Narcissistic personality disorder is rarely the primary reason for people seeking mental health treatment. When people with NPD enter treatment, it is typically prompted by life difficulties or to seek relief from another disorder, such as major depressive disorder, substance use disorders, bipolar disorder, or eating disorders, or at the insistence of relatives and friends. This is partly because individuals with NPD generally have poor insight and fail to recognize their perception and behavior as inappropriate and problematic due to their very positive self-image.

Treatment for NPD is centered around psychotherapy. In the 1960s, Heinz Kohut and Otto Kernberg challenged the conventional wisdom of the time by outlining clinical strategies for using psychoanalytic psychotherapy with clients with NPD that they claimed were effective in treating the disorder. Contemporary treatment modalities commonly involve transference-focused, metacognitive, and schema-focused therapies. Some improvement might be observed through the treatment of symptoms related to comorbid disorders with psychopharmaceuticals, but , according to Elsa Ronningstam, psychologist at Harvard Medical School, "Alliance building and engaging the patient's sense of agency and reflective ability are essential for change in pathological narcissism."

Pattern change strategies performed over a long period of time are used to increase the ability of those with NPD to become more empathic in everyday relationships. To help modify their sense of entitlement and self-centeredness schema, the strategy is to help them identify how to utilize their unique talents and to help others for reasons other than their own personal gain. This is not so much to change their self-perception of their "entitlement" feeling but more to help them empathize with others. Another type of treatment would be temperament change. Psychoanalytic psychotherapy may be effective in treating NPD, but therapists must recognize the patient's traits and use caution in tearing down narcissistic defenses too quickly. Anger, rage, impulsivity, and impatience can be worked on with skill training. Therapy may not be effective because patients may receive feedback poorly and defensively. Anxiety disorders and somatoform dysfunctions are prevalent but the most common would be depression.

Group treatment has its benefits as the effectiveness of receiving peer feedback rather than the clinician's may be more accepted, but group therapy can also contradict itself as the patient may show "demandingness, egocentrism, social isolation and withdrawal, and socially deviant behavior". Researchers originally thought group therapy among patients with NPD would fail because it was believed that group therapy required empathy that NPD patients lack. However, studies show group therapy does hold value for patients with NPD because it lets them explore boundaries, develop trust, increase self-awareness, and accept feedback. Relationship therapy stresses the importance of learning and applying four basic interpersonal skills: "...effective expression, empathy, discussion and problem solving/conflict resolution". Marital/relationship therapy is most beneficial when both partners participate.

No medications are indicated for treating NPD, but may be used to treat co-occurring mental conditions or symptoms that may be associated with it such as depression, anxiety, and impulsiveness if present.

ASPD is considered to be among the most difficult personality disorders to treat. Because of their very low or absent capacity for remorse, individuals with ASPD often lack sufficient motivation and fail to see the costs associated with antisocial acts. They may only simulate remorse rather than truly commit to change: they can be seductively charming and dishonest, and may manipulate staff and fellow patients during treatment. Studies have shown that outpatient therapy is not likely to be successful, but the extent to which persons with ASPD are entirely unresponsive to treatment may have been exaggerated.

Those with ASPD may stay in treatment only as required by an external source, such as parole conditions. Residential programs that provide a carefully controlled environment of structure and supervision along with peer confrontation have been recommended. There has been some research on the treatment of ASPD that indicated positive results for therapeutic interventions.

Psychotherapy also known as talk therapy is found to help treat patients with ASPD.Schema therapy is also being investigated as a treatment for ASPD. A review by Charles M. Borduin features the strong influence of Multisystemic therapy (MST) that could potentially improve this imperative issue. However, this treatment requires complete cooperation and participation of all family members. Some studies have found that the presence of ASPD does not significantly interfere with treatment for other disorders, such as substance abuse, although others have reported contradictory findings.

Therapists working with individuals with ASPD may have considerable negative feelings toward patients with extensive histories of aggressive, exploitative, and abusive behaviors. Rather than attempt to develop a sense of conscience in these individuals, which is extremely difficult considering the nature of the disorder, therapeutic techniques are focused on rational and utilitarian arguments against repeating past mistakes. These approaches would focus on the tangible, material value of prosocial behavior and abstaining from antisocial behavior. However, the impulsive and aggressive nature of those with this disorder may limit the effectiveness of even this form of therapy.

