Learn What Causes Paranoia In Adults

Symptoms of paranoia can be difficult to face, whether you are experiencing it yourself or are close to someone with paranoid thoughts. When a person experiences paranoid thinking, they usually believe someone is trying to cause them harm, even when reality doesn't reflect that belief. Paranoia can range from mild to severe. When severe, paranoia can greatly disrupt a person's relationships and limit their life, as they may make false accusations and isolate themselves out of fear.

Anyone who has experienced or witnessed paranoia may naturally be curious about what causes it, but experts haven't yet identified a single exact cause. Instead, there appears to be a range of risk factors and potential explanations for paranoia, ranging from substance misuse to personality disorders. In addition, different people may have paranoid thoughts for different reasons. Read on to learn possibilities for what causes paranoia in adults, and consider reaching out to a licensed therapist if paranoia affects your daily life or mental health.

Mental illness

When a person has paranoia, mental illness is often the first explanation that comes to mind. Mental health conditions commonly associated with paranoia include paranoid personality disorder, schizophrenia, delusional disorder, and borderline personality disorder. We will go into more detail on each below. 

However, to a lesser extent, paranoia has also been tied to other mental illnesses, such as anxiety disorders, schizotypal personality disorder, bipolar disorder, and major depressive disorder.

Paranoid personality disorder

Paranoid personality disorder (PPD) is present in approximately 1.2% to 4.4% of people. PPD is a mental illness in which a person usually has personality traits of excessive distrust and suspicion that disrupts their daily functioning. People with PPD may become overly angry about others' wrongdoings and assume the worst about people's motives. They may seem overly self-important and tend to ruminate on perceived slights, often complaining that they've been treated unfairly or are oppressed. PPD can lead people to become hostile to those in their lives and even become aggressive or engage in stalking. In some cases, PPD is associated with excessive lawsuits against others.

While people with PPD have paranoia, they usually do not have the delusions or hallucinations that are typically associated with psychotic disorders. Instead, they are generally distrustful of people with whom they interact and upset about things that have actually happened, although their responses may seem overblown to many. In contrast, people with delusional paranoia are usually suspicious about scenarios that have little to no grounding in reality, such as believing the government has tapped their phones or sent people to follow them around.

Some experts believe PPD is understudied, which can make it difficult for mental health professionals to understand people who have the disorder and makes it difficult to treat it. There are currently no FDA approved medications for PPD. 

Schizophrenia

Schizophrenia generally involves positive symptoms like delusions and hallucinations, as well as negative symptoms like a lack of motivation and emotional expression. Delusions can be described as untrue beliefs that don't match up to reality, while hallucinations typically involve seeing, hearing, smelling, tasting, or feeling sensations that don't correspond with reality. 

Paranoid delusions tend to be the most common type of delusion among people with schizophrenia. Among people with schizophrenia, those with paranoia tend to be likely to interpret social situations differently and misinterpret neutral facial expressions as being angry. People with paranoia may be less likely to trust others, could act with more hostility, and may unfairly blame others for things. Those with paranoia may have worse outcomes than those who have schizophrenia without paranoia, but existing studies have returned mixed results, so more research may be needed to confirm this.

It should be noted that while the phrase "paranoid schizophrenia" may be commonly used by lay people, it is considered an outdated term and is no longer an official diagnosis in the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition, DSM-V-TR).

Paranoia experienced with schizophrenia may be severe or involve highly delusional beliefs. For instance, examples of schizophrenia-related paranoia given by the Substance Abuse and Mental Health Services Administration (SAMHSA) include a person believing that someone else can control their mind or is going to physically harm them. 

Delusional disorder

Delusional disorder is a relatively rare disorder that normally involves believing in one or more delusions for over a month. A person with delusional disorder may incorrectly believe their romantic partner is cheating, that a person of high status is secretly in love with them, that they have great talent or intelligence, or that they are being conspired against or attacked, among other potential delusions.

People who believe others are conspiring against them are usually most likely to be paranoid. They may also be easily irritated, anxious, and, at times, aggressive. In some cases, people with delusional disorder who believe someone is out to get them may engage in assault or bring lawsuits against others.

Borderline personality disorder

Borderline personality disorder (BPD) is a personality disorder typically characterized by a strong fear of abandonment that can lead to poor self-image, mood swings, impulsiveness, and rocky relationships. One symptom of BPD is temporary paranoid thinking related to stress.

When a person with BPD experiences paranoia, it doesn't usually last very long. This can differ quite a bit from the paranoia seen in paranoid personality disorder, schizophrenia, and delusional disorder. A person with BPD may become paranoid temporarily, particularly while they are experiencing a conflict with someone. Their paranoid thoughts may involve their fear of abandonment. For example, they may wrongly assume a romantic partner is planning to leave them, or friends who spent time together without them are plotting something against them.

Childhood trauma

All of the previously mentioned mental illnesses involving paranoia may be more likely to develop among people who experienced childhood trauma. Some experts propose that paranoia can develop in response to experiencing emotional neglect or other types of poor treatment in childhood. 

