One of the symptoms of conduct disorder is a lower level of fear. Research performed on the impact of toddlers exposed to fear and distress shows that negative emotionality (fear) predicts toddlers' empathy-related response to distress. The findings support that if a caregiver is able to respond to infant cues, the toddler has a better ability to respond to fear and distress. If a child does not learn how to handle fear or distress the child will be more likely to lash out at other children. If the caregiver is able to provide therapeutic intervention teaching children at risk better empathy skills, the child will have a lower incident level of conduct disorder.

Trichotillomania is classified as compulsive picking of hair of the body. It can be from any place on the body that has hair. This picking results in bald spots. Most people who have mild Trichotillomania can overcome it via concentration and more self-awareness.

Those that suffer from compulsive skin picking have issues with picking, rubbing, digging, or scratching the skin. These activities are usually to get rid of unwanted blemishes or marks on the skin. These compulsions also tend to leave abrasions and irritation on the skin. This can lead to infection or other issues in healing. These acts tend to be prevalent in times of anxiety, boredom, or stress.

Compulsive hoarding in its worst forms can cause fires, unsanitary conditions (such as rat and roach infestations), and other health and safety hazards.

Listed below are possible symptoms hoarders may experience:

- They hold onto a large number of items that most people would consider useless or worthless, such as:

- Junk mail, old catalogs, magazines, and newspapers

- Worn out cooking equipment

- Things that might be useful for making crafts

- Clothes that might be worn one day

- Broken things or trash

- "Freebies" or other promotional products

- Their home is cluttered to the point where many parts are inaccessible and can no longer be used for intended purposes. For example:

- Beds that cannot be slept in

- Kitchens that cannot be used for food preparation

- Tables, chairs, or sofas that cannot be used for dining or sitting

- Unsanitary bathrooms

- Tubs, showers, and sinks filled with items and can no longer be used for washing or bathing.

- Their clutter and mess is at a point where it can cause illness, distress, and impairment. As a result, they:

- Do not allow visitors in, such as family and friends, or repair and maintenance professionals, because the clutter embarrasses them

- Are reluctant or unable to return borrowed items

- Keep the shades drawn so that no one can look inside

- Get into a lot of arguments with family members regarding the clutter

- Are at risk of fire, falling, infestation, or eviction

- Often feel depressed or anxious due to the clutter

Intermittent explosive disorder (sometimes abbreviated as IED) is a behavioral disorder characterized by explosive outbursts of anger and violence, often to the point of rage, that are disproportionate to the situation at hand (e.g., impulsive screaming triggered by relatively inconsequential events). Impulsive aggression is not premeditated, and is defined by a disproportionate reaction to any provocation, real or perceived. Some individuals have reported affective changes prior to an outburst (e.g., tension, mood changes, energy changes, etc.).

The disorder is currently categorized in the "Diagnostic and Statistical Manual of Mental Disorders" (DSM-5) under the "Disruptive, Impulse-Control, and Conduct Disorders" category. The disorder itself is not easily characterized and often exhibits comorbidity with other mood disorders, particularly bipolar disorder. Individuals diagnosed with IED report their outbursts as being brief (lasting less than an hour), with a variety of bodily symptoms (sweating, stuttering, chest tightness, twitching, palpitations) reported by a third of one sample. Aggressive acts are frequently reported accompanied by a sensation of relief and in some cases pleasure, but often followed by later remorse.

For many years, hoarding has been listed as a symptom or a subtype of obsessive-compulsive disorder (OCD) and obsessive–compulsive personality disorder (OCPD). Obsessive-compulsive disorder is a type of anxiety disorder. People with OCD experience unwanted thoughts that incline them to do something repetitively. Some of these behaviors are excessive cleanliness and excessive toothbrushing. The current DSM says that an OCD diagnosis should be considered when:

- The hoarding is driven by fear of contamination or superstitious thoughts

- The hoarding behavior is unwanted or highly distressing

- The individual shows no interest in the hoarded items

- Excessive acquisition is only present if there is a specific obsession with a certain item