The use of medications in treating antisocial personality disorder is still poorly explored, and no medications have been approved by the FDA to specifically treat ASPD. A 2010 Cochrane review of studies that explored the use of pharmaceuticals in ASPD patients, of which 8 studies met the selection criteria for review, concluded that the current body of evidence was inconclusive for recommendations concerning the use of pharmaceuticals in treating the various issues of ASPD. Nonetheless psychiatric medications such as antipsychotics, antidepressants, and mood stabilizers can be used to control symptoms such as aggression and impulsivity, as well as treat disorders that may co-occur with ASPD for which medications are indicated.

The effectiveness of psychotherapeutic and pharmacological interventions in the treatment of narcissistic personality disorder has yet to be systematically and empirically investigated. Clinical practice guidelines for the disorder have not yet been created, and current treatment recommendations are largely based on theoretical psychodynamic models of NPD and the experiences of clinicians with afflicted individuals in clinical settings.

The presence of NPD in patients undergoing psychotherapy for the treatment of other mental disorders is associated with slower treatment progress and higher dropout rates.

There are many different forms (modalities) of treatment used for personality disorders:

- Individual psychotherapy has been a mainstay of treatment. There are long-term and short-term (brief) forms.

- Family therapy, including couples therapy.

- Group therapy for personality dysfunction is probably the second most used.

- Psychological-education may be used as an addition.

- Self-help groups may provide resources for personality disorders.

- Psychiatric medications for treating symptoms of personality dysfunction or co-occurring conditions.

- Milieu therapy, a kind of group-based residential approach, has a history of use in treating personality disorders, including therapeutic communities.

- The practice of mindfulness that includes developing the ability to be nonjudgmentally aware of unpleasant emotions appears to be a promising clinical tool for managing different types of personality disorders.

There are different specific theories or schools of therapy within many of these modalities. They may, for example, emphasize psychodynamic techniques, or cognitive or behavioral techniques. In clinical practice, many therapists use an 'eclectic' approach, taking elements of different schools as and when they seem to fit to an individual client. There is also often a focus on common themes that seem to be beneficial regardless of techniques, including attributes of the therapist (e.g. trustworthiness, competence, caring), processes afforded to the client (e.g. ability to express and confide difficulties and emotions), and the match between the two (e.g. aiming for mutual respect, trust and boundaries).

Because of reduced levels of trust, there can be challenges in treating PPD. However, psychotherapy, antidepressants, antipsychotics and anti-anxiety medications can play a role when an individual is receptive to intervention.

Few medications are approved specifically for schizoaffective disorder. In general, medications are chosen to reduce symptoms of psychosis and mood disorder.

Antipsychotic medication is usually required both for acute treatment and the prevention of relapse. There is no single antipsychotic of choice in treating schizoaffective disorder, but atypical antipsychotics should be considered because they have mood-stabilizing activity. Paliperidone is an antipsychotic with FDA approval for the treatment of schizoaffective disorder. Antipsychotics should be used at the minimum dose necessary to control symptoms. Potential side effects include extrapyramidal symptoms, including tremor, muscle stiffness, and restlessness or akathisia. Atypical antipsychotics carry a risk of metabolic syndrome, including weight gain, increased blood sugar, and increased blood cholesterol, so regular monitoring of weight and bloodwork should be carried out. Some atypical antipsychotics, such as ziprasidone and aripiprazole, are associated with less risk than others, such as olanzapine. Medication choice is based on how effectively it reduces symptoms, how few side effects it causes, and cost.

In people with treatment-refractory psychosis, a clozapine trial should be considered. Clozapine is an atypical antipsychotic that is recognized as being particularly effective when other antipsychotic agents have failed. Clozapine should also be considered in people with chronic and persistent suicidal thinking and behaviour, as it has been shown to reduce the risk of suicide in patients with schizoaffective disorder and a history of suicidality. Between 0.5 and 2% of patients taking clozapine may develop a life-threatening complication called agranulocytosis, which is a significant drop in a type of white blood cell. Because of this risk, people taking clozapine must have regular monitoring of blood cell counts.

The management of the bipolar type of schizoaffective disorder is similar to the treatment of bipolar disorder, with the goal of preventing mood episodes and cycling. Lithium or anticonvulsant mood stabilizers such as valproic acid, carbamazepine, and lamotrigine are prescribed in combination with an antipsychotic.

For depression, if an antidepressant is prescribed, "extra attentiveness must be given" by the prescribing clinician due its risk for long-term mood cycle acceleration (that is, inducing more frequent episodes of depression per unit of time) and medication-induced psychosis or mania. For individuals who show emerging psychosis, mania, mixed episode symptoms, or mood cycle acceleration, switching to an antipsychotic plus lithium or lamotrigine is preferable to antidepressants.

