The World Health Organization's (WHO) "International Statistical Classification of Diseases and Related Health Problems", 10th Edition (ICD-10) lists narcissistic personality disorder under "Other specific personality disorders". It is a requirement of ICD-10 that a diagnosis of any specific personality disorder also satisfies a set of general personality disorder criteria.

NPD has a high rate of comorbidity with other mental disorders. Individuals with NPD are prone to bouts of depression, often meeting criteria for co-occurring depressive disorders. In addition, NPD is associated with bipolar disorder, anorexia, and substance use disorders, especially cocaine. As far as other personality disorders, NPD may be associated with histrionic, borderline, antisocial, and paranoid personality disorders.

A fixed fantasy — also known as a "dysfunctional schema" — is a belief or system of beliefs held by a single individual to be genuine, but that cannot be verified in reality. The term is typically applied to individuals suffering from some type of psychiatric dysregulation, most often a personality disorder.

The term is also used in the different context of psychoanalysis to distinguish between 'a normal transitory one and a fixed fantasy' with respect to the phantasised 'fulfilment in conscious or unconscious thought of the sexualised wish'.

Otherkin largely identify as mythical creatures, with others identifying as creatures from fantasy or popular culture. Examples include: angels, demons, dragons, goats, elves, fairies, sprites, aliens, and cartoon characters. Many otherkin believe in the existence of a multitude of parallel universes, and their belief in the existence of supernatural or sapient non-human beings is grounded in that idea.

With regards to their online communities, otherkin largely function without formal authority structures, and mostly focus on support and information gathering, often dividing into more specific groups based on kintype. There are occasional offline gatherings, but the otherkin network is mostly an online phenomenon.

Some otherkin (such as elvenkin) state they are allergic to iron (and products of modern technology), while others (such as dragonkin) state that having no allergies is a sign of otherkin condition. Some otherkin also claim to be especially empathic and attuned to nature. Some state to be able to shapeshift mentally or astrally, meaning that they experience the sense of being in their particular form while not actually changing physically.

The therian and vampire subcultures are related to the otherkin community, and are considered part of it by most otherkin, but are culturally and historically distinct movements of their own, despite some overlap in membership.

Otherkin are a subculture who socially and spiritually identify as partially or entirely non-human. Some of them surmise that they are, either spiritually or genetically, not human; however, this claim is unsubstantiated. This is explained by some members of the otherkin community as possible through reincarnation, having a non-human soul, ancestry, or symbolic metaphor. Some scholars categorize this identity claim as "religious", because it is largely based on supernatural beliefs. Adherents more typically deny the religiosity of otherkinism, referring to it instead as simply a congenital condition, or a metaphysical state of being.

Studies of borderline children often uncovered at the base of their self-destructive behaviour patterns ' a "fixed fantasy"...a rigid, nonreflective scenario of self-induced pain'. As part of a psychic defence mechanism, 'the omnipotence betrayed by the "fixed fantasy" underlying self-victimization or other forms of self-defeating behaviour...creates the illusory sense that they are actively producing the abandonment [&] pain', rather than merely suffering it passively - 'arranging deceits..arrang[ing] for blows to fall'. Unfortunately 'in the course of development, these patterns acquire multiple adaptive functions...and serve as a key organizer of their sense of self'.

'In producing movement away from fixed fantasy systems, commonplace statements are often necessary because the more fixed and extensive the fantasy system, the fewer the transitional opportunities offered; there is little conflicting material to ride. Banalities may be the only resource', as anything more complex may be used to feed back into the fantasy system itself.

The FDA has approved one medication for the treatment of disorders of female libido, flibanserin.

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.

Money disorders are the maladaptive patterns of financial beliefs and behaviors that lead to clinically significant distress, impairment in social or occupational functioning, due to financial strain or an inability to appropriately enjoy one’s financial resources. With the exception of pathological gambling and compulsive buying, psychology and the mental health fields have largely neglected dysfunctional money disorders. The term is contentious among mental health professionals and as of 2017, money disorder is not a clinical diagnosis in either the DSM or ICD medical classifications of diseases and medical disorders.

