STPD is rarely seen as the primary reason for treatment in a clinical setting, but it often occurs as a comorbid finding with other mental disorders. When patients with STPD are prescribed pharmaceuticals, they are most often prescribed the same drugs used to treat patients suffering from schizophrenia including traditional neuroleptics such as haloperidol and thiothixene. In order to decide which type of medication should be used, Paul Markovitz distinguishes two basic groups of schizotypal patients:

- Schizotypal patients who appear to be almost schizophrenic in their beliefs and behaviors (aberrant perceptions and cognitions) are usually treated with low doses of antipsychotic medications, e.g. thiothixene. However, it must be mentioned that long-term efficacy of neuroleptics is doubtful.

- For schizotypal patients who are more obsessive-compulsive in their beliefs and behaviors, SSRIs like Sertraline appear to be more effective.

Lamotrigine, an anti-convulsant, appears to be helpful in dealing with social isolation.

A 2010 review by the Cochrane collaboration found that no medications show promise for "the core BPD symptoms of chronic feelings of emptiness, identity disturbance and abandonment". However, the authors found that some medications may impact isolated symptoms associated with BPD or the symptoms of comorbid conditions. A 2017 review examined evidence published since the 2010 Cochrane review and found that "evidence of effectiveness of medication for BPD remains very mixed and is still highly compromised by suboptimal study design".

Of the typical antipsychotics studied in relation to BPD, haloperidol may reduce anger and flupenthixol may reduce the likelihood of suicidal behavior. Among the atypical antipsychotics, one trial found that aripiprazole may reduce interpersonal problems and impulsivity. Olanzapine may decrease affective instability, anger, psychotic paranoid symptoms, and anxiety, but a placebo had a greater ameliorative impact on suicidal ideation than olanzapine did. The effect of ziprasidone was not significant.

Of the mood stabilizers studied, valproate semisodium may ameliorate depression, interpersonal problems, and anger. Lamotrigine may reduce impulsivity and anger; topiramate may ameliorate interpersonal problems, impulsivity, anxiety, anger, and general psychiatric pathology. The effect of carbamazepine was not significant. Of the antidepressants, amitriptyline may reduce depression, but mianserin, fluoxetine, fluvoxamine, and phenelzine sulfate showed no effect. Omega-3 fatty acid may ameliorate suicidality and improve depression. As of 2017, trials with these medications had not been replicated and the effect of long-term use had not been assessed.

Because of weak evidence and the potential for serious side effects from some of these medications, the UK National Institute for Health and Clinical Excellence (NICE) 2009 clinical guideline for the treatment and management of BPD recommends, "Drug treatment should not be used specifically for borderline personality disorder or for the individual symptoms or behavior associated with the disorder." However, "drug treatment may be considered in the overall treatment of comorbid conditions". They suggest a "review of the treatment of people with borderline personality disorder who do not have a diagnosed comorbid mental or physical illness and who are currently being prescribed drugs, with the aim of reducing and stopping unnecessary drug treatment".

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.

Research suggests that paraphrenics respond well to antipsychotic drug therapy if doctors can successfully achieve sufficient compliance. Herbert found that Stelazine combined with Disipal was an effective treatment. It promoted the discharging of patients and kept discharged patients from being readmitted later. While behavior therapy may help patients reduce their preoccupation with delusions, psychotherapy is not currently of primary value.

The first-line psychiatric treatment for schizophrenia is antipsychotic medication, which can reduce the positive symptoms of psychosis in about 7 to 14 days. Antipsychotics, however, fail to significantly improve the negative symptoms and cognitive dysfunction. In those on antipsychotics, continued use decreases the risk of relapse. There is little evidence regarding effects from their use beyond two or three years. However use of anti-psychotics can lead to dopamine hypersensitivity increasing the risk of symptoms if antipsychotics are stopped.

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. Amisulpride, olanzapine, risperidone, and clozapine may be more effective but are associated with greater 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 have 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. It remains unclear whether the newer antipsychotics reduce the chances of developing neuroleptic malignant syndrome or tardive dyskinesia, a rare but serious neurological disorder.

For people who are unwilling or unable to take medication regularly, long-acting depot preparations of antipsychotics may be used to achieve control. They reduce the risk of relapse to a greater degree than oral medications. When used in combination with psychosocial interventions, they may improve long-term adherence to treatment. The American Psychiatric Association suggests considering stopping antipsychotics in some people if there are no symptoms for more than a year.

A major option for many mental disorders is psychiatric medication and there are several main groups. Antidepressants are used for the treatment of clinical depression, as well as often for anxiety and a range of other disorders. Anxiolytics (including sedatives) are used for anxiety disorders and related problems such as insomnia. Mood stabilizers are used primarily in bipolar disorder. Antipsychotics are used for psychotic disorders, notably for positive symptoms in schizophrenia, and also increasingly for a range of other disorders. Stimulants are commonly used, notably for ADHD.

