In the absence of a standardized diagnosis system, many popular, informal classification systems or checklists, outside the DSM and ICD, were created out of clinical and parental experience within the field known as attachment therapy. These lists are unvalidated and critics state they are inaccurate, too broadly defined or applied by unqualified persons. Many are found on the websites of attachment therapists. Common elements of these lists such as lying, lack of remorse or conscience and cruelty do not form part of the diagnostic criteria under either DSM-IV-TR or ICD-10. Many children are being diagnosed with RAD because of behavioral problems that are outside the criteria. There is an emphasis within attachment therapy on aggressive behavior as a symptom of what they describe as attachment disorder whereas mainstream theorists view these behaviors as comorbid, externalizing behaviors requiring appropriate assessment and treatment rather than attachment disorders. However, knowledge of attachment relationships can contribute to the cause, maintenance and treatment of externalizing disorders.

The Randolph Attachment Disorder Questionnaire or RADQ is one of the better known of these checklists and is used by attachment therapists and others. The checklist includes 93 discrete behaviours, many of which either overlap with other disorders, like conduct disorder and oppositional defiant disorder, or are not related to attachment difficulties. Critics assert that it is unvalidated and lacks specificity.

The diagnostic complexities of RAD mean that careful diagnostic evaluation by a trained mental health expert with particular expertise in differential diagnosis is considered essential. Several other disorders, such as conduct disorders, oppositional defiant disorder, anxiety disorders, post traumatic stress disorder and social phobia share many symptoms and are often comorbid with or confused with RAD, leading to over and under diagnosis. RAD can also be confused with neuropsychiatric disorders such as autism, pervasive developmental disorder, childhood schizophrenia and some genetic syndromes. Infants with this disorder can be distinguished from those with organic illness by their rapid physical improvement after hospitalization. Autistic children are likely to be of normal size and weight and often exhibit a degree of intellectual disability. They are unlikely to improve upon being removed from the home.

The utility of PTSD derived psychotherapies for assisting children with C-PTSD is uncertain. This area of diagnosis and treatment calls for caution in use of the category C-PTSD. Ford and van der Kolk have suggested that C-PTSD may not be as useful a category for diagnosis and treatment of children as a proposed category of developmental trauma disorder (DTD). For DTD to be diagnosed it requires a

'history of exposure to early life developmentally adverse interpersonal trauma such as sexual abuse, physical abuse, violence, traumatic losses of other significant disruption or betrayal of the child's relationships with primary caregivers, which has been postulated as an etiological basis for complex traumatic stress disorders. Diagnosis, treatment planning and outcome are always relational.'

Since C-PTSD or DTD in children is often caused by chronic maltreatment, neglect or abuse in a care-giving relationship the first element of the biopsychosocial system to address is that relationship. This invariably involves some sort of child protection agency. This both widens the range of support that can be given to the child but also the complexity of the situation, since the agency's statutory legal obligations may then need to be enforced.

A number of practical, therapeutic and ethical principles for assessment and intervention have been developed and explored in the field:

- Identifying and addressing threats to the child's or family's safety and stability are the first priority.

- A relational bridge must be developed to engage, retain and maximize the benefit for the child and caregiver.

- Diagnosis, treatment planning and outcome monitoring are always relational (and) strengths based.

- All phases of treatment should aim to enhance self-regulation competencies.

- Determining with whom, when and how to address traumatic memories.

- Preventing and managing relational discontinuities and psychosocial crises.

The person's appearance, behavior, and history, along with a psychological evaluation, are usually sufficient to establish a diagnosis. There is no test to confirm this diagnosis. Because the criteria are subjective, some people may be wrongly diagnosed.

For a child or adolescent to qualify for a diagnosis of ODD, behaviours must cause considerable distress for the family or interfere significantly with academic or social functioning. Interference might take the form of preventing the child or adolescent from learning at school or making friends, or placing him or her in harmful situations. These behaviours must also persist for at least six months. Effects of ODD can be greatly amplified by other disorders in comorbidity such as ADHD. Other common comorbid disorders include depression and substance use disorders.

