What Causes Hallucinations – An Overview

Estimated reading time: 40 minute(s)

Hallucinations are sensory perceptions that occur without any external stimuli. They can affect anyone, regardless of age, gender, or background, and can be experienced in various forms, such as visual, auditory, olfactory, gustatory, or tactile sensations. Hallucinations are often associated with mental health conditions, such as schizophrenia. They can also occur in individuals with other medical conditions, substance abuse disorders, or as a result of certain medications.

Understanding the causes of hallucinations is crucial for several reasons. It can help in identifying and diagnosing underlying medical or psychiatric conditions. This allows medical professionals to develop appropriate treatment plans for managing hallucinations. Furthermore, it can assist in reducing stigma and promoting empathy in society. 

Therefore, knowing what causes hallucinations and their symptoms is vital to recognize them or getting professional assistance on time.

What Part Of Brain Causes Hallucinations – Understanding the Mechanism

Hallucinations can be associated with various parts of the brain. The same brain regions involved in the condition can vary depending on the underlying cause and type of hallucination. While it is challenging to pinpoint a specific brain region responsible for all kinds of hallucinations, several areas have been implicated in different forms of hallucinatory experiences.

Temporal Lobe

One brain region commonly associated with hallucinations is the temporal lobe. The temporal lobes process sensory information, memory, and emotions. Disturbances or abnormalities in this region have been linked to auditory hallucinations, particularly in individuals with schizophrenia. The auditory cortex, located within the temporal lobe, plays a significant role in the perception of sound and can be overactive or hyperactive in individuals experiencing auditory hallucinations.

Visual Cortex

Another brain area involved in hallucinations is the visual cortex. Visual hallucinations, characterized by seeing things that are not present, can occur due to disruptions in the visual processing areas of the brain. For example, damage or dysfunction in the occipital lobe, which houses the primary visual cortex, can result in visual hallucinations.


The thalamus, a central structure in the brain that acts as a relay station for sensory information, is also thought to play a role in hallucinations. The thalamus helps filter and process sensory inputs, and abnormalities in this region can contribute to hallucinatory experiences. Disruptions in thalamic functioning have been linked to both auditory and visual hallucinations.

Prefrontal Cortex

Moreover, the prefrontal cortex, responsible for executive functions and higher-order cognitive processes, has been implicated in hallucinations. Dysfunction in the region can affect reality monitoring and distinguishing between internal thoughts and external perceptions. Changes in the prefrontal cortex have been observed in individuals with schizophrenia and other psychotic disorders, who often experience hallucinations.

Neural Circuits

Hallucinations are complex phenomena influenced by a network of interconnected brain regions rather than a single isolated area. The brain operates through intricate neural circuits, and disruptions in these circuits can lead to altered perception and the manifestation of hallucinations.

While research has provided valuable insights into the brain regions involved in hallucinations, the precise mechanisms and interplay among these regions are still not fully understood. Further studies utilizing advanced neuroimaging techniques, such as functional magnetic resonance imaging (fMRI) and electroencephalography (EEG), are continually contributing to the understanding of the neural correlates of hallucinations.

What Leads To Hallucinations – Primary Causes

Hallucinations can have various causes, from psychiatric disorders to medical conditions, substances, or medications. Here is a list of some common factors that can contribute to hallucinations:

Psychiatric Disorders: Having psychiatric conditions such as schizophrenia, schizoaffective disorder, bipolar disorder, and other disorders with hallucinations is common. These disorders can disrupt the brain’s perception and processing of sensory information, leading to hallucinations.

Substance Abuse: Hallucinogenic substances like LSD, psilocybin mushrooms, peyote, and MDMA (ecstasy) can induce hallucinations. Additionally, excessive alcohol consumption, cocaine, amphetamines, and cannabis use may contribute to hallucinatory experiences.

Medications: Certain medications, particularly those affecting the central nervous system, can cause hallucinations as a side effect. Examples include antipsychotics, antidepressants, anticonvulsants, antihistamines, and corticosteroids. Withdrawal from certain substances, such as benzodiazepines or opioids, can also trigger hallucinations.

Sleep Deprivation: Prolonged periods without adequate sleep can lead to hallucinations. Sleep deprivation can disrupt the brain’s normal functioning, causing sensory distortions and hallucinatory experiences.