Despite the different conventional names of the drug groups, there may be considerable overlap in the disorders for which they are actually indicated, and there may also be off-label use of medications. There can be problems with adverse effects of medication and adherence to them, and there is also criticism of pharmaceutical marketing and professional conflicts of interest.

The primary treatment of schizophrenia is antipsychotic medications, often in combination with psychological and social supports. Hospitalization may occur for severe episodes either voluntarily or (if mental health legislation allows it) involuntarily. Long-term hospitalization is uncommon since deinstitutionalization beginning in the 1950s, although it still occurs. Community support services including drop-in centers, visits by members of a community mental health team, supported employment and support groups are common. Some evidence indicates that regular exercise has a positive effect on the physical and mental health of those with schizophrenia.

According to Theodore Millon, the schizotypal is one of the easiest personality disorders to identify but one of the most difficult to treat with psychotherapy. Persons with STPD usually consider themselves to be simply eccentric, productive, or nonconformist. As a rule, they underestimate maladaptiveness of their social isolation and perceptual distortions. It is not so easy to gain rapport with people who suffer from STPD due to the fact that increasing familiarity and intimacy usually increase their level of anxiety and discomfort. In most cases they do not respond to informality and humor.

Group therapy is recommended for persons with STPD only if the group is well structured and supportive. Otherwise, it could lead to loose and tangential ideation. Support is especially important for schizotypal patients with predominant paranoid symptoms, because they will have a lot of difficulties even in highly structured groups.

As it has already been mentioned, patients with organic personality disorder show a wide variety of sudden behavioural changes and dysfunctions. There are not a lot of information about the treatment of this mental health disorder. The pharmacological approach is the most common therapy among patients with organic personality disorder. However, the choice of drug therapy relies on the seriousness of patient's situation and what symptoms are shown. The choice and administration of specific drugs contribute to the reduction of symptoms of organic personality disorder. For this reason, it is crucial for patients' treatment to be assessed by clinical psychologists and psychiatrists before the administration of drug.

Additionally, the dysfunctions in expression of behaviour of patients with organic personality disorder and the development of symptom of irritability, which are caused by aggressive and self-injurious behaviours, can be dealt with the administration of carbamazepine. Moreover, the symptoms of this disorder can be decreased by the administration of valproic acid. Also, emotional irritability and signs of depression can be dealt with the use of nortriptyline and low-dose thioridazine. Except from the symptom of irritability, patients express aggressive behaviours. At the onset of drug therapy for effective treatment of anger and aggression, the drug of carbamazepine, phenobarbital, benztropine and haloperidol can be administrated in order to reduce the symptoms of patients with organic personality disorder. In addition, the use of propranolol may decrease the frequent behaviours of rage attacks.

Finally, it is important for patients to take part in psychotherapy sessions during the period of drug therapy. In this way, there is prevention and patients can be protected by negative effects of drugs on their organism and their behaviour. Furthermore, the clinicians can provide useful and helpful support to patients during these psychotherapy sessions. Thus, the combination of drug therapy with psychotherapy can lead to the reduction of symptoms of this disorder and the improvement of patients' situation.

No medications are indicated for directly treating schizoid personality disorder, but certain medications may reduce the symptoms of SPD as well as treat co-occurring mental disorders. The symptoms of SPD mirror the negative symptoms of schizophrenia, such as anhedonia, blunted affect and low energy, and SPD is thought to be part of the "schizophrenic spectrum" of disorders, which also includes the schizotypal and paranoid personality disorders, and may benefit from the medications indicated for schizophrenia. Originally, low doses of atypical antipsychotics like risperidone or olanzapine were used to alleviate social deficits and blunted affect. However, a recent review concluded that atypical antipsychotics were ineffective for treating personality disorders. In contrast, the substituted amphetamine Bupropion may be used to treat anhedonia. Likewise, Modafinil may be effective in treating some of the negative symptoms of schizophrenia, which are reflected in the symptomatology of SPD and therefore may help as well. Lamotrigine, SSRIs, TCAs, MAOIs and Hydroxyzine may help counter social anxiety in people with SPD if present, though social anxiety may not be a main concern for the people who have SPD. However, it is not general practice to treat SPD with medications, other than for the short term treatment of acute co-occurring Axis I conditions (e.g. depression).

Electroconvulsive therapy (ECT) is sometimes used in severe cases when other interventions for severe intractable depression have failed. Psychosurgery is considered experimental but is advocated by some neurologists in certain rare cases.

Counseling (professional) and co-counseling (between peers) may be used. Psychoeducation programs may provide people with the information to understand and manage their problems. Creative therapies are sometimes used, including music therapy, art therapy or drama therapy. Lifestyle adjustments and supportive measures are often used, including peer support, self-help groups for mental health and supported housing or supported employment (including social firms). Some advocate dietary supplements.

