Education, and a "watch and wait" strategy, are the only treatment needed for many, and the majority of individuals with tics do not seek treatment; treatment of tic disorders is similar to treatment of Tourette syndrome.

Once the patient and family have been educated about the nature, management and treatment of the disorder and a decision has been made to treat, the European ADHD Guidelines group recommends medication rather than behavioral training as the first treatment approach; and the UK's National Institute for Health and Clinical Excellence recommends medication as first line treatment for those with hyperkinesis/severe ADHD, and the provision of group parent-training in all cases of ADHD.

There is no consistently effective medication for SMD, and there is little evidence for any effective treatment. In non-autistic or "typically developing children", habit reversal training may be useful. No treatment is an option when movements are not interfering with daily life.

Prognosis depends on the severity of the disorder. Recognizing symptoms early can help reduce the risk of self-injury, which can be lessened with meditations. Stereotypic movement disorder due to head trauma may be permanent.

Tic disorders are more common among males than females.

A large, community-based study suggested that over 19% of school-age children have tic disorders; the children with tic disorders in that study were usually undiagnosed.

As many as 1 in 100 people may experience some form of tic disorder, usually before the onset of puberty. Tourette syndrome is the more severe expression of a spectrum of tic disorders, which are thought to be due to the same genetic vulnerability. Nevertheless, most cases of Tourette syndrome are not severe. Although a significant amount of investigative work indicates genetic linkage of the various tic disorders, further study is needed to confirm the relationship.

There are several different classes of pharmacological treatment agents that have some support for treating excoriation disorder: (1) SSRIs; (2) opioid antagonists; and (3) glutamatergic agents. In addition to these classes of drugs, some other pharmacological products have been tested in small trials as well.

SSRIs have shown to be effective in the treatment of OCD and this has provided an argument in favor of treating excoriation disorder with the same therapy. Unfortunately, the clinical studies have not provided clear support for this, because there have not been large double-blind placebo-controlled trials of SSRI therapy for excoriation disorder.

Review of treatment of excoriation disorder have shown that the following medications may be effective in reducing picking behavior: doxepin, clomipramine, naltrexone, pimozide, and olanzapine. Small studies of fluoxetine, an SSRI, in treating excoriation disorder showed that the drug reduced certain aspects of skin picking, as compared to placebo, but full remission was not observed. One small study of patients with excoriation disorder treated with citalopram, another SSRI, showed that those that took the drug significantly reduced their scores on the Yale-Brown Obsessive Compulsive Scale compared to placebo, but that there was no significant decrease on the visual-analog scale of picking behavior.

While there have been no human studies of opioid antagonists for the treatment of excoriation disorder, there have been studies showing that these products can reduce self-chewing in dogs with acral lick, which some have proposed is a good animal model for the body-focused repetitive behavior. Furthermore, there have been case reports that support the use of these opioid antagonists to treat excoriation disorder. Opioid antagonists work by affecting dopamine circuitry, thereby decreasing the pleasurable effects of picking.

Another class of possible pharmacological treatments are glutamatergic agents such as n-acetyl cysteine (NAC). These products have shown some ability to reduce other problematic behaviors such as cocaine addiction and trichotillomania. Some case studies and some small studies of NAC have shown a decrease in picking by treatment with NAC, as compared to placebo.

Excoriation disorder, and trichotillomania have been treated with inositol.

Topiramate, an anti-epileptic drug, has been used to treat excoriation disorder; in a small study of individuals with Prader–Willi syndrome, it was found to reduce skin picking.

Knowledge about effective treatments for excoriation disorder is sparse despite the prevalence of the condition. There are two major classes of therapy for excoriation disorder: pharmacological and behavioral.

Individuals with excoriation disorder often do not seek treatment for their condition largely due to feelings of embarrassment, alienation, lack of awareness, or belief that the condition cannot be treated. One study found that only 45% of individuals with excoriation disorder ever sought treatment and only 19% ever received dermalogical treatment. Another study found that only 30% of individuals with this disorder sought treatment.

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.

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.

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.

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.

Personality development disorders usually need a complex and multi-dimensional treatment approach (Adam & Breithaupt-Peters, 2010). Since the problems are complex, treatment needs to affect the conditions in all impaired functional and social areas. Both educational and therapeutic methods are helpful and problem and strength based approaches work hand in hand. Parents need to be included as well as the school environment. Treatment methods need to be flexible and adjustable to the individual situation. Even elements of social work can be helpful when supporting the families and in some cases medication might be necessary. When suicidal behaviors or self-injuries are prominent treatment might best be done in a hospital.

For some personality development disorders (e.g. borderline personality disorder) treatment methods from adults can be adapted (e.g. dialectical behavior therapy, Miller et a., 2006).

Multiple complex developmental disorder (MCDD) is a research category, proposed to involve several neurological and psychological symptoms where at least some symptoms are first noticed during early childhood and persist throughout life. It was originally suggested to be a subtype of autistic spectrum disorders (PDD) with co-morbid schizophrenia or another psychotic disorder; however, there is some controversy that not everyone with MCDD meets criteria for both PDD and psychosis. The term "multiplex developmental disorder" was coined by Donald J. Cohen in 1986.

The rate in school age children is thought to be about 1.5%, compared with an estimated 5.3% for ADHD.

It is possible for this disorder to progress over time. A patient suffering from the disorder can improve the condition with treatments. There are several types of therapies that may improve the condition, but depending on a patient’s experience of the disorder or the cause of the disorder, treatments will vary.