There are a variety of mainstream prevention programs and treatment approaches for attachment disorder, attachment problems and moods or behaviors considered to be potential problems within the context of attachment theory. All such approaches for infants and younger children concentrate on increasing the responsiveness and sensitivity of the caregiver, or if that is not possible, changing the caregiver. Such approaches include 'Watch, wait and wonder,' manipulation of sensitive responsiveness, modified 'Interaction Guidance,'. 'Preschool Parent Psychotherapy,'. Circle of Security', Attachment and Biobehavioral Catch-up (ABC), the New Orleans Intervention, and Parent-Child psychotherapy. Other known treatment methods include Developmental, Individual-difference, Relationship-based therapy (DIR) (also referred to as "Floor Time") by Stanley Greenspan, although DIR is primarily directed to treatment of pervasive developmental disorders Some of these approaches, such as that suggested by Dozier, consider the attachment status of the adult caregiver to play an important role in the development of the emotional connection between adult and child. This includes foster parents, as children with poor attachment experiences often do not elicit appropriate caregiver responses from their attachment behaviors despite 'normative' care.

Treatment for reactive attachment disorder for children usually involves a mix of therapy, counseling, and parenting education. These must be designed to make sure the child has a safe environment to live in and to develop positive interactions with caregivers and improves their relationships with their peers.

Medication can be used as a way to treat similar conditions, like depression, anxiety, or hyperactivity; however, there is no quick fix for treating reactive attachment disorder. A pediatrician may recommend a treatment plan. For example, a mix of family therapy, individual psychological counseling, play therapy, special education services and parenting skills classes.

The previous edition of the Diagnostic and Statistical Manual of Mental Disorders, DSM IV-TR, defines histrionic personality disorder (in Cluster B) as:

The DSM-IV requires that a diagnosis for any specific personality disorder also satisfies a set of general personality disorder criteria.

Recognised assessment methods of attachment styles, difficulties or disorders include the Strange Situation procedure (Mary Ainsworth), the separation and reunion procedure and the Preschool Assessment of Attachment ("PAA"), the Observational Record of the Caregiving Environment ("ORCE") and the Attachment Q-sort ("AQ-sort").

More recent research also uses the Disturbances of Attachment Interview or "DAI" developed by Smyke and Zeanah, (1999). This is a semi-structured interview designed to be administered by clinicians to caregivers. It covers 12 items, namely having a discriminated, preferred adult, seeking comfort when distressed, responding to comfort when offered, social and emotional reciprocity, emotional regulation, checking back after venturing away from the care giver, reticence with unfamiliar adults, willingness to go off with relative strangers, self endangering behavior, excessive clinging, vigilance/hypercompliance and role reversal.

Approaches to the treatment of ODD include parent management training, individual psychotherapy, family therapy, cognitive behavioral therapy, and social skills training. According to the American Academy of Child and Adolescent Psychiatry, treatments for ODD are tailored specifically to the individual child, and different treatment techniques are applied for pre-schoolers and adolescents. Several preventative programs have had a positive effect on those at high risk for ODD. Both home visitation and programs such as Head Start have shown some effectiveness in preschool children. Social skills training, parent management training, and anger management programs have been used as prevention programs for school-age children at risk for ODD. For adolescents at risk for ODD, cognitive interventions, vocational training and academic tutoring have shown preventative effectiveness. There is also limited evidence that the atypical antipsychotic medication risperidone decreases aggression and conduct problems in youth with disruptive behavioral disorders, such as ODD.

Not only are there significant health risks associated with compulsive hoarding, but scientists are also trying to pinpoint how significant the interference is with occupational and social functioning in a hoarder's daily life. In a pool of compulsive hoarders, 42% found their behavior problematic to the 63% of their family and friends who saw the behavior as problematic. The findings suggest that individuals who hoard may exhibit impaired sensitivity to their own and others’ emotions, and conversely, relate the world around them by forming attachments to possessions rather than to people. Lower emotional intelligence among hoarding patients may also impact their ability to discard and organize their possessions. With such detrimental characteristics, comprehensive research has been performed to find a cure. Although this is ongoing research, most investigations have found that only a third of patients who hoard show an adequate response to these medications and therapeutic interventions.

With the modifications to the DSM, insurance coverage for treatments will change as well as special education programs.

As noted by Altman, McGoey & Sommer, it is important to observe the child, "in multiple contexts, on numerous occasions, and in their everyday environments (home, daycare, preschool)". It is beneficial to view parent and child interactions and behaviors that may contribute to SAD.

Dyadic Parent-Child Interaction Coding System and recently the Dyadic Parent-Child Interaction Coding System II (DPICS II) are methods used when observing parents and children interactions.

Separation Anxiety Daily Diaries (SADD) have also been used to “assess anxious behaviors along with their antecedents and consequences and may be particularly suited to SAD given its specific focus on parent–child separation” (Silverman & Ollendick, 2005). The diaries are carefully evaluated for validity.