Types of behaviors, or “scripts”, related to money disorders include money avoidance, money worship, money status and money vigilance. Some mental health practitioners say that those afflicted with money disorders or who have problematic money beliefs can seek financial therapy. With financial therapy, financial planners and relationship therapists work together to provide comprehensive treatment to clients experiencing financial distress.

Codependency is a type of dysfunctional helping relationship where one person supports or enables another person's drug addiction, alcoholism, gambling addiction, poor mental health, immaturity, irresponsibility, or under-achievement. Among the core characteristics of codependency, the most common theme is an excessive reliance on other people for approval and a sense of identity.

Given its grassroots origin, the precise definition of codependency varies based on the source but can be generally characterized as a subclinical and situational or episodic behavior similar to that of dependent personality disorder. In its broadest definition, a codependent is someone who cannot function from their innate self and whose thinking and behavior is instead organized around another person, or even a process, or substance. In this context, people who are addicted to a substance, like drugs, or a process, like gambling or sex, can also be considered codependent. In its most narrow definition, it requires one person to be physically or psychologically addicted, such as to heroin, and the second person to be psychologically dependent on that behavior. Some users of the codependency concept use the word as an alternative to using the concept of dysfunctional families, without statements that classify it as a disease.

The ICD-10 includes a diagnostic guideline for the wide group of personality and behavioural disorders. However, every disorder has its own diagnostic criteria. In case of the organic personality disorder, patient has to show at least three of the following diagnostic criteria over a six or more months period. organic personality disorder is associated with a large variety of symptoms, such as deficits in cognitive function, dysfunctional behaviours, psychosis, neurosis, emotional changes, alterations in expression function and irritability. Patients with organic personality disorder can present emotional lability that means their emotional expressions are unstable and fluctuating. In addition, patients show reduction in ability of perseverance with their goals and they express disinhibited behaviours, which are characterised by inappropriate sexual and antisocial actions. For instance, patients can show dissocial behaviours, like stealing. Moreover, according to diagnostic guideline of ICD-10, patients can suffer from cognitive disturbances and they present signs of suspiciousness and paranoid ideas. Additionally, patients may present alteration in process of language production that means there are changes in language rate and flow. Furthermore, patients may show changes in their sexual preference and hyposexuality symptoms.

Another common feature of personality of patients with organic personality disorder is their dysfunctional and maladaptive behaviour that causes serious problems in these patients, because they face problems with pursuit and achievement of their goals. It is worth to be mentioned that patients with organic personality disorder express a feeling of unreasonable satisfaction and euphoria. Also, the patients show aggressive behaviours sometimes and these serious dysfunctions in their behaviour can have effects on their life and their relationships with other people. Specifically patients show intense signs of anger and aggression because of their inability to handle their impulses. The type of this aggression is called "impulsive aggression". Furthermore, it is worth to be mentioned that the pattern of organic personality disorder presents some similarities with pattern of temporal lobe epilepsy (TLE). Specifically patients who suffer from this chronic disorder type of epilepsy, express aggressive behaviours, likewise it happens to patients with organic personality disorder. Another similar symptom between Temporal lobe epilepsy and organic personality disorder is the epileptic seizure. The symptom of epileptic seizure has influence on patients' personality that means it causes behavioural alterations". The Temporal lobe epilepsy (TLE) is associated with the hyperexcitability of the medial temporal lobe (MTL) of patients. Finally, patients with organic personality disorder may present similar symptoms with patients, who suffer from the Huntington's disease as well. The symptoms of apathy and irritability are common between these two groups of patients.

Some scholars believe that codependency is not a negative trait, and does not need to be treated, as it is more likely a healthy personality trait taken to excess. Codependency in nonclinical populations has some links with favourable characteristics of family functioning.

Stan Katz states that codependence is over-diagnosed, and that many people who could be helped with shorter-term treatments instead become dependent on long-term self-help programs. The language of, symptoms of, and treatment for codependence derive from the medical model suggesting a disease process underlies the behavior. However, there is no evidence that codependence is caused by a disease process.