For individuals who experience anxiety, anti-anxiety medications can be used, usually on a short-term basis. Benzodiazepines, including lorazepam, clonazepam and diazepam, are types of anti-anxiety medications. Care must be taken when prescribing benzodiazepines due to the risk of the patient developing tolerance and dependence.

The treatment of psychosis depends on the specific diagnosis (such as schizophrenia, bipolar disorder or substance intoxication). The first-line psychiatric treatment for many psychotic disorders is antipsychotic medication, which can reduce the positive symptoms of psychosis in about 7 to 14 days.

The choice of which antipsychotic to use is based on benefits, risks, and costs. It is debatable whether, as a class, typical or atypical antipsychotics are better. Tentative evidence supports that amisulpride, olanzapine, risperidone and clozapine may be more effective for positive symptoms but result in more side effects. Typical antipsychotics have equal drop-out and symptom relapse rates to atypicals when used at low to moderate dosages. There is a good response in 40–50%, a partial response in 30–40%, and treatment resistance (failure of symptoms to respond satisfactorily after six weeks to two or three different antipsychotics) in 20% of people. Clozapine is an effective treatment for those who respond poorly to other drugs ("treatment-resistant" or "refractory" schizophrenia), but it has the potentially serious side effect of agranulocytosis (lowered white blood cell count) in less than 4% of people.

Most people on antipsychotics get side effects. People on typical antipsychotics tend to have a higher rate of extrapyramidal side effects while some atypicals are associated with considerable weight gain, diabetes and risk of metabolic syndrome; this is most pronounced with olanzapine, while risperidone and quetiapine are also associated with weight gain. Risperidone has a similar rate of extrapyramidal symptoms to haloperidol.

Psychological treatments such as acceptance and commitment therapy (ACT) are possibly useful in the treatment of psychosis, helping people to focus more on what they can do in terms of valued life directions despite challenging symptomology.

Before beginning treatment for mania, careful differential diagnosis must be performed to rule out secondary causes.

The acute treatment of a manic episode of bipolar disorder involves the utilization of either a mood stabilizer (valproate, lithium, or carbamazepine) or an atypical antipsychotic (olanzapine, quetiapine, risperidone, or aripiprazole). Although hypomanic episodes may respond to a mood stabilizer alone, full-blown episodes are treated with an atypical antipsychotic (often in conjunction with a mood stabilizer, as these tend to produce the most rapid improvement).

When the manic behaviours have gone, long-term treatment then focuses on prophylactic treatment to try to stabilize the patient's mood, typically through a combination of pharmacotherapy and psychotherapy. The likelihood of having a relapse is very high for those who have experienced two or more episodes of mania or depression. While medication for bipolar disorder is important to manage symptoms of mania and depression, studies show relying on medications alone is not the most effective method of treatment. Medication is most effective when used in combination with other bipolar disorder treatments, including psychotherapy, self-help coping strategies, and healthy lifestyle choices.

Lithium is the classic mood stabilizer to prevent further manic and depressive episodes. A systematic review found that long term lithium treatment substantially reduces the risk of bipolar manic relapse, by 42%. Anticonvulsants such as valproate, oxcarbazepine and carbamazepine are also used for prophylaxis. More recent drug solutions include lamotrigine, which is another anticonvulsant. Clonazepam (Klonopin) is also used. Sometimes atypical antipsychotics are used in combination with the previous mentioned medications as well, including olanzapine (Zyprexa) which helps treat hallucinations or delusions, Asenapine (Saphris, Sycrest), aripiprazole (Abilify), risperidone, ziprasidone, and clozapine which is often used for people who do not respond to lithium or anticonvulsants.

Verapamil, a calcium-channel blocker, is useful in the treatment of hypomania and in those cases where lithium and mood stabilizers are contraindicated or ineffective. Verapamil is effective for both short-term and long-term treatment.

Antidepressant monotherapy is not recommended for the treatment of depression in patients with bipolar disorders I or II, and no benefit has been demonstrated by combining antidepressants with mood stabilizers in these patients.

