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.

About 25-40% of youths diagnosed with conduct disorder qualify for a diagnosis of antisocial personality disorder when they reach adulthood. For those that do not develop ASPD, most still exhibit social dysfunction in adult life.

Conduct disorder is classified in the fourth edition of "Diagnostic and Statistical Manual of Mental Disorders" (DSM). It is diagnosed based on a prolonged pattern of antisocial behaviour such as serious violation of laws and social norms and rules in people younger than the age of 18. Similar criteria are used in those over the age of 18 for the diagnosis of antisocial personality disorder. No proposed revisions for the main criteria of conduct disorder exist in the "DSM-5"; there is a recommendation by the work group to add an additional specifier for callous and unemotional traits. According to DSM-5 criteria for conduct disorder, there are four categories that could be present in the child's behavior: aggression to people and animals, destruction of property, deceitfulness or theft, and serious violation of rules.

Almost all adolescents who have a substance use disorder have conduct disorder-like traits, but after successful treatment of the substance use disorder, about half of these adolescents no longer display conduct disorder-like symptoms. Therefore, it is important to exclude a substance-induced cause and instead address the substance use disorder prior to making a psychiatric diagnosis of conduct disorder.

The past DSM-IV criteria for IED were similar to the current criteria, however verbal aggression was not considered as part of the diagnostic criteria. The DSM-IV diagnosis was characterized by the occurrence of discrete episodes of failure to resist aggressive impulses that result in violent assault or destruction of property. Additionally, the degree of aggressiveness expressed during an episode should be grossly disproportionate to provocation or precipitating psychosocial stressor, and, as previously stated, diagnosis is made when certain other mental disorders have been ruled out, e.g., a head injury, Alzheimer's disease, etc., or due to substance abuse or medication. Diagnosis is made using a psychiatric interview to affective and behavioral symptoms to the criteria listed in the DSM-IV.

The DSM-IV-TR was very specific in its definition of Intermittent Explosive Disorder which was defined, essentially, by exclusion of other conditions. The diagnosis required:

1. several episodes of impulsive behavior that result in serious damage to either persons or property, wherein

2. the degree of the aggressiveness is grossly disproportionate to the circumstances or provocation, and

3. the episodic violence cannot be better accounted for by another mental or physical medical condition.

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.

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.

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.

Diagnosis of borderline personality disorder is based on a clinical assessment by a mental health professional. The best method is to present the criteria of the disorder to a person and to ask them if they feel that these characteristics accurately describe them. Actively involving people with BPD in determining their diagnosis can help them become more willing to accept it. Although some clinicians prefer not to tell people with BPD what their diagnosis is, either from concern about the stigma attached to this condition or because BPD used to be considered untreatable, it is usually helpful for the person with BPD to know their diagnosis. This helps them know that others have had similar experiences and can point them toward effective treatments.

In general, the psychological evaluation includes asking the patient about the beginning and severity of symptoms, as well as other questions about how symptoms impact the patient's quality of life. Issues of particular note are suicidal ideations, experiences with self-harm, and thoughts about harming others. Diagnosis is based both on the person's report of their symptoms and on the clinician's own observations. Additional tests for BPD can include a physical exam and laboratory tests to rule out other possible triggers for symptoms, such as thyroid conditions or substance abuse. The ICD-10 manual refers to the disorder as "emotionally unstable personality disorder" and has similar diagnostic criteria. In the DSM-5, the name of the disorder remains the same as in the previous editions.

Many psychiatric disorders and some substance use disorders are associated with increased aggression and are frequently comorbid with IED, often making differential diagnosis difficult. Individuals with IED are, on average, four times more likely to develop depressive or anxiety disorders, and three times more likely to develop substance use disorders.

Bipolar disorder has been linked to increased agitation and aggressive behavior in some individuals, but for these individuals aggressiveness is limited to manic and/or depressive episodes, whereas individuals with IED experience aggressive behavior even during periods with a neutral or positive mood. In one clinical study, the two disorders co-occurred 60% of the time. Patients report manic-like symptoms occurring just before outbursts and continuing throughout. According to a study, the average onset age of IED was around five years earlier than the onset age of bipolar disorder, indicating a possible correlation between the two.

Similarly, alcohol and other substance use disorders may exhibit increased aggressiveness, but unless this aggression is experienced outside of periods of acute intoxication and withdrawal, no diagnosis of IED is given. For chronic disorders, such as PTSD, it is important to assess whether the level of aggression met IED criteria prior to the development of another disorder. In antisocial personality disorder, interpersonal aggression is usually instrumental in nature (i.e., motivated by tangible rewards), whereas IED is more of an impulsive, unpremeditated reaction to situational stress.

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.

ASPD commonly coexists with the following conditions:

When combined with alcoholism, people may show frontal function deficits on neuropsychological tests greater than those associated with each condition.

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.

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.

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.

The Diagnostic and Statistical Manual of Mental Disorders fifth edition (DSM-5) has removed the multiaxial system. Consequently, all disorders, including personality disorders, are listed in Section II of the manual. A person must meet 5 of 9 criteria to receive a diagnosis of borderline personality disorder. The DSM-5 defines the main features of BPD as a pervasive pattern of instability in interpersonal relationships, self image, and affect, as well as markedly impulsive behavior. In addition, the DSM-5 proposes alternative diagnostic criteria for borderline personality disorder in section III, "Alternative DSM-5 Model for Personality Disorders." These alternative criteria are based on trait research and include specifying at least four of seven maladaptive traits. According to Marsha Linehan, many mental health professionals find it challenging to diagnose BPD using the DSM criteria, since these criteria describe such a wide variety of behaviors. To address this issue, Linehan has grouped the symptoms of BPD under five main areas of dysregulation: emotions, behavior, interpersonal relationships, sense of self, and cognition.