Following the DSM-5 work groups’ recommendation to remove the bereavement-exclusionary criteria, there is some concern that the addition of CGD may increase the possibility of medicalizing the grieving process. However, proponents of CGD claim that with proper clinical assessment only those with abnormally incapacitating levels of grief will receive this diagnosis and benefit from treatment. Furthermore, despite the possibility of diagnosis-related stigma the clinical necessity for treatment is a priority for those suffering from CGD.

At the preschool-aged stage, early identification and intervention is crucial. The communication abilities of young children are taken into consideration when creating age-appropriate assessments.

A commonly used assessment tool for preschool-aged children (ages 2–5) is the Preschool Age Psychiatric Assessment (PAPA). Additional questionnaires and rating scales that are used to assess the younger population include the Achenbach Scales, the Fear Survey Schedule for Infants and Preschoolers, and The Infant–Preschool Scale for Inhibited Behaviors.

Preschool children are also interviewed. Two interviews that are sometimes conducted are Attachment Doll-Play and Emotional Knowledge. In both of the assessments the interviewer depicts a scenario where separation and reunion occur; the child is then told to point at one of the four facial expressions presented. These facial expressions show emotions such as anger or sadness. The results are then analyzed.

Behavioral observations are also utilized when assessing the younger population. Observations enable the clinician to view some of the behaviors and emotions in specific contexts.

Dissociative disorders (DD) are widely believed to have roots in traumatic childhood experience (abuse or loss), but symptomology often goes unrecognized or is misdiagnosed in children and adolescents. There are several reasons why recognizing symptoms of dissociation in children is challenging: it may be difficult for children to describe their internal experiences; caregivers may miss signals or attempt to conceal their own abusive or neglectful behaviors; symptoms can be subtle or fleeting; disturbances of memory, mood, or concentration associated with dissociation may be misinterpreted as symptoms of other disorders.

In addition to developing diagnostic tests for children and adolescents (see above), a number of approaches have been developed to improve recognition and understanding of dissociation in children. Recent research has focused on clarifying the neurological basis of symptoms associated with dissociation by studying neurochemical, functional and structural brain abnormalities that can result from childhood trauma. Others in the field have argued that recognizing disorganized attachment (DA) in children can help alert clinicians to the possibility of dissociative disorders.

Clinicians and researchers also stress the importance of using a developmental model to understand both symptoms and the future course of DDs. In other words, symptoms of dissociation may manifest differently at different stages of child and adolescent development and individuals may be more or less susceptible to developing dissociative symptoms at different ages. Further research into the manifestation of dissociative symptoms and vulnerability throughout development is needed. Related to this developmental approach, more research is required to establish whether a young patient’s recovery will remain stable over time.

Herman believes recovery from C-PTSD occurs in three stages:

1. establishing safety,

2. remembrance and mourning for what was lost,

3. reconnecting with community and more broadly, society.

Herman believes recovery can only occur within a healing relationship and only if the survivor is empowered by that relationship. This healing relationship need not be romantic or sexual in the colloquial sense of "relationship", however, and can also include relationships with friends, co-workers, one's relatives or children, and the therapeutic relationship.

Complex trauma means complex reactions and this leads to complex treatments. Hence, treatment for C-PTSD requires a multi-modal approach. It has been suggested that treatment for C-PTSD should differ from treatment for PTSD by focusing on problems that cause more functional impairment than the PTSD symptoms. These problems include emotional dysregulation, dissociation, and interpersonal problems. Six suggested core components of complex trauma treatment include:

1. Safety

2. Self-regulation

3. Self-reflective information processing

4. Traumatic experiences integration

5. Relational engagement

6. Positive affect enhancement

Multiple treatments have been suggested for C-PTSD. Among these treatments are experiential and emotionally focused therapy, internal family systems therapy, sensorimotor psychotherapy, eye movement desensitization and reprocessing therapy (EMDR), dialectical behavior therapy (DBT), cognitive behavioral therapy, psychodynamic therapy, family systems therapy and group therapy.

Although the DSM-5 work groups have suggested using "adjustment disorder, specified as bereavement-related" to diagnose complicated grief, opposing opinions contend that this does not fit the nature of CGD and is an inappropriate diagnosis for those suffering from CGD.

Data from the 2001–02 National Epidemiologic Survey on Alcohol and Related Conditions indicates a prevalence rate of 2.36% in the American general population. It appears to occur with equal frequency in males and females. In one study, it was seen in 14.7% of psychiatric outpatients.

