Is Paranoia A Mental Illness? Causes And Risk Factors

Paranoia generally describes a false belief or suspicion that others are plotting against you or intend to cause you harm. Many people wonder, is paranoia a mental illness? While it’s often associated with mental health disorders, paranoia is not usually viewed as a mental illness in and of itself. In fact, up to 20% of the general public is thought to experience paranoia symptoms. 

Paranoia can be a symptom of various personality disorders, psychotic disorders, and other mental health conditions, like depression and anxiety. Dementia, traumatic brain injury, sleep deprivation, and substance use may also contribute to paranoia. If you’re experiencing paranoid thoughts that are impacting your mental well-being, consider reaching out to a licensed therapist for support.

Personality disorders

Paranoia may play a part in multiple personality disorders, but it tends to be most common among two. Both paranoid personality disorder and borderline personality disorder have paranoia listed as a symptom in their diagnostic criteria.

Paranoid personality disorder (PPD)

Up to 4.4% of people have paranoid personality disorder (PPD), and it may be the second most common personality disorder. 

People with paranoid personality disorder tend to be overly suspicious that others are out to get them or cause them harm. When a person believes these paranoid thoughts, it can limit their ability to function socially and negatively affect their everyday life. 

Many people with PPD experienced childhood trauma in the form of abuse, neglect, or sexual molestation, which may have affected their ability to trust others.

The severity of paranoia, as well as how a person responds to paranoid thoughts, may determine how much PPD affects a person's life. Many people can live fulfilling, enjoyable lives despite mental illness. However, some people with PPD are overcome by paranoia that leads to physical aggression, unnecessary lawsuits, or other behaviors that cause distress and make it difficult to maintain healthy relationships.

About 75% of people with PPD also have another personality disorder. The most common comorbid mental disorders among people with PPD are usually avoidant personality disorder and borderline personality disorder. 

Borderline personality disorder (BPD)

Up to 2.7% of the general population has borderline personality disorder (BPD). People with BPD may experience extreme mood swings, an unstable self-image, and frequent interpersonal relationship problems, all of which generally stem from a deep-seated fear of abandonment. Like people with paranoid personality disorder, those with BPD often have a history of childhood abuse or neglect. 

Paranoia can be a symptom of BPD. Unlike with paranoid personality disorder, in which paranoia tends to be constant, people with borderline personality disorder may have temporary bouts of paranoia. These short-term paranoia experiences tend to arise in response to stressful situations and typically pass once the stress has been relieved. Paranoia among people with BPD can relate to relationship problems or the fear of abandonment. For example, a person may incorrectly suspect that a loved one plans on ending their relationship.

Psychotic disorders

Paranoia is often considered to be a type of delusion. Delusions can be defined as false beliefs that a person persistently holds, despite them not being grounded in reality. Paranoid delusions may be described as false beliefs that involve sensing others are out to get you. Delusions of all types can greatly affect a person's overall mental health and ability to function in the world.

All psychotic disorders have delusions as potential symptoms, so paranoia may accompany any psychotic disorder. That said, two psychotic disorders often involve paranoia: schizophrenia and delusional disorder.

Schizophrenia

Around 1% of people have schizophrenia. In addition to delusional beliefs, people with schizophrenia often have hallucinations that involve seeing, hearing, smelling, or feeling things that aren't actually there. They may also experience disorganized thoughts and speech, as well as a lack of expected emotional expression. Schizophrenia often develops during young adulthood, and it's thought to result from a combination of genetics and environmental factors.

Schizophrenia is often viewed as one of the most impactful psychiatric disorders, and it is one of the top 10 causes of disability worldwide. Paranoia experienced in schizophrenia may involve bizarre or highly implausible beliefs, such as the belief that government agents have found a way to read a person's mind.

Delusional disorder

Delusional disorder is considered rare, only occurring in up to 0.1% of people. People with delusional disorder typically hold delusions for at least a month, and some of these delusions may be paranoid in nature. Those who have paranoid delusions are generally considered to have the "persecutory type" of the disorder, as they frequently believe people are persecuting them, conspiring against them, or planning an attack or harassment.

Compared to those with schizophrenia, people with delusional disorder generally have a more stable life and symptoms that appear at an older age. Their delusions are often less bizarre than those seen among people with schizophrenia. 

These delusions tend to be plausible and normally pertain to people the person with delusional disorder actually knows. For example, instead of believing that government agents are reading their mind, a person with delusional disorder may believe their next-door neighbor is planning to sue them or their boss is planning to fire them. 

Other mental health disorders

While personality and psychotic disorders are the disorders most often characterized by paranoia, the symptom can appear among people with other mental health disorders, too. 