Reasonable accommodations (adjustments and supports) might be put in place to help an individual cope and succeed in environments despite potential disability related to mental health problems. This could include an emotional support animal or specifically trained psychiatric service dog.

A widely accepted treatment for the syndrome of subjective doubles has not been developed. Treatment methods for this disease sometimes include the prescription of antipsychotic drugs, however, the type of drug prescribed depends on the presence of other mental disorders. Antipsychotic drugs (also known as neuroleptics) such as risperidone, pimozide, or haloperidol may be prescribed to treat the underlying psychiatric illness.

In addition to drug therapy, interpersonal counseling has also been suggested as a method to ease relations between the patient and his/her suspected doubles. However, the relationship between the patient and his/her double is not always negative.

Long-term psychotherapy is currently the treatment of choice for BPD. While psychotherapy, in particular dialectical behavior therapy and psychodynamic approaches, is effective, the effects are small.

More rigorous treatments are not substantially better than less rigorous treatments. There are six such treatments available: dynamic deconstructive psychotherapy (DDP), mentalization-based treatment (MBT), transference-focused psychotherapy, dialectical behavior therapy (DBT), general psychiatric management, and schema-focused therapy. While DBT is the therapy that has been studied the most, all these treatments appear effective for treating BPD, except for schema-focused therapy. Long-term therapy of any kind, including schema-focused therapy, is better than no treatment, especially in reducing urges to self-injure.

Cognitive behavioral therapy (CBT) is also a type of psychotherapy used for treatment of BPD. This type of therapy relies on changing people's behaviors and beliefs by identifying problems from the disorder. CBT is known to reduce some anxiety and mood symptoms as well as reduce suicidal thoughts and self-harming behaviors.

Mentalization-based therapy and transference-focused psychotherapy are based on psychodynamic principles, and dialectical behavior therapy is based on cognitive-behavioral principles and mindfulness. General psychiatric management combines the core principles from each of these treatments, and it is considered easier to learn and less intensive. Randomized controlled trials have shown that DBT and MBT may be the most effective, and the two share many similarities. Researchers are interested in developing shorter versions of these therapies to increase accessibility, to relieve the financial burden on patients, and to relieve the resource burden on treatment providers.

From a psychodynamic perspective, a special problem of psychotherapy with people with BPD is intense projection. It requires the psychotherapist to be flexible in considering negative attributions by the patient rather than quickly interpreting the projection.

Some research indicates that mindfulness meditation may bring about favorable structural changes in the brain, including changes in brain structures that are associated with BPD. Mindfulness-based interventions also appear to bring about an improvement in symptoms characteristic of BPD, and some clients who underwent mindfulness-based treatment no longer met a minimum of five of the DSM-IV-TR diagnostic criteria for BPD.

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.

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).

People with schizoid personality disorder rarely seek treatment for their condition. This is an issue found in many personality disorders, which prevents many people who are afflicted with these conditions from coming forward for treatment: They tend to view their condition as not conflicting with their self-image and their abnormal perceptions and behaviors as rational and appropriate. There is little data on the effectiveness of various treatments on this personality disorder because it is seldom seen in clinical settings. However, those in treatment have the option of medication and therapy.

Medications for schizophrenia are often used, especially when positive symptoms are present. Both first-generation antipsychotics and second-generation antipsychotics may be useful. Cognitive behavioral therapy has also been used.

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.

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.

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.

Recovery from this syndrome is situational, as some drug therapies have been effective in some individuals but not others. Patients may live in a variety of settings, including psychiatric hospitals, depending on the success of treatment. With successful treatment, an individual may live at home. In many of the reported cases, remission of symptoms occurred during the follow-up period.

This disorder can be dangerous to the patient and others, as a patient may interrogate or attack a person they believe to be a double. Inappropriate behavior such as stalking and physical or psychological abuse has been documented in some case studies. Consequently, many individuals suffering from this disorder are arrested for the resulting misconduct (see the case of Mr. B in #Presentation).

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.

Treatment of avoidant personality disorder can employ various techniques, such as social skills training, cognitive therapy, and exposure treatment to gradually increase social contacts, group therapy for practicing social skills, and sometimes drug therapy.

A key issue in treatment is gaining and keeping the patient's trust, since people with avoidant personality disorder will often start to avoid treatment sessions if they distrust the therapist or fear rejection. The primary purpose of both individual therapy and social skills group training is for individuals with avoidant personality disorder to begin challenging their exaggerated negative beliefs about themselves.

Significant improvement in the symptoms of personality disorders is possible, with the help of treatment and individual effort.

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.

Individual therapy may be best suited to treat the individual's delusions. Persistence is needed in establishing a therapeutic empathy without validating the patient’s delusional system or overtly confronting the system. Cognitive techniques that include reality testing and reframing can be used. Antipsychotics and other therapeutic drugs have been used with relative success.