Compulsive hoarding does not seem to involve the same neurological mechanisms as more familiar forms of obsessive–compulsive disorder and does not respond to the same drugs, which target serotonin. In compulsive hoarding, the symptoms are presented in the normal stream of consciousness, and are not perceived as repetitive or distressing like in OCD patients. Despite statistics indicating that there is a prevalence of hoarding in 18% to 40% of patients with OCD, only 5% of compulsive hoarders experience symptoms of OCD. In another study, a sample of 217 patients diagnosed with significant hoarding, only 18% were diagnosed with OCD, as opposed to the 36% that were diagnosed with a major depressive disorder. There are significant differences and issues between the diagnostic features of compulsive hoarding and OCD which are being considered in a possible addition to the DSM-V of a new independent disorder such as compulsive hoarding. It is also said that there may be an overlap with a condition known as impulse control disorder (ICD), particularly when compulsive hoarding is linked to compulsive buying or acquisition behavior.

Recent findings suggest that there may be three types of hoarding: pure hoarding, hoarding plus OCD (i.e., co-morbid OCD), and OCD-based hoarding Given the aforementioned distinction, it was proposed to increase coverage of compulsive hoarding in the forthcoming Diagnostic and Statistical Manual of Mental Disorders, fifth edition (DSM-V), both by creating a distinct category for compulsive hoarding, provisionally named, Hoarding Disorder (either in the main manual under "obsessive-compulsive spectrum disorders" or in the appendix), and by including hoarding as a potential symptom of OCD.

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.

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.

The current DSM-5 criteria for Intermittent Explosive Disorder include:

- Recurrent outbursts that demonstrate an inability to control impulses, including either of the following:

- Verbal aggression (tantrums, verbal arguments or fights) or physical aggression that occurs twice in a week-long period for at least three months and does not lead to destruction of property or physical injury (Criterion A1)

- Three outbursts that involve injury or destruction within a year-long period (Criterion A2)

- Aggressive behavior is grossly disproportionate to the magnitude of the psychosocial stressors (Criterion B)

- The outbursts are not premeditated and serve no premeditated purpose (Criterion C)

- The outbursts cause distress or impairment of functioning, or lead to financial or legal consequences (Criterion D)

- The individual must be at least six years old (Criterion E)

- The recurrent outbursts cannot be explained by another mental disorder and are not the result of another medical disorder or substance use (Criterion F)

It is important to note that DSM-5 now includes two separate criteria for types of aggressive outbursts (A1 and A2) which have empirical support:

- Criterion A1: Episodes of verbal and/or non damaging, nondestructive, or non injurious physical assault that occur, on average, twice weekly for three months. These could include temper tantrums, tirades, verbal arguments/fights, or assault without damage. This criterion includes high frequency/low intensity outbursts.

- Criterion A2: More severe destructive/assaultive episodes which are more infrequent and occur, on average, three times within a twelve-month period. These could be destroying an object without regard to value, assaulting an animal or individual. This criterion includes high-intensity/low-frequency outbursts.

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.

Externalizing disorders often involve emotion dysregulation problems and impulsivity that are manifested as antisocial behavior and aggression in opposition to authority, societal norms, and often violate the rights of others. Some examples of externalizing disorder symptoms include, often losing one's temper, excessive verbal aggression, physical aggression to people and animals, destruction of property, theft, and deliberate fire setting. As with all DSM-5 mental disorders, an individual must have functional impairment in at least one domain (e.g., academic, occupational, social relationships, or family functioning) in order to meet diagnostic criteria for an externalizing disorder. Moreover, an individual's symptoms should be atypical for their cultural and environmental context and physical medical conditions should be ruled out before an externalizing disorder diagnosis is considered. Diagnoses must be made by qualified mental health professionals. DSM-5 classifications of externalizing disorders are listed herein, however, can also be used to classify externalizing disorders. More specific criteria and examples of symptoms for various externalizing disorders can be found in the DSM-5.

