Psychosis refers to an altered state of mind, characterized by hallucinations, delusions, and disorganized thinking. Schizophrenia is a disorder in which psychotic symptoms may be present, but they often occur alongside negative and cognitive symptoms, too. Schizophrenia is a disorder, while psychosis is a symptom group.
What Is Psychosis?
Psychosis is not a disorder itself, but rather a category of symptoms that can occur as a result of underlying mental health disorders, medical conditions, or substance use. These symptoms can vary greatly in terms of severity, duration, and content depending on their cause and the individual.
The three main symptoms of psychosis include:
- Hallucinations: A hallucination is a false perception of something without an external cause. These illusory perceptions can form within any sensory modality, including hearing, vision, touch, taste, and smell.
- Delusions: Delusions are distorted beliefs that can not be supported by evidence accessible to others. They can range from clearly implausible to non-bizarre but still highly unlikely.
- Disorganized thinking: Disorganized thinking refers to a problem with how one’s thoughts are organized or communicated. Though disorganized thinking is most easily assessed in speech, it may also be apparent in writing.1 A person with this feature may struggle to maintain a coherent, relevant train of thought while communicating with others.
What is Schizophrenia?
Schizophrenia is a psychotic disorder in which an individual experiences positive, negative, and cognitive symptoms. Positive symptoms refer to the presence of an abnormal feature such as hallucinations and delusions. Conversely, negative symptoms denote the absence of typical experiences, like a lack of motivation or emotional expression. Cognitive deficits (like memory or problem-solving impairments) are not formally required for a diagnosis of schizophrenia, but are commonly present as well.
Schizophrenia is a fairly broad diagnostic category as the specific cluster of symptoms can vary substantially from person to person. While schizophrenia used to be categorized into types (e.g., paranoid type, disorganized type, catatonic type), clinicians and the most recent version of the DSM-5 no longer use these classifications.2
Common symptoms of schizophrenia include:
- Disorganized speech
- Disorganized behavior
- Blunted affect
What Is the Difference Between Psychosis & Schizophrenia?
Psychosis is not a disorder itself, but rather a category of symptoms indicating an altered state of mind. Schizophrenia is a diagnosable condition in which an individual experiences psychosis along with other symptoms, such as flat affect, poverty of speech, or catatonia. While psychosis is a core feature of schizophrenia, psychotic symptoms are common to other mental disorders, medical conditions, and substance use (prescribed or otherwise).
Possible Causes of Schizophrenia & Psychosis
Psychotic symptoms aren’t always indicative of a mental disorder. In fact, they can arise as a adverse effect of prescribed medication, substance misuse, a medical condition, or an infection. While the causes of psychosis can sometimes be determined by the identification of an offending substance or tumor, those of schizophrenia are still not well understood.
Schizophrenia is a disorder with a broad array of symptoms that can manifest as different clusters depending on the individual. Many factors are believed to contribute to its onset, including genetics, neurological dysfunction, substance use, environmental factors, infection, and autoimmune dysfunction. It has even been suggested that schizophrenia can actually be considered a multitude of syndromes, rather than one distinct disorder.3
Possible causes of psychosis include:
- Bipolar disorder: Psychotic symptoms in bipolar disorder are more likely to occur in the context of a manic episode than a depressive episode.
- Depression: As with bipolar disorder and other affective disorders, psychotic symptoms can arise with depressive episodes, particularly during periods of acute symptoms.
- Trauma: Individuals with a history of trauma, particularly repeated sexual trauma, may be more prone to developing psychotic symptoms later on than the general population. Clinicians often notice that individuals with a history of repeated trauma experience psychotic symptoms (usually hallucinations) during periods of fear or times when they may feel unsafe.4
- Neurodegenerative disease: Dysfunction of brain pathways involved with sensation and perception can cause hallucinations. Although not all cases of neurodegenerative disease present with hallucinations, they can occur in a portion of individuals with dementia, Parkinson disease, Alzheimer disease, and Huntington disease.5
- Medical conditions: Other medical conditions that can cause hallucinations include epilepsy, brain tumors, traumatic brain injury, thyroid dysfunction, Hashimoto encephalopathy, chromosomal disorders, and autoimmune disorders.6, 7, 8, 9, 10, 11
- Sensory disorders: Although many sensory disorders do not result in hallucinatory experiences, they have been reported in cases with hearing impairment, eye disease, deafness, and tinnitus.12, 13, 14
- Sleep-related conditions: Research suggests that sleep deprivation/lack of sleep, sleep paralysis, and narcolepsy can produce hallucinatory experiences.15
- Substance use: Many substances (e.g., cannabis, stimulants, psychedelics, cathinones) can induce a psychomimetic (i.e., “mimicking psychosis”) response. Symptoms often subside as the substance is eliminated, but when they persist, it may be identified as drug-induced psychosis.
