What is a Hallucination?
You may be having encountered this word in a Science class when studying substance abuse. Is the just as it was defined in Primary School? Let us have a deeper look into this word, what causes it and its treatment among other issues concerning the same. A hallucination is the experience of seeing, hearing, tasting, smelling or feeling something that is not really there because you are ill or have taken a drug. It can also be defined as a perception experienced in the absence of an external stimulus to the corresponding sense organ. Unlike dreaming, illusion and imagery, a hallucination is perceived to exist in the external objective space. It occurs when one is awake. And even though a hallucination may appear to be real, it is just a creation of the mind. A substance such as a drug that causes one to hallucinate is called a hallucinogen. There are different types of hallucinations which include the following:
- Visual hallucinations
- Auditory hallucinations
- Olfactory hallucinations
- Tactile hallucinations
- Gustatory hallucinations
But today we focus on one type – visual hallucinations. We are going to look at the causes and treatment of visual hallucinations.
What are Visual Hallucinations?
Visual hallucinations are hallucinations that involve the eyes, where one sees things that are not really there. Patients suffering from visual hallucinations often see things which are not seen by the people around them, not because these people have eye problems, but because those things are not really there, as they are created in and by the mind of the patient. Therefore, those things are and can only be seen by the patients experiencing visual hallucinations. Visual hallucinations can be divided into simple visual hallucinations and complex visual hallucinations. The former refers to indiscreet objects, colors, lights and geometric shapes, while that latter refers to clear images such as cars, trains, people, animals and trees. For example, a simple visual hallucination of a house may only look like a house to the one hallucinating, but a complex visual hallucination of the same would be very clear in the eyes of the patient.
Visual hallucination can be scary to both the ones suffering from it and those with them. For example a person could hallucinate seeing a vehicle almost running over people and warn them aloud. This would be scary to both the parties.
Symptoms of Visual Hallucinations
- Speaking about things that are not actually there
- Reduced sense of judgment
- Awkward behavior e.g. chasing someone who is not really there
- Getting scared in the case of perceiving scary images, animals or people
- Confusion and memory lapses
Why Do We Hallucinate?
Visual hallucinations have several causes, most of which are illnesses-related. The causes are discussed below.
- Certain drugs can be responsible for hallucinations. These kinds of drugs are known as hallucinogens as indicated earlier. They alter the perception of an individual. A few examples of such drugs are Mescaline, Psilocybin, and Lysergic Acid Diethylamide (LSD). They will not produce true hallucinations unless they are used in high doses. Atropine and dopamine agonists are also considered to be hallucinogens.
- Withdrawal from substance abuse – Substances like Cocaine, Marijuana, Heroin, and LSD (a synthetic crystalline compound, Lysergic acid Diethylamide that is a potent hallucinogenic drug) can cause visual hallucinations. During withdrawal from these substances, someone can experience visual hallucinations.
- Alcohol. People who are intensely intoxicated and those withdrawing from long-term alcoholism, or addiction to alcoholism can experience hallucinations.
- Psychiatric illnesses – some of these are Schizophrenia, delirium and dementia.
- High fever – this applies to children with high fevers but resolve quickly as the fever responds to treatment.
- Those with sensory problems like blindness may have visual hallucinations.
- Severe depressive disorder. Patients suffering from depression psychosis experience hallucinations.
- Seizures. These hallucinations usually consist of small dots or flashes of light. Their sizes may be distorted or suddenly change shape or may move from position to another position.
Conditions that May Present with Visual Hallucinations
Several conditions may present with visual hallucinations, and they are briefly discussed below:
Delirium, also known as an acute confused state, is a serious disturbance in the mentality that results in confusion and reduced awareness of the surroundings. Delirium is an acute condition that often starts very rapidly in just a few hours or days. It can be caused by withdrawal from alcohol, substance abuse, metabolic disturbances, and infections or as a result of certain drugs. Visual hallucinations are the most common type of hallucinations among patients with delirium.
Delirium from alcohol withdrawal, known as delirium tremens, and delirium from substance intoxication is commonly accompanied by visual hallucinations.
- Psychosis – Schizophrenia and Schizoaffective disorder.
Hallucinations are listed as a primary diagnostic criterion for the diagnosis of various psychotic diseases. Even though auditory hallucinations are the most common presentation in most psychotic illnesses, other hallucinations like visual, gustatory, olfactory and tactile hallucinations could also occur. About 16% to 27% of patients with schizophrenia and schizo-affective disorder have been reported to have visual hallucinations.
- Sleep disturbances
There are two types of visual hallucinations that can occur during sleep. They are known as hypnagogic or hypnopompic hallucinations. Hypnagogic hallucinations usually occur when a person is falling asleep, while hypnopompic hallucinations occur when waking up from sleep. These hallucinations are usually brief and simple. It is common for a healthy individual with no psychiatric illness to develop such hallucinations. Usually the person wakes up from sleep suddenly and they will realize the nature of their experience.
Tumors that may compress the optic pathway may also give rise to visual hallucinations. The content of their hallucinations are often complex and see vivid scenes like people carrying out mundane tasks. Most of these visual hallucinations are thought to be due to the seizure activities caused by the tumor itself.
Migraine is another common condition where a person may experience visual hallucinations in the form flashing lights. These experiences are usually considered as an aura of the migraine attack and are often helpful in its diagnosis.
Treatment of Visual Hallucinations
The treatment of visual hallucinations depends on its underlying cause. Therefore, it is of vital importance that an accurate diagnosis is made before the commencement of the treatment. This is because the treatment for one cause of visual hallucinations may exacerbate another cause of visual hallucinations.
Neuroleptic medications are the drugs of choice in the treatment of visual hallucinations. It is effective in treating delirium tremens as well. The most safe as well as the most effectively used drug is haloperidol.
Unfortunately, due to the side effects of neuroleptic drugs that may produce Parkinsons-like symptoms, they cannot be used with dementia patients associated with Parkinson’s disease. For these patients, Quetiapine and Clozapine are the best options.
If the visual hallucinations are due to seizures, then these patients should be treated with anti-epileptic drugs. If the hallucinations are due to a tumor, then surgery and radiation will help to reduce them and if they are due to migraine, then triptans or beta blockers should be prescribed. So, likewise, the treatment of visual hallucinations will depend on its underlying cause and their treatments will vary according to the underlying cause.
Reassurance by the care givers and Psychotherapeutic interventions such as cognitive behavioral therapy will benefit all patients regardless of their drug treatment. Psychotherapeutic interventions help to reduce visual hallucinations by improving their insight about the disease.