In their book, “Attached.”, Dr. Amir Levine and Rachel S. F. Heller, address what they call the “codependency myth” by asserting that attachment theory is a more scientific and helpful model for understanding and dealing with attachment in adults.

There are several subtypes of female sexual arousal disorders. They may indicate onset: lifelong (since birth) or acquired. They may be based on context: they may occur in all situations (generalized) or be situation-specific (situational). For example, the disorder may occur with a spouse but not with a different partner.

The length of time the disorder has existed and the extent to which it is partner- or situation-specific, as opposed to occurring in all situations, may be the result of different causative factors and may influence the treatment for the disorder. It may be due to psychological factors or a combination of factors.

Low frustration tolerance (LFT), or "short-term hedonism" is a concept utilized to describe the inability to tolerate unpleasant feelings or stressful situations. It stems from the feeling that reality should be as wished, and that any frustration should be resolved quickly and easily. People with low frustration tolerance experience emotional disturbance when frustrations are not quickly resolved. Behaviors are then directed towards avoiding frustrating events which, paradoxically, leads to increased frustration and even greater mental stress.

In REBT the opposite construct is "high frustration tolerance".

Treatment by a physician involves assessing parental competence, and whether the parents set limits correctly and consistently. Physicians should rule out dysfunction in the family, referring dysfunctional families for family therapy and dysfunctional parents for parenting skills training, and counsel parents in methods for modifying their child's behavior.

A spoiled child, spoiled brat, or simply a brat is a derogatory term aimed at children who exhibit behavioral problems from being overindulged by their parents. Children and teens who are perceived as spoiled may be described as "overindulged", "grandiose", "narcissistic" or "egocentric-regressed". Perception is important to take into account, because when the child has a neurological condition such as autism, ADHD or intellectual disability, observers may judge them as "spoiled" without understanding the whole picture. There is no accepted scientific definition of what "spoiled" means, and professionals are often unwilling to use the label because it is considered vague and derogatory. Being spoiled is not recognized as a mental disorder in any of the medical manuals, such as the ICD-10 or the DSM-IV, or its successor, the DSM-5.

The frustration discomfort scale (FDS), a multidimensional measure for LFT, was developed using REBT theories.

These dimensions were labelled in four categories:

1. Emotional intolerance, involving intolerance of emotional distress.

2. Entitlement, involving intolerance of unfairness and frustrated gratification.

3. Discomfort intolerance, involving intolerance of difficulties and hassles.

4. Achievement, involving intolerance of frustrated achievement goals.

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.

The current diagnostic criteria for MCDD are a matter of debate due to it not being in the DSM-IV or ICD-10. Various websites contain various diagnostic criteria. At least three of the following categories should be present. Co-occurring clusters of symptoms must also not be better explained by being symptoms of another disorder such as experiencing mood swings due to autism, cognitive difficulties due to schizophrenia, and so on. The exact diagnostic criteria for MCDD remain unclear but may be a useful diagnosis for people who do not fall into any specific category. It could also be argued that MCDD is a vague and unhelpful term for these patients.

Ideational apraxia is a difficult disorder to diagnose. That is because the majority of individuals who have this disorder almost always have some other type of dysfunction such as agnosia or aphasia. The tests used to make an IA diagnosis can range from easy single object tasks to complex multiple object tasks. When being tested a patient may be asked to view twenty objects. They then have to demonstrate the use of each single object following three different ways of presenting the stimuli. The patient must then perform complex test where the examiner describes a task such as making coffee and the patient must show the sequential steps that makes a cup of coffee. The patients are then scored on how many errors are seen by the examiner. The errors of the patients in performing the MOT were scored according to a set of criteria partly derived from De Renzi and Lucchelli.

Two classes of errors are used to develop a diagnosis:

Class I: Sequence errors

- Action addition (AA) is a meaningful action step that is not necessary for accomplishing the goal of the MOT action (e.g., removing the filter of the orange squeezer in order to pour the liquid);

- Action anticipation (A) is an anticipation of an action that would normally be performed later in the action sequence (e.g., blowing the match out before using it);

- Step omission (SO) is an omission of a step of the multiple-actions sequence (e.g., inserting the filter in the coffee machine without pouring some water);

- Perseveration (P) is a repetition of an action step previously performed in the action sequence.