The lifetime prevalence of dissociative disorders varies from 10% in the general population to 46% in psychiatric inpatients. Diagnosis can be made with the help of structured interviews such as the Dissociative Disorders Interview Schedule (DDIS) and the Structured Clinical Interview for DSM-IV Dissociative Disorders (SCID-D), or with the Dissociative Experiences Scale (DES) which is a self-assessment questionnaire. Some diagnostic tests have also been adapted and/or developed for use with children and adolescents such as the Children's Version of the Response Evaluation Measure (REM-Y-71), Child Interview for Subjective Dissociative Experiences, Child Dissociative Checklist (CDC), Child Behavior Checklist (CBCL) Dissociation Subscale, and the Trauma Symptom Checklist for Children Dissociation Subscale.

There are problems with classification, diagnosis and therapeutic strategies of dissociative and conversion disorders which can be understood by the historic context of hysteria. Even current systems used to diagnose DD such as the DSM-IV and ICD-10 differ in the way the classification is determined. In most cases mental health professionals are still hesitant to diagnose patients with Dissociative Disorder, because before they are considered to be diagnosed with Dissociative Disorder these patients have more than likely been diagnosed with major depression, anxiety disorder, and most often post-traumatic disorder.

An important concern in the diagnosis of dissociative disorders is the possibility that the patient may be feigning symptoms in order to escape negative consequences. Young criminal offenders report much higher levels of dissociative disorders, such as amnesia. In one study it was found that 1% of young offenders reported complete amnesia for a violent crime, while 19% claimed partial amnesia. There have also been incidences in which people with dissociative identity disorder provide conflicting testimonies in court, depending on the personality that is present.

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.

According to Michael First of the DSM-5 working committee the focus of a relational disorder, in contrast to other DSM-IV disorders, "is on the relationship rather than on any one individual in the relationship".

Relational disorders involve two or more individuals and a disordered "juncture", whereas typical Axis I psychopathology describes a disorder at the individual level. An additional criterion for a relational disorder is that the disorder cannot be due solely to a problem in one member of the relationship, but requires pathological interaction from each of the individuals involved in the relationship.

For example, if a parent is withdrawn from one child but not another, the could be attributed to a relational disorder. In contrast, if a parent is withdrawn from both children, the dysfunction may be more appropriately attributable to a disorder at the individual level.

First states that "relational disorders share many elements in common with other disorders: there are distinctive features for classification; they can cause clinically significant impairment; there are recognizable clinical courses and patterns of comorbidity; they respond to specific treatments; and they can be prevented with early interventions. Specific tasks in a proposed research agenda: develop assessment modules; determine the clinical utility of relational disorders; determine the role of relational disorders in the etiology and maintenance of individual disorders; and consider aspects of relational disorders that might be modulated by individual disorders."

The proposed new diagnosis defines a relational disorder as "persistent and painful patterns of feelings, behaviors, and perceptions" among two or more people in an important personal relationship, such a husband and wife, or a parent and children.

According to psychiatrist Darrel Regier, MD, some psychiatrists and other therapists involved in couples and marital counseling have recommended that the new diagnosis be considered for possible incorporation into the Diagnostic and Statistical Manual of Mental Disorders (DSM IV).

Certain children who are particularly attached to their mother or other family figure due to separation anxiety and/or attachment theory often suffer the onset early, in pre-school, crèche or before school starts.

School phobia is diagnosed primarily through questionnaires and interviews with doctors. Other methods like observation have not proven to be as useful. This is partly because (school) anxiety is an internal phenomenon. An example of a modern multidimensional questionnaire is the "Differential Power Anxiety Inventory 'approach, with twelve scales to diagnose four different areas: anxiety-inducing conditions, manifestations, coping strategies and stabilization forms."

- Cognitive and lifestyle exploration

- 'School Phobia Test' (SAT)

- 'Anxiety questionnaire for students', (AFS)

Research on parent–child abuse bears similarities to that on marital violence, with the defining characteristic of the disorder being physical aggression by a parent toward a child. The disorder is frequently concealed by parent and child, but may come to the attention of the clinician in several ways, from emergency room medical staff to reports from child protection services.

Some features of abusive parent–child relationships that serve as a starting point for classification include: (a) the parent is physically aggressive with a child, often producing physical injury, (b) parent–child interaction is coercive, and parents are quick to react to provocations with aggressive responses, and children often reciprocate aggression, (c) parents do not respond effectively to positive or prosocial behavior in the child, (d) parents do not engage in discussion about emotions, (e) parent engages in deficient play behavior, ignores the child, rarely initiates play, and does little teaching, (f) children are insecurely attached and, where mothers have a history of physical abuse, show distinctive patterns of disorganized attachment, and (g) parents relationship shows coercive marital interaction patterns.