- Substance use disorder: Chronic substance use or misuse can result in longer-lasting impairment to brain pathways (especially in adolescents), increasing the risk of psychosis and other complications. Though the causal link is not clear, up to 50% of individuals with schizophrenia also share a substance use disorder that often precedes the onset of schizophrenia.16
- Prescribed medications: Certain prescribed medications can have psychotic side effects, such as antidepressants, muscle relaxants, stimulants, and even certain antivirals and antibiotics17, 18, 19, 20, 21, 22.
- Toxins: Certain elements in one’s environment, such as lead, gasoline, glues, paint thinners, and anticholinesterase, have been shown to cause psychotic symptoms, although the prevalence of toxin-induced psychosis is not clear.2, 23, 24, 25
- Physical and psychological stress: Stress can trigger physiological changes in the brain and body. Although fairly rare, extreme cases of psychological stress incurred by sensory deprivation, fatigue, bereavement, or abuse can lead to hallucinations.4, 26
- Vitamin deficiencies: Although the research is mixed, it has been suggested that Vitamin B12 and D deficiencies may be related to one’s susceptibility to experiencing hallucinations.29, 30
Possible causes of schizophrenia include:
- Brain structure: The symptoms of schizophrenia are broad and likely stem from dysfunction in various parts of the brain, such as the prefrontal cortex, limbic system, and striatum, are of particular interest to researchers trying to understand this disorder.
- Neurotransmitters: The dopamine circuit seems to play a significant role in many psychotic symptoms. Other neurotransmitters, like GABA, glutamate, and serotonin (5-HT), also seem to work in concert with dopamine, as neurotransmitters regulate one another in the complex brain system.
- Genetics: Schizophrenia is believed to have a genetic component, as having a first degree relative with the disorder increases the risk for development.30 However, a single gene has not been identified as the main cause.
- Severe stress: Numerous factors can impose immense stress on an individual, which can either lead to the gradual development of schizophrenia or trigger its sudden onset.
- Substance use: Drugs of abuse are thought to increase vulnerability to schizophrenia, especially substances affecting dopamine, like amphetamines, cocaine, and cannabis.
- Autoimmune and inflammation: Individuals with certain autoimmune diseases are two to five times more likely to develop schizophrenia.4 Along with these and a pro-inflammatory diet, neuroinflammation may be a potential cause or correlate of schizophrenia symptoms.31
- Infection: Research suggests that prenatal exposure to certain viral or parasitic infections increases the risk of developing schizophrenia later in life.4
How Are Psychosis & Schizophrenia Diagnosed?
Given that psychosis is a symptom of schizophrenia, the diagnostic testing typically involves much of the same process, whether schizophrenia or another cause is suspected. Depending on the severity of the individual’s active symptoms, an evaluation could take place in an outpatient mental health clinic or hospital emergency room. It may include a physical exam, psychiatric evaluation, neuropsychological testing, blood, and urine tests.
People with psychotic symptoms may not be aware that they are experiencing a hallucination or delusion, and thus having a family member accompany the individual to the evaluation can be helpful. As there can be several causes of psychotic symptoms, a doctor will likely ask the person questions about their recent activity and how they are experiencing the symptoms. They may also gather family history, order toxicology screens, and work towards stabilizing the individual.
While some causes of psychotic symptoms may be clearly revealed by medical tests (e.g., drug use and brain tumor), mental health disorders—like bipolar disorder or schizophrenia—take more time to diagnose and will likely involve a battery of cognitive and neuropsychological tests, as well as some personality and projective tests.
There are often signs or mild symptoms that precede the full psychotic expression of schizophrenia, and this initial period is referred to as the prodromal phase. Recognizing these early signs can improve the prognosis and secondary problems that schizophrenia can cause. Positive symptoms of schizophrenia tend to be more noticeable to others than negative symptoms. Thus, they often provide the impetus for family and friends to seek help or support for the individual.
The DSM-5 criteria for diagnosing schizophrenia include:
- The presence of at least two symptoms of schizophrenia must be present, with at least one being a positive symptom.
- Negative symptoms can be among the symptoms to meet criteria, as long as a positive symptom is present.
- Key symptoms must last for a period of at least one month. The condition’s effects must also last for at least six months.
- Social or occupational dysfunction must also be present during the period of dysfunction.
Can You Have Psychosis Without Schizophrenia?
Psychosis can occur in the absence of schizophrenia, potentially due to substance use, medication adverse effects, and other medical and mental health conditions. Schizophrenia has a prevalence of less than 1% of the global population, while psychotic experiences occur in approximately 4-7% of people worldwide.4, 32, 33 In fact, 80% of these cases are transient. Prevalence of such experiences is higher in older adults and children, although they can occur during all phases of life and for many reasons.34
The fine line between isolated psychotic-like experiences and clinical psychosis can be drawn where the hallucinations or delusions intrude on activities of daily living.
Do People With Schizophrenia Always Have Psychosis?
Psychotic symptoms are hallmark to schizophrenia, but are not always present together. Diagnostically, the DSM-5 criteria for schizophrenia require that at least one positive symptom must be present for a significant portion of time. In that sense, psychosis can be considered a necessary aspect to diagnose the disorder. Though once diagnosed, psychotic symptoms may wax and wane with treatment.