Conduct disorder (CD) is a mental disorder diagnosed in childhood or adolescence that presents itself through a repetitive and persistent pattern of behavior in which the basic rights of others or major age-appropriate norms are violated. These behaviors are often referred to as "antisocial behaviors." It is often seen as the precursor to antisocial personality disorder, which is per definition not diagnosed until the individual is 18 years old.

Conduct disorder is estimated to affect 51.1 million people globally as of 2013.

There are no specific criteria for "externalizing behavior" or "externalizing disorders." Thus, there is no clear classification of what constitutes an externalizing disorder in the DSM-5. Attention-deficit/hyperactivity disorder (ADHD), oppositional defiant disorder (ODD), conduct disorder (CD), antisocial personality disorder(ASPD), pyromania, kleptomania, intermittent explosive disorder (IED), and substance-related disorders are frequently referred to as externalizing disorders. Disruptive mood dysregulation disorder has also been posited as an externalizing disorder, but little research has examined and validated it to date given its recent addition to the DSM-5, and thus, it is not included further herein.

Kleptomania or klopemania is the inability to refrain from the urge for stealing items and is usually done for reasons other than personal use or financial gain. First described in 1816, kleptomania is classified in psychiatry as an impulse control disorder. Some of the main characteristics of the disorder suggest that kleptomania could be an obsessive-compulsive spectrum disorder.

The disorder is frequently under-diagnosed and is regularly associated with other psychiatric disorders, particularly anxiety and eating disorders, and alcohol and substance abuse. Patients with kleptomania are typically treated with therapies in other areas due to the comorbid grievances rather than issues directly related to kleptomania.

Over the last 100 years, a shift from psychotherapeutic to psychopharmacological interventions for kleptomania has occurred. Pharmacological treatments using selective serotonin reuptake inhibitors (SSRIs), mood stabilizers and opioid receptor antagonists, and other antidepressants along with cognitive behavioral therapy, have yielded positive results.

Some of the fundamental components of kleptomania include recurring intrusive thoughts, impotence to resist the compulsion to engage in stealing, and the release of pressure following the act. These symptoms suggest that kleptomania could be regarded as an obsessive-compulsive type of disorder.

People diagnosed with kleptomania often have other types of disorders involving mood, anxiety, eating, impulse control, and drug use. They also have great levels of stress, guilt, and remorse, and privacy issues accompanying the act of stealing. These signs are considered to either cause or intensify general comorbid disorders. The characteristics of the behaviors associated with stealing could result in other problems as well, which include social segregation and substance abuse. The many types of other disorders frequently occurring along with kleptomania usually make clinical diagnosis uncertain.

There is a difference between ordinary theft and kleptomania: "ordinary theft (whether planned or impulsive) is deliberate and is motivated by the usefulness of the object or its monetary worth," whereas with kleptomania, there "is the recurrent failure to resist impulses to steal items even though the items are not needed for personal use or for their monetary value."

The Diagnostic and Statistical Manual of Mental Disorders revision IV (DSM-IV) describes passive–aggressive personality disorder as a "pervasive pattern of negativistic attitudes and passive resistance to demands for adequate performance in social and occupational situations."

Passive-aggressive behavior is the obligatory symptom of the passive–aggressive personality disorder. Persons with passive–aggressive personality disorder are characterized by procrastination, covert obstructionism, inefficiency and stubbornness.

People with HPD are usually high-functioning, both socially and professionally. They usually have good social skills, despite tending to use them to manipulate others into making them the center of attention. HPD may also affect a person's social and/or romantic relationships, as well as their ability to cope with losses or failures. They may seek treatment for clinical depression when romantic (or other close personal) relationships end.

Individuals with HPD often fail to see their own personal situation realistically, instead dramatizing and exaggerating their difficulties. They may go through frequent job changes, as they become easily bored and may prefer withdrawing from frustration (instead of facing it). Because they tend to crave novelty and excitement, they may place themselves in risky situations. All of these factors may lead to greater risk of developing clinical depression.