Anxiety disorders

Although not one and the same, anxiety and paranoia may overlap. A systematic review looked at 19 experimental studies and found that anxiety may have a cause-and-effect relationship with paranoia. 

More research is needed to know for sure, but studies indicate that a therapy treatment focused on reducing anxiety could also lead to reduced paranoid thoughts.

One study found that people with high levels of paranoia usually also had high anxiety, but those with high anxiety didn't necessarily experience more paranoia, conflicting with other research results. The relationship between anxiety and paranoia appears to be complex. Anxiety or stress may result from paranoia in some cases. 

In addition, anxiety or stress may trigger paranoia, but possibly only in people who are predisposed to it. Future research will likely clarify the relationship between these two often distressing symptoms.

Depression

Research shows that having depression can make a person more likely to have paranoid thoughts. That said, experts aren't sure exactly why depression and paranoia seem to be linked. The connection could be due to other factors often present among both concerns, such as childhood abuse, anxiety, or insomnia. Depression often involves trouble sleeping. 

Other research has found that both depression and insomnia can be linked to increased paranoia. Some researchers have found evidence that depression could result in more paranoia due to negative cognition, although updated research may be needed. They define negative cognition as low self-esteem, self-criticism, and severely negative beliefs about oneself and others. As with anxiety, more research is needed to fully clarify the various factors impacting the relationship between depression and paranoia.

Physical health disorders

Paranoia often arises after individuals have developed an illness or experienced an injury impacting the brain.

Dementia

After developing dementia, a person may have paranoid delusions. For example, people with Alzheimer's disease may develop symptoms of psychosis, which can involve paranoia. 

One case study described a man who had dementia with Lewy bodies and began to believe there were people outside of his house who wanted to kill him. Alzheimer's disease and dementia with Lewy bodies appear to be the two most common types of dementia.

Some experts have argued that paranoia may become more common with age, whether a person develops dementia or not. While there are many anecdotal reports of paranoia among aging adults, research has found that a younger age can be a risk factor for developing paranoia. More research is needed to confirm the relationship between paranoia and age.

Traumatic brain injury (TBI)

People who experience traumatic brain injury (TBI) may face an increased risk of mental illness afterward. While depression tends to be the most common psychiatric illness to develop after TBI, psychotic symptoms sometimes occur. Paranoia may be one of the most common psychotic symptoms among people who have experienced TBI. 

After TBI, a person may believe they are being persecuted or others are out to get them. Some experts believe this may be an adaptive evolutionary response. They propose that experiencing TBI could make a person more vulnerable to being taken advantage of, and becoming more suspicious for a time could potentially protect against that. However, many people who have paranoia after TBI find that it hurts them rather than helps.

Other brain disorders

In addition to dementia and traumatic brain injury, paranoia may develop in conjunction with other brain disorders. For example, experts report that paranoia can be found among people with epilepsy (a seizure disorder) and those with certain types of brain tumors.

Substance use

In some cases, a person has an underlying disorder or propensity for a disorder, like schizophrenia or generalized anxiety disorder, and substance use can trigger or worsen their paranoia symptoms. In other cases, a person may have no mental health disorder and experience paranoia on its own in response to substance use. Discontinuing the substance use can be key to reducing or reversing paranoia in these cases.

Sleep deprivation

When people go more than two days without sleeping, they may be likely to experience psychotic symptoms, which may include paranoia. In this instance, paranoia may involve extremely bizarre scenarios. For example, one study participant believed he was responsible for an international war and that a secret agent was trying to contact him and convince him to travel to the area. Another believed that other study participants were plotting to kill him. Paranoia that develops during sleep deprivation generally dissipates after the sleep deprivation ends.

In addition to total sleep deprivation, insomnia appears to increase paranoia, albeit not always to the same extreme. As a result, successfully treating insomnia can reduce a person's paranoid thoughts.

When to seek treatment for paranoid thoughts

If paranoid thoughts are causing you distress or limiting your life, you may want to seek treatment. You do not need to have a diagnosed mental illness to have paranoid thoughts or benefit from talk therapy. People with paranoia may find remote therapy particularly convenient. Remote therapy generally allows you to attend therapy sessions from the comfort of your own home or any preferred location. BetterHelp is a platform that can connect you with a remote therapist skilled in helping people with similar challenges.

If you have both anxiety and paranoia, receiving therapy geared toward anxiety may be useful. A 2019 study with participants experiencing paranoid thoughts found that anxiety-based cognitive behavioral therapy (CBT) usually reduced paranoia compared to a control group. 

Research suggests that online CBT tends to be just as effective as in-person CBT, supporting the use of internet-based CBT for paranoia.