The onset of schizophrenia (especially in children and adolescents) is often insidious, rather than acute, with the illness typically developing for many months before the first psychotic symptoms manifest. This prodromal phase of schizophrenia is a period that can last up to 24 months before an individual meets full criteria for the illness.
How Are Psychosis & Schizophrenia Treated?
Psychotic symptoms can feel frightening, for both the person experiencing them and their loved ones. These symptoms can also give rise to dangerous behaviors. If someone you care about is at risk for harming themself or others, call 911 or go to the nearest emergency room.
The main purpose of hospitalization is to stabilize the individual and the duration will vary depending on the cause and responsiveness to acute treatment, but may last days to a couple of weeks. Once stabilized, outpatient resources such as therapy, skills training, and other services can be provided to support the individual moving forward.
Treatment for psychotic symptoms will vary depending on the cause. For substance-induced psychoses, detoxification and time may bring stabilization. However, when a dependency is involved, a treatment program will likely be recommended. Psychotic symptoms brought on by a medical condition can abate with medical treatment for that specific problem.
Psychotic symptoms may be treated with:
- Elimination of offending substance
- Treatment of medical condition (e.g., removal of tumor)
- Antipsychotic medication
- Individual therapy
- Group therapy
- Stress reduction
- Improvement in sleep hygiene
- 12-Step programs
Pharmaceutical treatment is often the first and most effective means of alleviating psychotic symptoms, assuming the underlying cause is not situational or related to an external agent. An effective treatment plan for schizophrenia usually involves therapy and social skills training in conjunction with medication. It is important to not just treat the acute symptoms, but also establish access to support resources to help the person navigate the ups and downs of this chronic disorder.
Schizophrenia is typically treated utilizing a combination of:
- Typical antipsychotics: First-generation or typical antipsychotics work by reducing dopamine levels. Antipsychotics are considered first-line in the treatment of schizophrenia.
- Atypical antipsychotics: Second-generation or atypical antipsychotics work differently than typical antipsychotics by modulating both serotonin and dopamine. However, their efficacy above typical antipsychotics remains to be elucidated.34
- Injectables: Longer-acting antipsychotics can be injected by medical professionals to avoid reliance on regular daily medication adherence.4
- Behavior therapy (BT): BT can offer patients concrete rewards for improving behaviors that can be problematic among those with psychosis.
- Cognitive behavioral therapy (CBT): CBT can help individuals learn to perform reality testing on their hallucinations and delusions.
- Family therapy: Family therapy can help family members create an environment of support and positivity that reduces anxiety. This can help prevent certain symptoms before they arise.
- Group therapy: Realizing that you are not alone in your experiences can help you become more comfortable dealing with psychotic symptoms.
- Psychodynamic therapy: Psychodynamic therapy can sometimes help patients recognize how their psychotic symptoms may be related to past traumas.
- Social skills training (SST): SST can be particularly useful to help an individual develop skills that are often deficient when experiencing psychosis.35
- Cannabidiol (CBD)*: Some research suggests that the CBD may be used as a relatively safe and tolerable therapeutic to treat schizophrenia symptoms.35, 36
- Alternative treatments: While antipsychotic medication is a main treatment strategy, alternative treatments for schizophrenia such as yoga therapy, nutritional adjustments and vitamin supplements can be beneficial as complementary, add-on treatments.
*Please note that most CBD on the market is not regulated and many products have been found to have inaccurate dose information. Furthermore, CBD does have side effects as well and can interact with other medications. It is always recommended to consult with your doctor before using.
When to Seek Professional Support
Early intervention is key to slowing the progression of psychosis and maintaining social connectedness, as isolation can lead to a vicious cycle that can exacerbate symptoms. Psychotic symptoms may also be an indicator of another condition that can benefit from immediate attention. Your primary care physician may be a good place to start, but if an in-person visit to a doctor is not viable, there are online psychiatrist options and online therapy options available.
If you or someone you care about is experiencing psychotic symptoms, seeing a doctor is strongly encouraged to help determine the cause and receive treatment and support. Though some people experience individual symptoms associated with schizophrenia, it is important to remember that schizophrenia itself is a rare mental illness. Psychotic symptoms can be unnerving, but recognizing that they may not be permanent—along with understanding why they’re occurring and having supportive resources in place—can make a huge difference in your life.
For Further Reading
- The Essential Schizophrenia Companion / Robert Francis
- Are There Different Types of Schizophrenia?
- How to Get Help for a Friend or Loved One
- 21 Best Mental Health Podcasts
- Substance Abuse and Mental Health Services Administration (SAMHSA)
- NIDA Treatment Resources
- Double Trouble in Recovery (dual diagnosis)
- SMART Recovery (non-faith-based addiction recovery)
- Alcoholics Anonymous
- Cannabis (Marijuana) Research Report / NIH
- Marijuana and Public Health / CDC