Schizoaffective disorder is a condition in which a person meets the criteria for both schizophrenia and a mood disorder.

The term "schizoaffective disorder" was introduced in 1933 by a doctor who determined that some patients showed symptoms different enough from schizophrenia to warrant a separate diagnosis. They experienced psychosis — such as hallucinations or delusions, characteristic of schizophrenia — and also had symptoms of elevated or depressed mood.

Untreated, people with schizoaffective disorder may lead lonely lives and have trouble holding down a job or attending school. Or, they may rely heavily on family or psychiatric group homes, provided a diagnosis is made. With treatment, the prognosis for people with schizoaffective disorder seems to be better than for people with schizophrenia alone, and not as good as for people with a mood disorder alone.

Experts still debate whether schizoaffective disorder should be treated as a distinct disorder. Attitudes have ranged from regarding the condition simply as schizophrenia with some mood symptoms — to viewing it as a separate disease with distinct symptoms and treatments.

The symptoms of schizoaffective disorder vary from person to person. Generally, people who have the condition experience psychotic symptoms — such as hallucinations, disorganized thinking and paranoid thoughts — as well as a mood disturbance such as depressed or manic mood. They tend to be very antisocial and shunned by the people around them.

Psychotic features and mood disturbances may occur at the same time or may appear on and off interchangeably. The course of the schizoaffective disorder usually features cycles of severe symptoms followed by an improved outlook. To establish a diagnosis, a person must have demonstrated, at some point, delusions or hallucinations for at least two weeks without evidence of mood disorder symptoms.

Most commonly, the mood disorder accompanying the schizophrenic features is either bipolar disorder (bipolar-type schizoaffective) or depression (depressive-type schizoaffective).

Signs and symptoms of schizoaffective disorder may include:

• Strange or unusual thoughts or perceptions
• Paranoid thoughts and ideas
• Delusions — having false, fixed beliefs
• Hallucinations, such as hearing voices
• Unclear or confused thoughts (disorganized thinking)
• Bouts of depression
• Manic mood, or a sudden increase in energy and behavioral displays that are out of character
• Irritability and poor temper control
• Thoughts of suicide or homicide
• Irrelevant or incoherent speech
• Lack of response, or an extreme agitation that's not influenced by the environment (catatonic behavior)
• Deficits in attention and memory
• Lack of concern about hygiene and physical appearance
• Changes in energy and appetite
• Sleep disturbances, such as difficulty falling asleep or staying asleep

Schizoaffective disorder, like schizophrenia, appears to have distinct genetic links. It's unknown exactly what causes the disorder, but some experts believe it involves brain chemistry, such as an imbalance of serotonin and dopamine in the brain. Serotonin and dopamine are neurotransmitters — chemicals that help relay electronic signals in the brain — and help regulate mood.

Other experts have speculated whether fetal exposure to toxins or viral illness, or even birth complications, may play a role.

Schizoaffective disorder is thought to be a neurodevelopmental disorder — which involves delays or variations in the way a child's brain develops — like schizophrenia. Genetics play a role in development of the disorder, and people with relatives who have schizoaffective disorder are more likely to develop this condition. Environmental factors may also be involved.

Older people are more likely to have the depressive-type schizoaffective disorder, while younger people tend toward the bipolar type. Men with schizoaffective disorder are thought to exhibit a greater incidence of antisocial personality traits.

Factors that increase the risk of developing the schizoaffective disorder include:

• Having a relative who has schizophrenia
• Having a relative who has a mood disorder
• Having a relative who has schizoaffective disorder
• Being at risk of developing schizophrenia

If you suspect a friend or loved one may have schizoaffective disorder, be on the lookout for symptoms of psychosis as well as an underlying mood disorder.

People with schizoaffective disorder aren't likely to seek treatment. You might gently suggest that the person seek medical attention, starting with a primary care physician or mental health professional. Be prepared to accompany the person if necessary.

Diagnosis of schizoaffective disorder comes after a thorough clinical review. Should the doctor suspect a psychiatric condition, he or she might take a complete medical, psychiatric and social history and also ask about symptoms and mental well-being. A physical examination can help rule out other conditions, and a mental health professional will likely be consulted.

A diagnosis of schizoaffective disorder comes when a person has features of both schizophrenia and a mood disorder, but doesn't meet the diagnosis for either alone.

People may receive a diagnosis of schizoaffective disorder if they:

• Have schizophrenia along with mood symptoms
• Have a mood disorder along with symptoms of schizophrenia
• Have both a mood disorder and schizophrenia
• Have a psychotic condition other than schizophrenia, plus a mood disorder

Also, diagnosis requires that the condition is not due to the direct effects of a substance or due to a general medical condition.

In addition, the person must never have met the criteria for any other schizophrenic disorder. It's possible that symptoms may be mimicked by other medical conditions, such as steroid use, Cushing's syndrome, HIV-related illness, temporal lobe epilepsy, neurosyphilis, thyroid or parathyroid problems, alcohol or other drug abuse or dependence, and metabolic syndrome.

People with schizoaffective disorder are at an increased risk of:

• Developing schizophrenia
• Having major depression
• Having bipolar disorder

In addition, complications that may directly or indirectly accompany these conditions also may be experienced with schizoaffective disorder.

People with schizoaffective disorder generally respond best to a combination of medications and counseling. The exact regimen varies depending on the type and severity of symptoms, and whether the disorder is depressive-type or bipolar-type.

In general, doctors prescribe medications to alleviate psychotic symptoms, stabilize mood and treat depression. Meanwhile, psychotherapy can help curb distorted thoughts, teach appropriate social skills and diminish social isolation.

Medications may include:

• Antipsychotics. Also called neuroleptics, doctors prescribe these medications to alleviate psychotic symptoms, such as delusions, paranoia and hallucinations. Antipsychotic medications include clozapine (Clozaril), risperidone (Risperdal) and olanzapine (Zyprexa).
• Mood-stabilizing medications. When the schizoaffective disorder is bipolar-type, mood stabilizers can level out the highs and lows of bipolar disorder, also known as manic depression. People with bipolar disorder have episodes of mania and depressed mood. Examples of mood stabilizers include lithium (Eskalith, Lithobid) and divalproex (Depakote).
• Antidepressants. When depression is the underlying mood disorder, antidepressants can alleviate feelings of sadness, hopelessness, or difficulty with sleep and concentration. Common medications include citalopram (Celexa), fluoxetine (Prozac) and escitalopram (Lexapro).

Nonmedication therapy may include:

• Psychotherapy and counseling. Building a trusting relationship in therapy can help people with schizoaffective disorder better understand their condition and feel hopeful about their future. Effective sessions focus on real-life plans, problems and relationships. New skills and behaviors specific to settings, such as the home or workplace, also may be introduced.
• Family or group therapy. Treatment can be more effective when people with schizoaffective disorder are able to discuss their real-life problems with others. Supportive group settings can also help decrease social isolation and provide a reality check during periods of psychosis.

In general, people with schizoaffective disorder have a better prognosis than people with schizophrenia, but not as good as people with mood disorders only. However, long-term treatment is necessary, and the prognosis varies from person to person.