Paranoid schizophrenia is an illness that typically requires lifelong treatment with neuroleptics to allow someone to have a relatively stable and normal lifestyle. In order to be successfully treated, a person with schizophrenia should seek help from family or primary care doctors, psychiatrists, psychotherapists, pharmacists, family members, case workers, psychiatric nurses, or social workers, provided he or she is not unable to do so, due to many people with schizophrenia having the inability to accept their condition. Non-compliance with neuroleptics may also occur if the patient considers the side effects (such as extrapyramidal symptoms) to be more debilitating than the condition itself. The main options that are offered for the treatment of paranoid schizophrenia are the following: neuroleptics, psychotherapy, hospitalization, electroconvulsive therapy, and vocational skills training.

There are many different types of disorders that have similar symptoms to paranoid schizophrenia. There are tests that psychiatrists perform to achieve a correct diagnosis. They include "psychiatric evaluation, in which the doctor or psychiatrist will ask a series of questions about the patient's symptoms, psychiatric history, and family history of mental health problems; medical history and exam, in which the doctor will ask about one's personal and family health history and will also perform a complete physical examination to check for medical issues that could be causing or contributing to the problem; laboratory tests in which the doctor will order simple blood and urine tests can rule out other medical causes of symptoms".

There are side effects associated with antipsychotic medication. Neuroleptics can cause high blood pressure and high cholesterol. Many people who take them exhibit weight gain and have a higher risk of developing diabetes.

Electroconvulsive therapy, or ECT, may be considered for patients with schizoaffective disorder experiencing severe depression or severe psychotic symptoms that have not responded to treatment with antipsychotics.

The management and treatment of personality disorders can be a challenging and controversial area, for by definition the difficulties have been enduring and affect multiple areas of functioning. This often involves interpersonal issues, and there can be difficulties in seeking and obtaining help from organizations in the first place, as well as with establishing and maintaining a specific therapeutic relationship. On the one hand, an individual may not consider themselves to have a mental health problem, while on the other, community mental health services may view individuals with personality disorders as too complex or difficult, and may directly or indirectly exclude individuals with such diagnoses or associated behaviors. The disruptiveness that people with personality disorders can create in an organisation makes these, arguably, the most challenging conditions to manage.

Apart from all these issues, an individual may not consider their personality to be disordered or the cause of problems. This perspective may be caused by the patient's ignorance or lack of insight into their own condition, an ego-syntonic perception of the problems with their personality that prevents them from experiencing it as being in conflict with their goals and self-image, or by the simple fact that there is no distinct or objective boundary between 'normal' and 'abnormal' personalities. Unfortunately, there is substantial social stigma and discrimination related to the diagnosis.

The term 'personality disorder' encompasses a wide range of issues, each with a different level of severity or disability; thus, personality disorders can require fundamentally different approaches and understandings. To illustrate the scope of the matter, consider that while some disorders or individuals are characterized by continual social withdrawal and the shunning of relationships, others may cause "fluctuations" in forwardness. The extremes are worse still: at one extreme lie self-harm and self-neglect, while at another extreme some individuals may commit violence and crime. There can be other factors such as problematic substance use or dependency or behavioral addictions. A person may meet the criteria for multiple personality disorder diagnoses and/or other mental disorders, either at particular times or continually, thus making coordinated input from multiple services a potential requirement.

Therapists in this area can become disheartened by lack of initial progress, or by apparent progress that then leads to setbacks. Clients may be perceived as negative, rejecting, demanding, aggressive or manipulative. This has been looked at in terms of both therapist and client; in terms of social skills, coping efforts, defense mechanisms, or deliberate strategies; and in terms of moral judgments or the need to consider underlying motivations for specific behaviors or conflicts. The vulnerabilities of a client, and indeed a therapist, may become lost behind actual or apparent strength and resilience. It is commonly stated that there is always a need to maintain appropriate professional personal boundaries, while allowing for emotional expression and therapeutic relationships. However, there can be difficulty acknowledging the different worlds and views that both the client and therapist may live with. A therapist may assume that the kinds of relationships and ways of interacting that make them feel safe and comfortable have the same effect on clients. As an example of one extreme, people who may have been exposed to hostility, deceptiveness, rejection, aggression or abuse in their lives, may in some cases be made confused, intimidated or suspicious by presentations of warmth, intimacy or positivity. On the other hand, reassurance, openness and clear communication are usually helpful and needed. It can take several months of sessions, and perhaps several stops and starts, to begin to develop a trusting relationship that can meaningfully address a client's issues.