Additional characteristics may include:

- Exhibitionist behavior

- Constant seeking of reassurance or approval

- Excessive sensitivity to criticism or disapproval

- Pride of own personality and unwillingness to change, viewing any change as a threat

- Inappropriately seductive appearance or behavior of a sexual nature

- Using somatic symptoms (of physical illness) to garner attention

- A need to be the center of attention

- Low tolerance for frustration or delayed gratification

- Rapidly shifting emotional states that may appear superficial or exaggerated to others

- Tendency to believe that relationships are more intimate than they actually are

- Making rash decisions

- Blaming personal failures or disappointments on others

- Being easily influenced by others, especially those who treat them approvingly

- Being overly dramatic and emotional

Some people with histrionic traits or personality disorder change their seduction technique into a more maternal or paternal style as they age.

Borderline personality disorder may be characterized by the following signs and symptoms:

- Markedly disturbed sense of identity

- Frantic efforts to avoid real or imagined abandonment and extreme reactions to such

- Splitting ("black-and-white" thinking)

- Impulsivity and impulsive or dangerous behaviours

- Intense or uncontrollable emotional reactions that often seem disproportionate to the event or situation

- Unstable and chaotic interpersonal relationships

- Self-damaging behavior

- Distorted self-image

- Dissociation

- Frequently accompanied by depression, anxiety, anger, substance abuse, or rage

The most distinguishing symptoms of BPD are marked sensitivity to rejection or criticism, and intense fear of possible abandonment. Overall, the features of BPD include unusually intense sensitivity in relationships with others, difficulty regulating emotions, and impulsivity. Other symptoms may include feeling unsure of one's personal identity, morals, and values; having paranoid thoughts when feeling stressed; dissociation and depersonalization; and, in moderate to severe cases, stress-induced breaks with reality or psychotic episodes.

The fourth revision of the "Diagnostic and Statistical Manual" (DSM-IV-TR) (now replaced by DSM-5) stated that the child must exhibit four out of the eight signs and symptoms to meet the diagnostic threshold for oppositional defiant disorder. Furthermore, they must be perpetuated for longer than six months and must be considered beyond normal child behavior to fit the diagnosis. Signs and symptoms were: actively refuses to comply with majority's requests or consensus-supported rules; performs actions deliberately to annoy others; is angry and resentful of others; argues often; blames others for their own mistakes; frequently loses temper; is spiteful or seeks revenge; and is touchy or easily annoyed.

These patterns of behavior result in impairment at school and/or other social venues.

A mnemonic that can be used to remember the characteristics of histrionic personality disorder is shortened as "PRAISE ME":

- Provocative (or seductive) behavior

- Relationships are considered more intimate than they actually are

- Attention-seeking

- Influenced easily by others or circumstances

- Speech (style) wants to impress; lacks detail

- Emotional lability; shallowness

- Make-up; physical appearance is used to draw attention to self

- Exaggerated emotions; theatrical

Passive–aggressive personality disorder was listed as an Axis II personality disorder in the DSM-III-R, but was moved in the DSM-IV to Appendix B ("Criteria Sets and Axes Provided for Further Study") because of controversy and the need for further research on how to also categorize the behaviors in a future edition. According to DSM-IV, Passive–aggressive personality disorder is "often overtly ambivalent, wavering indecisively from one course of action to its opposite. They may follow an erratic path that causes endless wrangles with others and disappointment for themselves." Characteristic of these persons is an "intense conflict between dependence on others and the desire for self-assertion." Although exhibiting superficial bravado, their self-confidence is often very poor, and others react to them with hostility and negativity. This diagnosis is not made if the behavior is exhibited during a major depressive episode or can be attributed to dysthymic disorder.

Oppositional defiant disorder (ODD) is defined by the DSM-5 as "a pattern of angry/irritable mood, argumentative/defiant behavior, or vindictiveness". Unlike children with conduct disorder (CD), children with oppositional defiant disorder are not aggressive towards people or animals, do not destroy property, and do not show a pattern of theft or deceit. A diagnosis of ODD is also no longer applicable if the individual is diagnosed with reactive attachment disorder (RAD).

