreme sadness 
• Thinking about suicide or self-harm 
• Weight loss or weight gain
• Unable to focus 
• Seeing, hearing, or smelling unusual things or things that aren’t there 
• Feeling that people are trying to harm you 
• Frequent agitation, anger, or arguments

It may be difficult to recognize that you have some of these symptoms. Rest assured that when you talk to your healthcare provider, you will go through a diagnostic process that will help figure out the cause of the disruption that is happening in your life. 

Determining Subtypes

There are two subtypes of schizoaffective disorder. They each involve symptoms of psychosis, but they differ based on the pattern of mood symptoms.

Subtypes of schizoaffective disorder include:

• Depressive type: With the depressive subtype, symptoms of schizophrenia occur, as well as symptoms of major depressive disorder. 
• Bipolar type: With the bipolar subtype, symptoms of schizophrenia and manic episodes occur, and depressive symptoms can occur.

The DSM-5 criteria for the diagnosis of schizoaffective disorder include several components. All four of the following (A, B, C, and D) must be present for a diagnosis of schizoaffective disorder:

• A: A major mood episode that is concurrent with at least two of the following: hallucinations, delusions, disorganized speech, disorganized behavior, negative symptoms (can include withdrawal from others, catatonic behavior)
• B: Symptoms of schizophrenia for at least two weeks without accompanied mood symptoms
• C: Depression and/or mania throughout most of the illness
• D: Symptoms are not due to another cause, such as substances or a medical condition

Differential Diagnosis

Several psychiatric and neurological conditions can cause psychosis or hallucinations and mood changes. Some of these are considered as possibilities when symptoms of schizoaffective disorder are being evaluated.

Each of these can have characteristics that may help distinguish the conditions. Because the effects of schizoaffective disorder can be intermittent and episodic, it can take months or years for the pattern and variability of symptoms to become clear. 

Conditions that can manifest similarly to schizoaffective disorder include: 

• Schizophrenia: A psychiatric disorder characterized by psychosis without substantial mood symptoms
• Bipolar disorder: A condition characterized by mania, hypomania, depression, and possible episodes of psychosis
• Major depressive disorder (MDD): A condition characterized by severe depressive episodes that can be associated with psychosis
• Huntington’s disease: A hereditary type of dementia that may be associated with symptoms of psychosis
• Progressive supranuclear palsy (PSP): A progressive dementia with symptoms of emotional lability
• Intoxication/drug use: Can cause various symptoms that may resemble symptoms of psychosis or a mood disorder
• Brain disorder or brain injury (such as stroke, head trauma, brain tumor, or brain infection): Can cause changes in behavior that could resemble some of the effects of schizoaffective disorder
• Systemic illness (such as severe infection, metabolic condition, or organ failure): Can cause changes in mood and/or behavior

A Word From Verywell

The process of diagnosing schizoaffective disorder can be stressful. You and your loved ones could be experiencing substantial distress due to the symptoms. It can sometimes take years for your diagnosis to become completely clear.

Once you are diagnosed with schizoaffective disorder, getting treatment can help alleviate symptoms and the impact of the illness on your life.