Defining the relational aspects of these disorders can have important consequences. For example, in the case of early appearing feeding disorders, attention to relational problems may help delineate different types of clinical problems within an otherwise broad category. In the case of conduct disorder, the relational problems may be so central to the maintenance, if not the etiology, of the disorder that effective treatment may be impossible without recognizing and delineating it.

Emotional dysregulation (ED) is a term used in the mental health community to refer to an emotional response that is poorly modulated, and does not fall within the conventionally accepted range of emotive response.

Possible manifestations of emotional dysregulation include angry outbursts or behavior outbursts such as destroying or throwing objects, aggression towards self or others, and threats to kill oneself. These variations usually occur in seconds to minutes or hours. Emotional dysregulation can lead to behavioral problems and can interfere with a person's social interactions and relationships at home, in school, or at place of employment.

Emotional dysregulation can be associated with an experience of early psychological trauma, brain injury, or chronic maltreatment (such as child abuse, child neglect, or institutional neglect/abuse), and associated disorders such as reactive attachment disorder. Emotional dysregulation may present in people with psychiatric disorders such as attention deficit hyperactivity disorder, bipolar disorder, borderline personality disorder, narcissistic personality disorder, and complex post-traumatic stress disorder. ED is also found among those with autism spectrum disorders. In such cases as borderline personality disorder, hypersensitivity to emotional stimuli causes a slower return to a normal emotional state. This is manifested biologically by deficits in the frontal cortices of the brain.

Cognitive-behavioral therapy (CBT) is a commonly implemented therapeutic intervention for compulsive hoarding. As part of cognitive behavior therapy, the therapist may help the patient to:

- Discover why he or she is compelled to hoard.

- Learn to organize possessions in order to decide what to discard.

- Develop decision-making skills.

- Declutter the home during in-home visits by a therapist or professional organizer.

- Gain and perform relaxation skills.

- Attend family and/or group therapy.

- Be open to trying psychiatric hospitalization if the hoarding is serious.

- Have periodic visits and consultations to keep a healthy lifestyle.

This modality of treatment usually involves exposure and response prevention to situations that cause anxiety and cognitive restructuring of beliefs related to hoarding. Furthermore, research has also shown that certain CBT protocols have been more effective in treatment than others. CBT programs that specifically address the motivation of the sufferer, organization, acquiring new clutter, and removing current clutter from the home have shown promising results. This type of treatment typically involves in-home work with a therapist combined with between-session homework, the completion of which is associated with better treatment outcomes. Research on Internet-based CBT treatments for the disorder (where participants have access to educational resources, cognitive strategies, and chat groups) has also shown promising results both in terms of short- and long-term recovery.

Other therapeutic approaches that have been found to be helpful are:

1. Motivational interviewing: originated in addiction therapy. This method is significantly helpful when used in hoarding cases in which insight is poor and ambivalence around change is marked.

2. Harm reduction rather than symptom reduction: also borrowed from addiction therapy. The goal is to decrease the harmful implications of the behavior, rather than the hoarding behaviors.

3. Group therapy: reduces social isolation and social anxiety and is cost-effective compared to one-on-one intervention.

4. Eye movement desensitization and reprocessing (EMDR) has been employed, although there is insufficient evidence for EMDR to be considered effective for treating compulsive hoarding (as for treating obsessive-compulsive disorders in general).

Individuals with hoarding behaviors are often described as having low motivation and poor compliance levels, and as being indecisive and procrastinators, which may frequently lead to premature termination (i.e., dropout) or low response to treatment. Therefore, it was suggested that future treatment approaches, and pharmacotherapy in particular, be directed to address the underlying mechanisms of cognitive impairments demonstrated by individuals with hoarding symptoms.

Mental health professionals frequently express frustration regarding hoarding cases, mostly due to premature termination and poor response to treatment. Patients are frequently described as indecisive, procrastinators, recalcitrant, and as having low or no motivation, which can explain why many interventions fail to accomplish significant results. To overcome this obstacle, some clinicians recommend accompanying individual therapy with home visits to help the clinician:

Likewise, certain cases are assisted by professional organizers as well.

Early experiences with caregivers can lead to differences in emotional regulation. The responsiveness of a caregiver to an infant's signals can help an infant regulate their emotional systems. Caregiver interaction styles that overwhelm a child or that are unpredictable may undermine emotional regulation development. Effective strategies involve working with a child to support developing self-control such as modeling a desired behavior rather than demanding it.

The richness of environment that a child is exposed to helps development of emotional regulation. An environment must provide appropriate levels of freedom and constraint. The environment must allow opportunities for a child to practice self-regulation. An environment with opportunities to practice social skills without over-stimulation or excessive frustration helps a child develop self-regulation skills.