Treatment consists of supportive care during the acute intoxication phase: maintaining hydration, body temperature, blood pressure, and heart rate at acceptable levels until the drug is sufficiently metabolized to allow vital signs to return to baseline. Typical and atypical antipsychotics have been shown to be helpful in the early stages of treatment. This is followed by abstinence from psychostimulants supported with counseling or medication designed to assist the individual preventing a relapse and the resumption of a psychotic state.

Lithium and the anticonvulsants carbamazepine, lamotrigine, and valproic acid are used as mood stabilizers to treat bipolar disorder. These mood stabilizers are used for long-term mood stabilization but have not demonstrated the ability to quickly treat acute bipolar depression. Lithium is preferred for long-term mood stabilization. Carbamazepine effectively treats manic episodes, with some evidence it has greater benefit in rapid-cycling bipolar disorder, or those with more psychotic symptoms or a more schizoaffective clinical picture. It is less effective in preventing relapse than lithium or valproate. Since then, valproate has become a commonly prescribed treatment, and is effective in treating manic episodes. Lamotrigine has some efficacy in treating bipolar depression, and this benefit is greatest in more severe depression. It has also been shown to have some benefit in preventing bipolar disorder relapses, though there are concerns about the studies done, and is of no benefit in rapid cycling subtype of bipolar disorder. The effectiveness of topiramate is unknown.

A number of medications are used to treat bipolar disorder. The medication with the best evidence is lithium, which is an effective treatment for acute manic episodes, preventing relapses, and bipolar depression. Lithium reduces the risk of suicide, self-harm, and death in people with bipolar disorder. It is unclear if ketamine is useful in bipolar as of 2015.

The most common treatment for reducing bipolar II disorder symptoms is medication, usually in the form of mood stabilizers. However, treatment with mood stabilizers may produce a flat affect in the patient, which is dose-dependent. Concurrent use of SSRI antidepressants may help some with bipolar II disorder, though these medications should be used with caution because it is believed that they may cause a hypomanic switch.

The pharmaceutical management of bipolar II disorder is not generally supported by strong evidence, with limited randomised controlled trials (RCTs) published in the literature. Some medications used are:

- Lithium - There is strong evidence that lithium is effective in treating both the depressive and hypomanic symptoms in bipolar II. In addition, its action as a mood stabilizer can be used to decrease the risk of hypomanic switch in patients treated with antidepressants.

- Anticonvulsants - there is evidence that lamotrigine decreases the risk of relapse in rapid cycling bipolar II. It appears to be more effective in bipolar II than bipolar I, suggesting that lamotrigine is more effective for the treatment of depressive rather than manic episodes. Doses ranging from 100–200 mg have been reported to have the most efficacy, while experimental doses of 400 mg have rendered little response. A large, multicentre trial comparing carbamazepine and lithium over two and a half years found that carbamazepine was superior in terms of preventing future episodes of bipolar II, although lithium was superior in individuals with bipolar I. There is also some evidence for the use of valproate and topiramate, although the results for the use of gabapentin have been disappointing.

- Antidepressants - there is evidence to support the use of SSRI and SNRI antidepressants in bipolar II. Indeed, some sources consider them to be one of the first line treatments. However, antidepressants also pose significant risks, including a switch to mania, rapid cycling, and dysphoria and so many psychiatrists advise against their use for bipolar. When used, antidepressants are typically combined with a mood stabilizer.

- Antipsychotics - there is good evidence for the use of quetiapine, and it has been approved by the FDA for this indication. There is also some evidence for the use of risperidone, although the relevant trial was not placebo controlled and was complicated by the use of other medications in some of the patients.

- Dopamine agonists - there is evidence for the efficacy of pramipexole from one RCT.

According to the Mayo Clinic, it is best to start receiving treatment for paranoid schizophrenia as early as possible and to maintain the treatment throughout life. Continuing treatment will help keep the serious symptoms under control and allow the person to lead a more fulfilling life. This illness is typically unpreventable.

It has a strong hereditary component with a first degree parent or sibling. There is some possibility that there are environmental influences including "prenatal exposure to a viral infection, low oxygen levels during birth (from prolonged labor or premature birth), exposure to a virus during infancy, early parental loss or separation, and verbal, physical or sexual abuse in childhood". Eliminating any of these factors could help reduce an individual's future risk of developing paranoid schizophrenia.

Treatment typically includes three things: the treatment of acute hypomania, the treatment of acute depression, and the prevention of the relapse of either hypomania or depression. The main goal is to make sure that patients do not harm themselves.