Neurological Conditions: Various neurological disorders can cause hallucinations. Parkinson’s disease, Lewy body dementia, epilepsy, and brain tumors are known to be associated with hallucinatory symptoms.

Sensory Deprivation or Sensory Loss: Individuals who experience prolonged sensory deprivation may develop hallucinations. Additionally, individuals with sensory impairments (e.g., blindness or deafness) may experience hallucinations related to their remaining senses.

Delirium: Hallucinations can occur during episodes of delirium, which is a state of acute confusion often caused by underlying medical conditions, such as severe infections, drug toxicity, metabolic imbalances, or organ failure.

Migraines: Some individuals with migraines may experience visual hallucinations, often called migraine auras. These auras typically manifest as temporary distortions or illusions of vision.

Stress and Trauma: Can stress cause hallucinations? Yes, high-stress levels, traumatic events, or post-traumatic stress disorder (PTSD) can contribute to hallucinations. These experiences may trigger alterations in perception and lead to hallucinatory episodes.

Sensory Processing Disorders: Conditions like synesthesia, where sensory information is processed differently, or Charles Bonnet syndrome, which occurs in visually impaired individuals, can result in hallucinations.

Remember that hallucinations can have multiple factors. People may develop hallucinations due to a combination of contributors.

Causes Of Hallucinations In Elderly – Are Older Age Groups At a Higher Risk Of The Condition?

Hallucinations can occur in individuals of all age groups, but certain factors make hallucinations more prevalent among elderly individuals. While not every older adult will experience hallucinations, the likelihood can increase for various reasons. The following are some factors that contribute to the higher incidence of hallucinations in older people:

Sensory Impairments

Age-related sensory impairments, such as vision and hearing loss, can lead to a higher likelihood of hallucinations. The brain may attempt to compensate for the sensory deficits by creating false perceptions, resulting in hallucinatory experiences.

Cognitive Decline

Age-related cognitive decline, such as mild cognitive impairment or Alzheimer’s disease, can affect the brain’s ability to process sensory information accurately. This can result in misperceptions and hallucinations.

Social Isolation

Elderly individuals may experience social isolation, especially if they live alone or have limited social interactions. Loneliness and isolation can contribute to the development of hallucinations as a way for the brain to cope with sensory deprivation.

Past Trauma

Older adults may have experienced significant life events or traumatic experiences. Trauma can increase the likelihood of hallucinations, particularly in individuals with post-traumatic stress disorder (PTSD).

Lack Of Sleeping

Sleep disturbance, including insomnia or sleep pattern changes, is common in older adults. Sleep deprivation or disruptions can lead to hallucinations, disrupting the brain’s normal sleep-wake cycle.

While the elderly may be more susceptible to hallucinations, these experiences are not normal in aging. If an older adult experiences hallucinations, seeking medical attention for proper evaluation and diagnosis is crucial. Different treatment options can help manage hallucinations and improve the overall quality of life for elderly individuals.

Recognizing Signs Of Hallucinations – Primary Symptoms

Hallucinations can manifest in various ways, depending on the sensory modality affected. The following are the common symptoms associated with different types of conditions:

  • Visual Hallucinations: Visual hallucinations involve perceiving things not present in the external environment. These can range from simple shapes, patterns, or flashes of light to more complex images, people, animals, or objects. The hallucinated visuals may be colorful, vivid, or distorted. They can appear as fleeting glimpses or persistent visions.
  • Auditory Hallucinations: Auditory hallucinations involve hearing sounds or voices that are not real. These hallucinated sounds can range from simple noises, such as buzzing or ringing, to complex voices speaking or conversing. The voices may be perceived as coming from inside the head or as external voices. They can be derogatory, commanding, or benign.
  • Olfactory Hallucinations: Olfactory hallucinations involve perceiving smells or odors that are not present. Individuals experiencing olfactory hallucinations may detect pleasant or unpleasant scents, such as the smell of flowers, burning, or rotting.
  • Gustatory Hallucinations: Gustatory hallucinations involve perceiving tastes without any corresponding stimuli. These hallucinated tastes can be sweet, sour, bitter, or metallic, and they may be fleeting or persistent.
  • Tactile Hallucinations: Tactile hallucinations involve experiencing physical sensations on the skin or within the body without any external cause. These sensations can include crawling or tingling sensations, the feeling of insects crawling on the skin, or the perception of being touched or grabbed by unseen entities.

