How Bipolar Disorder and Schizophrenia Differ

Bipolar disorder and schizophrenia share similar aspects, but schizophrenia is characterized by continuous or relapsing episodes of psychosis, while bipolar disorder is a mood disorder that can sometimes manifest with psychotic symptoms. Because they sometimes present similarly, these disorders may be mistaken for each other.

Brief definitions of these disorders are as follows:

• Bipolar disorder is a mood disorder characterized by episodes of depression and episodes of mania or hypomania.
• Schizophrenia is a psychiatric condition characterized by recurrent hallucinations (false sensations) and/or delusions (false beliefs), as well as impaired functioning.
• Schizoaffective disorder is a psychiatric condition characterized by episodes of psychosis along with and independent from mood disorder symptoms. A depressive type of schizoaffective disorder may be diagnosed when major depression occurs, and a bipolar type of schizoaffective disorder is characterized by bouts of mania.

Symptoms

If you have bipolar disorder, schizophrenia, or schizoaffective disorder, you may recognize many of your symptoms in descriptions of these conditions. However, there are variations in the symptoms you might experience.

The symptoms of schizophrenia and bipolar disorder can vary by person; no two cases are exactly alike.

Bipolar Disorder

The symptoms of bipolar disorder include clinically significant episodes of depression and hypomania and/or mania.

Symptoms of depression in bipolar disorder include:

• Sadness
• Lack of interest in things previously enjoyed
• Feelings of worthlessness
• Changes in appetite
• A sense of hopelessness and thoughts of suicide

Symptoms of mania in bipolar disorder include:

• Restlessness, inability to fall asleep
• Racing thoughts
• Elevated or irritable moods
• Unrealistic planning
• Overestimation of personal abilities
• Risk-taking

Mixed affective episodes occur when mania and depression occur at the same time. For example, a person may feel hopeless and could also have racing thoughts or risk-taking behavior.  

Schizophrenia

Schizophrenia is characterized by dissociation from reality, in the form of hallucinations, delusions, or disorganization. Negative symptoms, which include behaviors of impaired emotional expression and functioning, are a major component of this disorder as well. And cognitive symptoms, such as memory impairment, can affect a person’s ability to take care of themselves.  

Positive symptoms:

• Delusions and/or hallucinations
• Paranoia
• Agitation
• Disorganized speech
• Disorganized behavior

Negative symptoms:

• Apathy (lack of interest)
• Withdrawal from others
• Isolation
• Lack of emotional expression
• Excessive sleeping

Cognitive deficits:

• Diminished attention
• Impaired memory and learning
• Difficulty thinking and problem solving

Schizoaffective disorder includes the symptoms of schizophrenia, but a person who has schizoaffective disorder will also experience prolonged and persistent mood symptoms.

Causes

Bipolar disorder and schizophrenia are each believed to stem from genetic, biological, and environmental causes, although there are key differences.

Bipolar disorder affects approximately 2% of the population. Schizophrenia affects approximately 1% of the population. Schizoaffective disorder is much less common than either bipolar disorder or schizophrenia, with an estimated prevalence of approximately 0.3% of the population.

The average age of onset of symptoms for each of these conditions is in a person’s early 20s. The range of symptom onset is wider for bipolar disorder.

Genetic

There appears to be a strong genetic component contributing to the development of both schizophrenia and bipolar disorder.

Twin studies show that monozygotic (identical) twins are more likely to share a diagnosis of schizophrenia than dizygotic (fraternal, not identical) twins. This also correlates with alterations in the connectivity between certain structures of the brain that researchers believe to be strongly influenced by genetics. 

Bipolar disorder is impacted by genetic factors, and twin studies show a higher correlation of the diagnosis between identical twins than nonidentical twins. This is associated with lower volume in certain areas of the brain.

Biology

Prenatal issues are associated with the development of schizophrenia, but have not been found to be firmly linked to the development of bipolar disorder.

Maternal emotional stress, infections, birth complications, low oxygen level, and fetal distress are associated with an increased risk of subsequent development of schizophrenia.