Television addiction is a proposed addiction model associated with maladaptive or compulsive behavior associated with watching television programming. The most recent medical review on this model concluded that pathological television watching behavior may constitute a true behavioral addiction, but indicated that much more research on this topic is needed to demonstrate this. The compulsion can be extremely difficult to control in many cases. The television addiction model has parallels to other forms of behavioral addiction, such as addiction to drugs or gambling, which are also forms of compulsive behavior.

Television addiction is not a diagnosable condition of DSM-IV.

Compulsions and addictions are intertwined and reward is one major distinction between an addiction and a compulsion (as it is experienced in obsessive-compulsive disorder). An addiction is, by definition, a form of compulsion, and both addictions and compulsions involve operant reinforcement; however, in addiction, the desire and motivation to use a substance or engage in a behavior arises because it is rewarding (i.e., the compulsions that occur in addiction develop through positive reinforcement). In contrast, someone who experiences a compulsion as part of obsessive-compulsive disorder may not perceive anything rewarding from acting on the compulsion. Often, it is a way of dealing with the obsessive part of the disorder, resulting in a feeling of relief (i.e., compulsions may also arise through negative reinforcement).

Deep brain stimulation to the nucleus accumbens, a region in the brain involved heavily in addiction and reinforcement learning, has proven to be an effective treatment of obsessive compulsive disorder.

People with BPD may feel emotions with greater ease, depth and for a longer time than others do. A core characteristic of BPD is affective instability, which generally manifests as unusually intense emotional responses to environmental triggers, with a slower return to a baseline emotional state. People with BPD often engage in idealization and devaluation of others, alternating between high positive regard for people and great disappointment in them. In Marsha Linehan's view, the sensitivity, intensity, and duration with which people with BPD feel emotions have both positive and negative effects. People with BPD are often exceptionally enthusiastic, idealistic, joyful, and loving. However, they may feel overwhelmed by negative emotions ("anxiety, depression, guilt/shame, worry, anger, etc."), experiencing intense grief instead of sadness, shame and humiliation instead of mild embarrassment, rage instead of annoyance, and panic instead of nervousness.

People with BPD are also especially sensitive to feelings of rejection, criticism, isolation, and perceived failure. Before learning other coping mechanisms, their efforts to manage or escape from their very negative emotions may lead to emotional isolation, self-injury or suicidal behavior. They are often aware of the intensity of their negative emotional reactions and, since they cannot regulate them, they shut them down entirely. This can be harmful to people with BPD, since negative emotions alert people to the presence of a problematic situation and move them to address it which the person with BPD would normally be aware of only to cause further distress. People with BPD may feel emotional relief after cutting themselves.

While people with BPD feel euphoria (ephemeral or occasional intense joy), they are especially prone to dysphoria (a profound state of unease or dissatisfaction), depression, and/or feelings of mental and emotional distress. Zanarini et al. recognized four categories of dysphoria that are typical of this condition: extreme emotions, destructiveness or self-destructiveness, feeling fragmented or lacking identity, and feelings of victimization. Within these categories, a BPD diagnosis is strongly associated with a combination of three specific states: feeling betrayed, "feeling like hurting myself", and feeling out of control. Since there is great variety in the types of dysphoria experienced by people with BPD, the amplitude of the distress is a helpful indicator of borderline personality disorder. In addition to intense emotions, people with BPD experience emotional "lability"; or in other words, changeability. Although the term emotional lability suggests rapid changes between depression and elation, the mood swings in people with this condition actually fluctuate more frequently between anger and anxiety and between depression and anxiety.

Behavioral addiction is a form of addiction that involves a compulsion to engage in a rewarding non-drug-related behavior – sometimes called a natural reward – despite any negative consequences to the person's physical, mental, social or financial well-being. A gene transcription factor known as ΔFosB has been identified as a necessary common factor involved in both behavioral and drug addictions, which are associated with the same set of neural adaptations in the reward system.