Class II: Conceptual errors

- Misuse (Mis) errors that can be differentiated into two further types:

1. (Mis1) the first type of misuse involves a well-performed action that is appropriate to an object different from the object target (e.g., hammering with a saw);

2. (Mis2) the second type involves an action that is appropriate at a superordinate level to the object at hand but is inappropriately specified at the subordinate level (e.g., cutting an orange with a knife as if it were butter).

- Mislocation (Misl) which can be further differentiated into two error subtypes:

1. (Misl1) the first type is an action that is appropriate to the object in hand but is performed in completely the wrong place (e.g., pouring some liquid from the bottle onto the table rather than into the glass);

2. (Misl2) the second type involves the correct general selection of the target object on which to operate with the source object or instrument in hand but with the exact location of the action being wrong (e.g., striking the match inside the matchbox).

- Tool omission (TO) is an omission in using an obligatory tool where the hand is used instead (e.g., opening a bottle without using a bottle opener);

- Pantomiming (Pant) is where the patient pantomime show the object should be used instead of using it;

- Perplexity (Perpl) Is a delay or hesitation in starting an action or subcomponents of an action;

- Toying(T) consists of a brief but repeated touching of an object or objects on the table.

As the examiner observes the patient for each task they mark off which errors were committed. From this criteria the examiner will be able to focus on severity of the dysfunction. It is important to express that the motor movement is not lost in patients with IA. Yet, at first glance their movements may appear to be awkward because they are unable to plan a sequence of movements with the given object.

The nature of the alleged mental representations that underlie the act of pointing to target body parts have been a controversial issue. Originally, it was diagnosed as the effects of general mental deterioration or of aphasia on the task of pointing to body parts on verbal command. However, contemporary neuropsychological therapy seeks to establish the independence of autotopagnosia from other disorders. With such a general definition, a patient that presents with a dysfunction of or failure in accessing one of four mental representation systems suffers from autotopagnosia. Through observational testing, the type of mental misrepresentation of the body can be deduced: whether "semantic", "visuospatial", "somatosensory", or "motor misrepresentations". Neuropsychological tests can provide a proper diagnosis in regards to the specificity of patient’s agnosic condition.

1) Test 1: Body Part Localization: Free vision and no vision conditions

2) Test 2: On-line positioning of body vis-à-vis objects

3) Test 3: Localization of objects on the body surface

4) Test 4: Body part semantic knowledge

5) Test 5: Matching body parts: Effect of viewing angle

Tactile hallucination is the false perception of tactile sensory input that creates a hallucinatory sensation of physical contact with an imaginary object. It is caused by the faulty integration of the tactile sensory neural signals generated in the spinal cord and the thalamus and sent to the primary somatosensory cortex (SI) and secondary somatosensory cortex (SII). Tactile hallucinations are recurrent symptoms of neurological diseases such as schizophrenia, Parkinson's disease, Ekbom's syndrome and delerium tremens. Patients who experience phantom limb pains also experience a type of tactile hallucination. Tactile hallucinations are also caused by drugs such as cocaine and alcohol.

As autotopagnosia is not a life-threatening condition it is not on the forefront of medical research. Rather, more research is conducted regarding treatments and therapies to alleviate the lesions and traumas that can cause autotopagnosia. Of all the agnosias, visual agnosia is the most common subject of investigation because it is easiest to assess and has the most promise for potential treatments. Most autotopagnosia studies are centered on a few test subjects as part of a group of unaffected or “controlled” participants, or a simple case study. Case studies surrounding a single patient are most common due to the vague nature of the disease.

Indifference to illness may have an adverse impact on a patient's engagement in neurological rehabilitation, cognitive rehabilitation and physical rehabilitation. Patients are not likely to implement rehabilitation for a condition about which they are indifferent. Although anosognosia often resolves in days to weeks after stroke, anosodiaphoria often persists. Therefore, the therapist has to be creative in their rehabilitation approach in order to maintain the interest of the patient.