Environment

A person’s community and environment play a role in the risk of bipolar disorder, as well as schizophrenia. Experts suggest that environmental factors do not cause these conditions, but that they can contribute to symptoms in people who are genetically vulnerable.

Researchers propose that exposure to substance abuse and/or excessive stress can induce metabolic changes in the body that amplify expression of the genetic factors that contribute to these disorders—possibly precipitating the brain changes that lead to the clinical effects.

Contributing environmental factors include childhood trauma, social isolation, and substance abuse.

Urbanicity is one of the factors that has been associated with these conditions. It has been suggested that pollution, noise, disrupted sleep, and social stress could underlie this association.

Diagnosis

Bipolar disorder, schizophrenia, and schizoaffective disorder are each diagnosed based on criteria outlined in the "Diagnostic and Statistical Manual of Disorder of Mental Disorders" (DSM-5), which is the disease classification system used by mental health professionals.

Other potential causes of the symptoms, such as drugs, brain injury, or a major medical illness, such as encephalitis (brain inflammation) must be ruled out for a person to be diagnosed with any of these conditions.

Bipolar Disorder

Bipolar disorder diagnosis requires the presence of at least one manic or hypomanic episode and generally at least one major depressive episode.

Schizophrenia

For a diagnosis of schizophrenia, a person must have symptoms for at least six consecutive months.

Criteria includes at least one or two of the following:

• Delusions
• Hallucinations
• Disorganized speech

If only one of the above is present, a person must also have:

• Severely disorganized behavior
• Negative symptoms, such as catatonic behavior, apathy, lack of expression

For a diagnosis of schizophrenia, the symptoms must be associated with a deterioration in self-care, relationships, or work. 

A diagnosis of schizoaffective disorder requires the presence of symptoms of schizophrenia. The mood symptoms must be present most of the time, but the symptoms of psychosis must be present for more than two weeks without mood symptoms.

Treatment

Bipolar disorder and schizophrenia can be managed with medical interventions, but these conditions are not curable. Counseling is also an important component of the management of these conditions.

Treatments for schizophrenia include antipsychotic medications, which are taken daily to prevent symptoms. Treatments for bipolar disorder include lithium and other mood stabilizers, usually along with antipsychotic medications.

Certain types of psychotherapy can be beneficial in schizophrenia and bipolar disorder.

Treatment with electroconvulsive (ECT) therapy can be beneficial for those with depressive episodes and/or manic episodes in bipolar disorder, and it is considered one of the treatment options for managing the condition.

ECT has been studied as a potential therapy for the treatment of schizophrenia, and it can relieve some symptoms in the short term, but it is not considered a routine treatment for schizophrenia.

Prognosis

Schizophrenia and bipolar disorder are both lifelong conditions, but treatment can improve a person’s prognosis. These conditions can increase the risk of substance abuse and suicide.

Some estimates are that between 4% to 19% of people with bipolar disorder die by suicide, a rate that is 10 to 30 times higher than the general population. A 2020 study found that the suicide rate for people with schizophrenia spectrum disorders is over 20 times higher than for the general population.

These disorders are also associated with a risk of health problems due to neglecting one’s own physical symptoms and a lack of motivation and ability to get medical attention as well as the impact of some of the treatments.

These conditions can worsen acutely, with severe dissociation from reality, thoughts of suicide, and/or self-harm. Episodes of acute worsening may require inpatient hospitalization.

A Word From Verywell

Living with bipolar disorder or schizophrenia is challenging for the person who has the condition, and for their friends and family. Both conditions are characterized by severe distress and relationship difficulties.

The person who is experiencing the symptoms may have a lack of insight, which can interfere with communication, diagnosis, and treatment. However, once a diagnosis is made and treatment is initiated, symptoms can often be well-controlled, with a corresponding improvement in quality of life.

Maintaining a consistent routine, reducing stress, having a healthy diet, and staying active can all contribute to a better overall outcome.