Paranoia often involves incorrectly thinking others are treating oneself unfairly or intentionally trying to cause harm. When a person is experiencing paranoia, those thoughts are usually disconnected from reality. However, they may have once been true in a person's life if they grew up with abuse, neglect, or other forms of trauma or injustice. While being paranoid and questioning people's motives might not currently benefit a person, it could have been an adaptive strategy or reasonable response at a different point in their life.

People with traumatic childhoods may also be more likely to experience paranoia due to the changes trauma can cause in the brain. Childhood trauma tends to be associated with a variety of changes to the brain’s structure, which can also be linked to mental health symptoms like paranoia.

Chronic stress

Research suggests that having experienced a higher number of stressful events over the past year can increase the likelihood that a person will have paranoia. Chronic stress can make paranoid personality disorder and other mental illnesses more likely to develop or worsen symptoms in those who have a mental illness with symptoms of paranoia.

Some experts believe that paranoia could serve an evolutionary purpose. According to this view, becoming more suspicious of others after experiencing danger or a threat could serve to protect a person and help them become aware of and avoid future threats or danger. This could explain why trauma and stress may trigger or increase paranoia. That said, if paranoia does serve an evolutionary purpose, that doesn't necessarily mean it is currently useful for most people. Experiencing paranoia may be seen as experiencing an age-old protective response that has become less helpful or even harmful in the current day and age.

Substance use

Paranoia tends to be one of the most common side effects of recreational substances. A variety of substances have been linked to paranoia symptoms, including the following:

• Alcohol
• Cannabis
• Cocaine
• LSD
• Methamphetamine

In people already prone to psychosis, including paranoia, caffeine consumption may worsen symptoms.

Health problems

Certain physical health problems have been linked to the development of paranoia.

Dementia and brain disorders

Paranoia may occur after epileptic seizures or a traumatic brain injury. In fact, up to 26% of people who have had a brain injury meet paranoid personality disorder diagnostic criteria. Similarly, paranoia can also accompany brain tumors or dementia. Usually, in these situations, paranoia is not the sole symptom, but on rare occasions, it could be.

People familiar with Alzheimer's disease and other forms of dementia may have already heard of dementia-associated paranoia. When a person with dementia or another type of brain disorder develops paranoia, they often become suspicious of loved ones or caregivers, wrongly accusing them of theft or an intention to cause harm. They may also become easily irritated, agitated, anxious, and prone to act aggressively, in part because of these false, paranoid beliefs.

Sleep deprivation

Severe sleep deprivation can lead to symptoms of psychosis, including paranoia. Often, more severe paranoia and delusion symptoms develop after a person has been awake for over 24 hours. After going two or three days without sleep, almost everyone will develop some sort of delusions or hallucinations, and they may involve paranoia. Paranoid delusions could be severe and intense, such as being convinced that someone nearby is about to inflict violence upon oneself.

Paranoia may also occur among people who are still sleeping every night, but not getting enough sleep. Although updated research may be needed, one study found that among people with high levels of paranoia, over half had moderate or severe insomnia. 

More research may be needed to understand the link between paranoia and a lack of sleep. While falling short on sleep can increase paranoia, it seems that experiencing paranoia can also worsen sleep.

Genetics

Genetics can play a role in mental illnesses involving symptoms of paranoia. For example, specific genes appear to have a link to schizophrenia. However, experts stress that genetics alone do not determine whether a person will develop a mental illness involving paranoia. Many other factors, including childhood experiences, social relationships, stress levels, overall health, and more, can also play a role.

Some research has also looked at genes and the experience of paranoia in the general population. These studies have found a link between the tendency to have paranoid thoughts after experiencing stress and the presence of certain genes. While updated evidence may be necessary, this research illustrates how a person may need both certain genes and certain environmental experiences to develop a symptom like paranoia.

When to see a mental health professional

The organization Mental Health America (MHA) says paranoia is generally treated with medication and/or cognitive behavioral therapy. Speaking with a licensed mental health professional is very important if you are having paranoid thoughts.

Remote therapy is one option for people experiencing paranoia, whether as part of a mental illness or as a lone symptom. With virtual therapy, a person can attend sessions without having to go out in public, which some people with paranoia may appreciate. BetterHelp is a remote therapy platform that can match you with a mental health professional well-suited to meet your needs.

Treatments specifically for paranoia haven't been widely studied. However, paranoia is a symptom that can be involved in psychosis, which has been studied more extensively. Medications are often used to treat paranoia related to psychosis. Cognitive behavioral therapy (CBT) can reduce symptoms of psychosis, such as delusions and paranoia. One way CBT may help is by teaching people to slow down their thinking and evaluate the likelihood that their assumptions are true before drawing conclusions.

Always consult with a medical professional before starting, stopping or changing any medications. 

Research suggests that online CBT tends to be just as effective as in-person CBT, which may mean that online cognitive behavioral therapy could be an effective form of treatment for paranoia. However, those experiencing active psychosis may require in-person care.