Hallucinations are typically perceived as real and vivid experiences by the individual, even though they do not correspond to objective reality. They can be distressing, confusing, and disruptive to daily life. Sometimes, individuals may engage in behaviors or conversations with the hallucinations, responding to the perceived stimuli.

Hallucinations can occur in isolation or be accompanied by other symptoms, depending on the underlying cause. For example, individuals with schizophrenia may experience hallucinations alongside delusions (fixed false beliefs) or disorganized thinking. Hallucinations associated with mood disorders, such as bipolar or major depressive disorder, may be accompanied by significant mood or energy level changes.

In addition to the specific sensory experiences, common accompanying symptoms of hallucinations can include:

  • Anxiety or fear related to the hallucinatory experiences.
  • Paranoia or feelings of being watched or controlled.
  • Social withdrawal or isolation due to the distress caused by hallucinations.
  • Depression or mood disturbances.
  • Difficulty concentrating or staying focused.
  • Sleep disturbances or disruptions in the sleep-wake cycle.
  • Impaired functioning in daily activities, including work, relationships, or self-care.

How Are Hallucinations Treated?

The treatment of hallucinations depends on the underlying cause and can vary from person to person. Here are some common approaches used in the management of hallucinations:


Antipsychotic medications are often prescribed for individuals experiencing hallucinations associated with psychotic disorders such as schizophrenia. These medications help reduce the intensity and frequency of hallucinations by targeting neurotransmitter imbalances in the brain. Other drugs, such as antidepressants or anticonvulsants, may be used if hallucinations are associated with mood disorders or epilepsy.


Psychological therapies, such as cognitive-behavioral therapy (CBT) or supportive therapy, can be beneficial in managing hallucinations. CBT helps individuals challenge and modify distressing beliefs or interpretations associated with hallucinations. Supportive therapy provides a safe space for individuals to express their experiences and develop coping strategies.

Environmental and Behavioral Interventions

Creating a supportive environment can help reduce the impact of hallucinations. It may involve minimizing sensory stimuli that trigger hallucinations, such as reducing noise or providing appropriate lighting. Structuring daily routines, engaging in meaningful activities, and maintaining a consistent sleep schedule can also contribute to symptom management.

Addressing Underlying Medical Conditions

If hallucinations are secondary to a medical condition, such as a neurological disorder or substance abuse, treating the underlying cause is crucial. It may involve managing the medical condition through medication, therapy, or lifestyle modifications.

Education and Psychoeducation

Providing individuals and their families with information about hallucinations, their causes, and available treatment options can be empowering. Psychoeducation helps increase understanding, reduces stigma, and promotes self-management skills.

Supportive Services

 Support groups or peer support programs can provide individuals with a platform to connect with others who have experienced or are experiencing hallucinations. These groups offer emotional support, share coping strategies, and give a sense of community.

Treatment plans are usually tailored to the individual’s needs and may involve a combination of approaches. Regular monitoring, medication adjustments, and therapy sessions may be necessary to ensure optimal symptom management and overall health.


Why am I experiencing hallucinations?

Various factors, including psychiatric disorders like schizophrenia or bipolar disorder, certain medical conditions, substance abuse, medications, sleep deprivation, sensory impairments, or high-stress levels, can cause hallucinations. It is essential to consult a healthcare professional for a proper evaluation to determine the underlying cause of your hallucinations.

What is the primary treatment for a mental illness with hallucinations?

The primary treatment for mental illnesses with hallucinations, such as schizophrenia or schizoaffective disorder, often involves a combination of antipsychotic medications and therapy. Antipsychotic drugs help reduce the intensity and frequency of hallucinations, while therapy, such as cognitive-behavioral therapy (CBT), can assist in managing distressing symptoms and developing coping strategies.

What can I do if I start having hallucinations after using a substance?

If you start experiencing hallucinations after using a substance, seek medical help promptly. You can contact a healthcare professional or a local emergency service for immediate assistance. Avoid further substance use, as it may exacerbate the hallucinations. Medical professionals can assess your condition, provide appropriate support, and guide you through detoxification and recovery.

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