ADHD often precedes the onset of ODD, and approximately half of children with ADHD, Combined Type also have ODD. ODD is a risk factor for CD and frequently precedes the onset of CD symptoms. Children with an early onset of CD symptoms, with at least one symptom before age 10 years, are at risk for more severe and persistent antisocial behavior continuing into adulthood. Youth with early-onset conduct problems are particularly at risk for ASPD (note that an onset of CD prior to age 15 is part of the diagnostic criteria for ASPD), whereas CD is typically limited to adolescence when youth's CD symptoms begin during adolescence.

Compulsive talking goes beyond the bounds of what is considered to be a socially acceptable amount of talking. The two main factors in determining if someone is a compulsive talker are talking in a continuous manner, only stopping when the other person starts talking, and others perceiving their talking as a problem. Personality traits that have been positively linked to this compulsion include assertiveness, willingness to communicate, self-perceived communication competence, and neuroticism. Studies have shown that most people who are talkaholics are aware of the amount of talking they do, are unable to stop, and do not see it as a problem.

An addictive behavior is a behavior, or a stimulus related to a behavior (e.g., sex or food), that is both rewarding and reinforcing, and is associated with the development of an addiction. Addictions involving addictive behaviors are normally referred to as behavioral addictions.

Compulsive decluttering is a pattern of behavior that is characterized by an excessive desire to discard objects in one's home and living areas. Other terms for such behavior includes obsessive compulsive spartanism. The homes of compulsive declutterers are often empty. It is the antonym of compulsive hoarding.

When treating addictive personalities, the primary or presenting addiction needs to be treated first. Only once the behavior is under control can the person truly begin to do any of the therapeutic work necessary for recovery.

Common forms of treatment for addictive personalities include cognitive behavioral therapy, as well as other behavioral approaches. These treatments help patients by providing healthy coping skills training, relapse prevention, behavior interventions, family and group therapy, facilitated self-change approaches, and aversion therapy. Behavioral approaches include using positive reinforcement and behavioral modeling. Along with these, other options that help with treating those who suffer with addictive personality include social support, help with goal direction, rewards, enhancing self-efficacy and help teaching coping skills.

Another important skill to learn in treatment, which can be overlooked, is self-soothing. People with addictive personalities use their addictions as coping mechanisms when in stressful situations. However, since their addictions do not actually soothe them, so much as they provide momentary relief from anxiety or uncomfortable emotions, these individuals feel the need to use their addiction more often. Thus, self-soothing and other mindfulness-based interventions can be used for treatment because they provide healthier coping mechanisms once the addictive behavior has been removed. These strategies relate to the use of dialectical behavior therapy, another useful technique. DBT provides ways to tolerate distress and regulate emotions, both of which are challenging to someone with an addictive personality. DBT may not be the most effective treatment for all substance abusers, but there is evidence that it is helpful for most alcoholics and addicts, as well as in eating disorders, and those with co-occurring conditions.

Another form of treatment that has been considered for people with addictive personalities who tend towards substance abuse is medication. A medication called Disulfiram was created in 1947. This pill was used for alcoholics and would cause adverse effects if combined with alcohol. This medication is still used today but two others have been made to help treat alcohol dependence (Acamprosate and Naltrexone). Along with alcohol addictions, Naltrexone is also used for opioid addiction.

Although these medications have proven results in decreasing heavy drinking, doctors still have to consider the patients' health and the risky side effects when prescribing these medications.

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.

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."

The phenomenological similarity and the suggested common basic biological dynamics of kleptomania and OCD, pathological gambling and trichotillomania gave rise to the theory that the similar groups of medications could be used in all these conditions. Consequently, the primary use of selective serotonin reuptake inhibitor (SSRI) group, which is a form of antidepressant, has been used in kleptomania and other impulse control disorders such as binge eating and OCD. Electroconvulsive therapy (ECT), lithium and valproic acid (sodium valproate) have been used as well.

The SSRI's usage is due to the assumption that the biological dynamics of these conditions derives from low levels of serotonin in brain synapses, and that the efficacy of this type of therapy will be relevant to kleptomania and to other comorbid conditions.

Opioid receptor antagonists are regarded as practical in lessening urge-related symptoms, which is a central part of impulse control disorders; for this reason, they are used in treatment of substance abuse. This quality makes them helpful in treating kleptomania and impulse control disorders in general. The most frequently used drug is naltrexone, a long-acting competitive antagonist. Naltrexone acts mainly at μ-receptors, but also antagonises κ- and λ-receptors.

There have been no controlled studies of the psycho-pharmacological treatment of kleptomania. This could be as a consequence of kleptomania being a rare phenomenon and the difficulty in achieving a large enough sample. Facts about this issue come largely from case reports or from bits and pieces gathered from a comparatively small number of cases enclosed in a group series.

Compulsive behavior is defined as performing an act persistently and repetitively without it necessarily leading to an actual reward or pleasure. Compulsive behaviors could be an attempt to make obsessions go away. The act is usually a small, restricted and repetitive behavior, yet not disturbing in a pathological way. Compulsive behaviors are a need to reduce apprehension caused by internal feelings a person wants to abstain from or control. A major cause of the compulsive behaviors is said to be obsessive–compulsive disorder (OCD). "The main idea of compulsive behavior is that the likely excessive activity is not connected to the purpose to which it appears directed." Furthermore, there are many different types of compulsive behaviors including, shopping, hoarding, eating, gambling, trichotillomania and picking skin, checking, counting, washing, sex, and more. Also, there are cultural examples of compulsive behavior.

Although not necessary for the diagnosis, individuals with intellectual disability are at higher risk for SMD. It is more common in boys, and can occur at any age.