- Psychotherapy including behaviour therapy, Gestalt therapy, Adlerian therapy, psychoanalytic therapy and existential therapy.

- Pharmacotherapy through medications including antidepressants.

Multiple complex developmental disorder is likely to be caused by a number of different various genetic factors. Each individual with MCDD is unique from one another and displays different symptoms. Various neuropsychological disorders can also be found in family members of people with MCDD.

Individual approaches to treatment are recommended, usually involving a combination of mood stabilizers and atypical antipsychotics. Psychotherapy may be beneficial and should be started early.

Organic personality disorder (OPD) is not included in the wide variety of group of personality disorders. For this reason, the symptoms and diagnostic criteria of the organic personality disorder are different from those of the mental health disorders, which are included in this various group of personality disorders. According to the Tenth Revision of the International Statistical Classification of Diseases and Related Health Problems ICD-10, it defines the organic personality disorder as the personality change, which can be caused by traumatic brain injury (TBI) that means there are specific brain areas of patients, which have been injured after a very strong accident. Moreover, according to the ICD-10, the organic personality disorder is associated with a "significant alteration of the habitual patterns of premorbid behaviour". Furthermore, organic personality disorder is associated with "personality change due to general medical condition". There are crucial influences on emotions, impulses and personal needs because of this disorder. Thus, all these definitions about the organic personality disorder support that this type of disorder is associated with changes in personality and 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.

No true psychiatric medications are prescribed for factitious disorder. However, selective serotonin reuptake inhibitors (SSRIs) can help manage underlying problems. Medicines such as SSRIs that are used to treat mood disorders can be used to treat FD, as a mood disorder may be the underlying cause of FD. Some authors (such as Prior and Gordon 1997) also report good responses to antipsychotic drugs such as Pimozide. Family therapy can also help. In such therapy, families are helped to better understand patients (the individual in the family with FD) and that person's need for attention.

In this therapeutic setting, the family is urged not to condone or reward the FD individual's behavior. This form of treatment can be unsuccessful if the family is uncooperative or displays signs of denial and/or antisocial disorder. Psychotherapy is another method used to treat the disorder. These sessions should focus on the psychiatrist's establishing and maintaining a relationship with the patient. Such a relationship may help to contain symptoms of FD. Monitoring is also a form that may be indicated for the FD patient's own good; FD (especially proxy) can be detrimental to an individual's health—if they are, in fact, causing true physiological illnesses. Even faked illnesses/injuries can be dangerous, and might be monitored for fear that unnecessary surgery may subsequently be performed.

Somatization disorder (also Briquet's syndrome) is a mental disorder characterized by recurring, multiple, and current, clinically significant complaints about somatic symptoms, although it is no longer considered a clinical diagnosis. It was recognized in the DSM-IV-TR classification system, but in the latest version DSM-5, it was combined with undifferentiated somatoform disorder to become "somatic symptom disorder", a diagnosis which no longer requires a specific number of somatic symptoms. ICD-10, the latest version of the International Statistical Classification of Diseases and Related Health Problems, still includes somatization syndrome.

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.

There are a number of different treatments that are available to treat and manage conversion syndrome. Treatments for conversion syndrome include hypnosis, psychotherapy, physical therapy, stress management, and transcranial magnetic stimulation. Treatment plans will consider duration and presentation of symptoms and may include one or multiple of the above treatments. This may include the following:

1. Explanation. This must be clear and coherent as attributing physical symptoms to a psychological cause is not accepted by many educated people in western cultures. It must emphasize the genuineness of the condition, that it is common, potentially reversible and does not mean that the sufferer is psychotic. Taking a neutral-cause-based stance by describing the symptoms as functional may be helpful, but further studies are required. Ideally, the patient should be followed up neurologically for a while to ensure that the diagnosis has been understood.

2. Physiotherapy where appropriate;

3. Occupational Therapy to maintain autonomy in activities of daily living;

4. Treatment of comorbid depression or anxiety if present.

There is little evidence-based treatment of conversion disorder. Other treatments such as cognitive behavioral therapy, hypnosis, EMDR, and psychodynamic psychotherapy, EEG brain biofeedback need further trials. Psychoanalytic treatment may possibly be helpful. However, most studies assessing the efficacy of these treatments are of poor quality and larger, better controlled studies are urgently needed. Cognitive Behavioural Therapy is the most common treatment, however boasts a mere 13% improvement rate.

Psychotherapy, more specifically, cognitive behavioral therapy (CBT), is the most widely used form of treatment for Somatic symptom disorder. In 2016, a randomized 12-week study suggested steady and significant improvement in health anxiety measures with cognitive behavioral therapy compared to the control group.

CBT can help in some of the following ways:

- Learn to reduce stress

- Learn to cope with physical symptoms

- Learn to deal with depression and other psychological issues

- Improve quality of life

- Reduce preoccupation with symptom

Moreover, brief psychodynamic interpersonal psychotherapy (PIT) for patients with multisomatoform disorder has shown its long-term efficacy for improving the physical quality of life in patients with multiple, difficult-to-treat, medically unexplained symptoms.

Antidepressant medication has also been used to treat some of the symptoms of depression and anxiety that are common among people who have somatic symptom disorder. Medications will not cure somatic symptom disorder, but can help the treatment process when combined with CBT.