Treatment for OCPD includes psychotherapy, cognitive behavioral therapy, behavior therapy or self-help. Medication may be prescribed. In behavior therapy, a person with OCPD discusses with a psychotherapist ways of changing compulsions into healthier, productive behaviors. Cognitive analytic therapy is an effective form of behavior therapy.

Treatment is complicated if the person does not accept that they have OCPD, or believes that their thoughts or behaviors are in some sense correct and therefore should not be changed. Medication alone is generally not indicated for this personality disorder. Selective serotonin reuptake inhibitors (SSRIs) may be useful in addition to psychotherapy by helping the person with OCPD be less bogged down by minor details, and to lessen how rigid they are.

People with OCPD are three times more likely to receive individual psychotherapy than people with major depressive disorder. There are higher rates of primary care utilization. There are no known properly controlled studies of treatment options for OCPD. More research is needed to explore better treatment options.

The cause of OCPD is unknown. However, it is believed to involve a combination of genetic and environmental factors. Under the genetic theory, people with a form of the DRD3 gene will probably develop OCPD and depression, particularly if they are male. But genetic concomitants may lie dormant until triggered by events in the lives of those who are predisposed to OCPD. These events could include trauma faced during childhood, such as physical, emotional, or sexual abuse, or other psychological trauma. Under the environmental theory, OCPD is a learned behavior.

The most effective treatment for an individual with conduct disorder is one that seeks to integrate individual, school, and family settings. Additionally, treatment should also seek to address familial conflict such as marital discord or maternal depression.

Despite recent initiatives to study psychopathology along dimensions of behavior and neurobiological indices, which would help refine a clearer picture of the development and treatment of externalizing disorders, the majority of research has examined specific mental disorders. Thus, best practices for many externalizing disorders are disorder-specific. For example, substance use disorders themselves are very heterogeneous and their best-evidenced treatment typically includes cognitive behavioral therapy, motivational interviewing, and a substance disorder-specific detoxification or psychotropic medication treatment component. The best-evidenced treatment for childhood conduct and externalizing problems more broadly, including youth with ADHD, ODD, and CD, is parent management training, a form of cognitive behavioral therapy. Additionally, individuals with ADHD, both youth and adults, are frequently treated with stimulant medications (or alternative psychotropic medications), especially if psychotherapy alone has not been effective in managing symptoms and impairment. Psychotherapy and medication interventions for individuals with severe, adult forms of antisocial behavior, such as antisocial personality disorder, have been mostly ineffective. An individual's comorbid psychopathology may also influences the course of treatment for an individual.

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".

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.

There is a significant difference between the number of those who would benefit from treatment and the number of those who are treated. The so-called "treatment gap" is a function of the disinclination of the afflicted to submit for treatment, an underdiagnosing of the disorder by healthcare providers, and the limited availability and access to state-of-the-art treatments. Nonetheless, individuals with BPD accounted for about 20 percent of psychiatric hospitalizations in one survey. The majority of individuals with BPD who are in treatment continue to use outpatient treatment in a sustained manner for several years, but the number using the more restrictive and costly forms of treatment, such as inpatient admission, declines with time.

Experience of services varies. Assessing suicide risk can be a challenge for clinicians, and patients themselves tend to underestimate the lethality of self-injurious behaviors. People with BPD typically have a chronically elevated risk of suicide much above that of the general population and a history of multiple attempts when in crisis. Approximately half the individuals who commit suicide meet criteria for a personality disorder. Borderline personality disorder remains the most commonly associated personality disorder with suicide.

After the death of a patient in 2014 NHS England was criticised by a coroner for the lack of commissioned services to support such patients. Evidence was given that 45% of mentally disordered females had BPD and there was no provision or priority for therapeutic psychological services. There were only 60 specialised inpatient beds in England – all in the North East or London.

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.

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.

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.

Being a personality disorder, which are usually chronic and long-lasting mental conditions, avoidant personality disorder is not expected to improve with time without treatment. It is a poorly studied personality disorder and in light of prevalence rates, societal costs, and the current state of research, AvPD qualifies as a neglected disorder.