In patients suffering from schizophrenia, grandiose and religious delusions are found to be the least susceptible to cognitive behavioral interventions. Cognitive behavioral intervention is a form of psychological therapy, initially used for depression, but currently used for a variety of different mental disorders, in hope of providing relief from distress and disability. During therapy, grandiose delusions were linked to patients' underlying beliefs by using inference chaining. Some examples of interventions performed to improve the patient's state were focus on specific themes, clarification of neologisms, and thought linkage. During thought linkage, the patient is asked repeatedly by the therapist to explain his/her jumps in thought from one subject to a completely different one.

Patients suffering from mental disorders that experience grandiose delusions have been found to have a lower risk of having suicidal thoughts and attempts.

There are different types of treatments available for mood disorders, such as therapy and medications. Behaviour therapy, cognitive behaviour therapy and interpersonal therapy have all shown to be potentially beneficial in depression. Major depressive disorder medications usually include antidepressants, while bipolar disorder medications can consist of antipsychotics, mood stabilizers, anticonvulsants and/or lithium. Lithium specifically has been proven to reduce suicide and all causes of mortality in people with mood disorders. If mitochondrial dysfunction or mitochondrial diseases are the cause of mood disorders like bipolar disorder, then it has been hypothesized that N-acetyl-cysteine (NAC), acetyl-L-carnitine (ALCAR), S-adenosylmethionine (SAMe), coenzyme Q10 (CoQ10), alpha-lipoic acid (ALA), creatine monohydrate (CM), and melatonin could be potential treatment options.

Paranoia is an instinct or thought process believed to be heavily influenced by anxiety or fear, often to the point of delusion and irrationality. Paranoid thinking typically includes persecutory, or beliefs of concerning a perceived threat towards oneself (e.g. ""Everyone is out to get me"", which is an American parochial phrase). Paranoia is distinct from phobias, which also involve irrational fear, but usually no blame. Making false accusations and the general distrust of others also frequently accompany paranoia. For example, an incident most people would view as an accident or coincidence, a paranoid person might believe was intentional. Paranoia is a central symptom of psychosis. It is also a matter of personal tolerance for the individual that might be in conflict with psychiatric diagnoses.

Grandiosity refers to an unrealistic sense of superiority—a sustained view of oneself as better than others that causes the narcissist to view others with disdain or as inferior—as well as to a sense of uniqueness: the belief that few others have anything in common with oneself and that one can only be understood by a few or very special people. It also occurs in reactive attachment disorder.

Grandiosity is chiefly associated with narcissistic personality disorder, but also commonly features in manic or hypomanic episodes of bipolar disorder.

Paranoid personality disorder (PPD) is a mental disorder characterized by paranoia and a pervasive, long-standing suspiciousness and generalized mistrust of others. Individuals with this personality disorder may be hypersensitive, easily insulted, and habitually relate to the world by vigilant scanning of the environment for clues or suggestions that may validate their fears or biases. Paranoid individuals are eager observers. They think they are in danger and look for signs and threats of that danger, potentially not appreciating other evidence.

They tend to be guarded and suspicious and have quite constricted emotional lives. Their reduced capacity for meaningful emotional involvement and the general pattern of isolated withdrawal often lend a quality of schizoid isolation to their life experience. People with PPD may have a tendency to bear grudges, suspiciousness, tendency to interpret others' actions as hostile, persistent tendency to self-reference, or a tenacious sense of personal right. Patients with this disorder can also have significant comorbidity with other personality disorders.

A popular symptom of paranoia is the attribution bias. These individuals typically have a biased perception of reality, often exhibiting more hostile beliefs. A paranoid person may view someone else's accidental behavior as though it is with intent or threatening.

An investigation of a non-clinical paranoid population found that feeling powerless and depressed, isolating oneself, and relinquishing activities are characteristics that could be associated with those exhibiting more frequent paranoia.

Some scientists have created different subtypes for the various symptoms of paranoia including erotic, persecutory, litigious, and exalted.

Due to the suspicious and troublesome personality traits of paranoia, it is unlikely that someone with paranoia will thrive in interpersonal relationships. Most commonly paranoid individuals tend to be of a single status. According to some research there is a hierarchy for paranoia. The least common types of paranoia at the very top of the hierarchy would be those involving more serious threats. Social anxiety is at the bottom of this hierarchy as the most frequently exhibited level of paranoia.

There is limited evidence that caffeine, in high doses or when chronically abused, may induce psychosis in normal individuals and worsen pre-existing psychosis in those diagnosed with schizophrenia.