Currently, genetic research for the understanding of the development of personality disorders is severely lacking. However, there are a few possible risk factors currently in discovery. Researchers are currently looking into genetic mechanisms for traits such as aggression, fear and anxiety, which are associated with diagnosed individuals. More research is being conducted into disorder specific mechanisms.

While the cause of conduct disorder is complicated by an intricate interplay of biological and environmental factors, identifying underlying mechanisms is crucial for obtaining accurate assessment and implementing effective treatment. These mechanisms serve as the fundamental building blocks on which evidence-based treatments are developed. Despite the complexities, several domains have been implicated in the development of conduct disorder including cognitive variables, neurological factors, intraindividual factors, familial and peer influences, and wider contextual factors. These factors may also vary based on the age of onset, with different variables related to early (e.g., neurodevelopmental basis) and adolescent (e.g., social/peer relationships) onset.

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).

Dependent personality disorder occurs in about 0.6% of the general population. The disorder is diagnosed more often in females than males; however, research suggests that this is largely due to behavioural differences in interviews and self-reporting rather than a difference in prevalence between the sexes. A 2004 twin study suggests a heritability of 0.81 for developing dependent personality disorder. Because of this, there is significant evidence that this disorder runs in families. Children and adolescents with a history of anxiety disorders and physical illnesses are more susceptible to acquiring this disorder.

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.

Treatment is often prompted by depression associated with dissolved romantic relationships. Medication does little to affect the personality disorder, but may be helpful with symptoms such as depression. Treatment for HPD itself involves psychotherapy, including cognitive therapy.

Another example of treatment besides coding is Functional Ideographic Assessment Template. The functional ideographic assessment template, also known as FIAT, was used as a way to generalize the clinical processes of functional analytic psychotherapy. The template was made by a combined effort of therapists and can be used to represent the behaviors that are a focus for this treatment. Using the FIAT therapists can create a common language to get stable and accurate communication results through functional analytic psychotherapy at the ease of the client; as well as the therapist.

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).

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.

The World Health Organization's ICD-10 lists dependent personality disorder as " Dependent personality disorder":

It is characterized by at least 4 of the following:

1. Encouraging or allowing others to make most of one's important life decisions;

2. Subordination of one's own needs to those of others on whom one is dependent, and undue compliance with their wishes;

3. Unwillingness to make even reasonable demands on the people one depends on;

4. Feeling uncomfortable or helpless when alone, because of exaggerated fears of inability to care for oneself;

5. Preoccupation with fears of being abandoned by a person with whom one has a close relationship, and of being left to care for oneself;

6. Limited capacity to make everyday decisions without an excessive amount of advice and reassurance from others.

Associated features may include perceiving oneself as helpless, incompetent, and lacking stamina.

Includes:

- Asthenic, inadequate, passive, and self-defeating personality (disorder)

It is a requirement of ICD-10 that a diagnosis of any specific personality disorder also satisfies a set of general personality disorder criteria.

According to Professor Emily Simonoff of the Institute of Psychiatry, Psychology and Neuroscience, "childhood hyperactivity and conduct disorder showed equally strong prediction of antisocial personality disorder (ASPD) and criminality in early and mid-adult life. Lower IQ and reading problems were most prominent in their relationships with childhood and adolescent antisocial behaviour."

Externalizing disorders are frequently comorbid or co-occurring with other disorders. Individuals who have the co-occurrence of more than one externalizing disorder have homotypic comorbidity, whereas individuals who have co-occurring externalizing and Internalizing disorders have heterotypic comorbidity. It is not uncommon for children with early externalizing problems to develop both internalizing and further externalizing problems across the lifespan.

Psychiatrist Kantor suggests a treatment approach using psychodynamic, supportive, cognitive, behavioral and interpersonal therapeutic methods. These methods apply to both the Passive–aggressive person and their target victim.

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.