# Introduction to Psychology/Psychological Disorders
## A short note on the purpose of this section

This section is intended as a Psychology 101 level introduction to mental disorders. For a more complete course of study, go to the PSY 2065 section.
* Criteria for defining psychological disorders depend on whether cultural norms are violated, whether behavior is maladaptive or harmful, and whether there is distress. • The medical model describes and explains psychological disorders as if they are diseases. • The vulnerability-stress model states that disorders are caused by an interaction between biological and environmental factors. • The learning model theorizes that psychological disorders result from the reinforcement of abnormal behavior. • The psychodynamic model states that psychological disorders result from maladaptive defenses against unconscious conflicts. • Psychologists use objective and projective tests to assess psychological disorders.

## What Is Abnormal?

Abnormal Psychology is the study of psychological differences from the norm. Usually this means disorders, but also includes mental deviances that are still considered unusual, but do not seriously affect a person's functioning. A disorder is defined as a mental trait or other facet of mental functioning that occurs in the minority of the population and is detrimental to the well being of the self or of others.
See: Criticisms of Psychology for some critiques of this concept.

## The diagnostic systems
### What is the diagnostic systems?

Among the mental health professions (marriage and family therapy, clinical social work, professional counseling, psychology, and psychiatry) different diagnostic systems are used. The DSM (Diagnostic and Statistical Manual of Mental Disorders) is used in the USA. It is issued by the American Psychiatric Association (APA). Outside the USA the most used system is the ICD (International Classification of Diseases ). This is issued by the World Health Organization (WHO).
The current editions of the systems are DSM-V and ICD 10.

### Types of Disorders
#### Disorders Diagnosed in Early Childhood

This category of disorders includes disorders that are usually diagnosed in infancy or childhood.

#### ADHD

ADHD in children
ADHD (attention deficit hyperactivity disorder) is a psychological complaint that usually starts in early childhood. As with many other disturbances, it has been more than a challenge to diagnose the prevalence of ADHD and it is estimated that three to ten percent of children show symptoms of hyperactivity, impulsivity or inattentiveness (Nair, 2006). It is evident that boys are more than twice as likely to be affected, than girls (Knölker, 2003). ADHD does not have a single cause, it is a medical disturbance, affecting several areas of the brain, especially the frontal part which is responsible for executive functioning that controls regulation of behavior, working, learning, planning and organizing. Currently it has a multifactoral and integrative clinical picture which includes genetic predispositions, neurobiological, psychological, as well as psychosocial and environmental factors, which are especially important concerning the progression of the disorder (Schneider, 2009). The DSM-IV currently states three different subtypes of the disorder. First, the attention-deficit/hyperactivity disorder predominantly inattentive type where the patient suffers from six or more of the inattentive symptoms but less than six of the symptoms of hyperactivity for at least six months. Second, the predominantly hyperactive-impulsive type, where the patient suffers from at least six symptoms of the hyperactivity and impulsivity scale but less than six on the inattentive scale for at least six months. Finally, the combined type, which is a combination of at least six symptoms on both scales and persisting for at least six months (Michael B. First, Allen Frances, & and Harold Alan Pincus, M.D., 2002).
Symptoms of the inattentive type
* Difficulty paying attention in school or in general. Produced work is often chaotic and filled with careless mistakes
* Rapidly distracted by all kinds of trivial stimuli, noises or people
* Difficulty paying attention to one task or activity at a time
* Trouble finishing and concentrating on everyday tasks that require concentration and time management like homework, paperwork or other duties
* Frequently drifting from one unfinished task to another
* Procrastination
* Disorganized work manner
* Forgetfulness in daily activities
* Inability to complete tasks such as homework or other assignments
* Frequent drifts, not being able to be present and follow the conversation and not grasping the details or rules when it comes to activities in social situations
Symptoms of the hyperactive type
* Squirming and Fidgeting when seated
* Frequent aimless running and walking
* In teens, being restless and in children running, climbing and squirming when it is not appropriate
* Having difficulty engaging in any quiet or calm activity
* Always being on the go
* Excessive and pointless talking
(Michael B. First, Allen Frances, & and Harold Alan Pincus, M.D., 2002).
Causes
It has been found that about 50 percent of affected individuals suffer from a genetic dysfunction of the neuronal communication in the brain (Nadder, 1998). This is especially the case for the neuronal circuit that is responsible for motivation, cognition, emotions and motor behavior which includes the frontal lobe and the striatum. It is mostly acquired genetically, but prenatal complications during child delivery, pollutants, decreased birth weight, infections and deprivation or ailment of the central nervous system can also be possible risk factors. Research also confirmed a lack of dopamine or lower levels of receptors and transporters in the accumbens and midbrain. Additionally, prenatal conditions like cigarette smoking and alcohol consumption have been related (Bush, 2005).
Treatment
ADHD can be classified in three levels of severity. Individuals, who are less severely affected, but have the genetic predisposition for the disorder and do not necessarily need treatment. Visible symptoms might include less inhibition and slight difficulties to concentrate. Individuals, who are more severely affected, need treatment. They might be more likely to suffer from comorbid disorders (e.g. depression, anxiety etc.), suicidal thoughts and are more prone to difficulties in school and loss of employment. However they usually do not have any social malfunctions or disruptive behavior. The severe affected individuals depend on treatment, their behavior is socially disruptive and they are at much greater risk for developing substance abuse or criminal tendencies. It has been found that the two most important aspects of development of the disorder are the age when it is detected, and the way the social surrounding reacts to it, up until to the point of diagnosis. With an extensive prophylaxis and the education of the patients social environment, it is possible to attenuate the symptoms (Lauth, 2002). A treatment-plan could for instance include some of the following (coaching, psychotherapy, cognitive therapy, psychoeducation, psychosocial intervention, pharmacology). However, the attenuation can only go as far as the synaptic and cortical plasticity of the brain, because the seriousness of ADHD mostly depends on neurobiological aspects. In this regard, it is crucial to approach the treatment in a multimodal way. The patients' potentials should be detected and expanded, improvement of social skills and the treatment of possible comorbid disorders should be important aspects (Deutscher Ärzte Verlag, 2003).
Medication
Medications that are commonly used to treat ADHD since the 1950´s are stimulants, which include methylphenidates and amphetamines. Non-stimulant drugs like atomoxetine are also available as alternative (Wigal, 2009). Stimulants have various side-effects, the most common ones include insomnia, euphoria, increased locomotion, restlessness, loss of appetite, psychosis, dependence, increased heart rate and blood pressure. Long-term side effects on the other hand have not been sufficiently established yet. The most common and known methylphenidate is Ritalin. Ritalin belongs to the immediate release tablets, together with Ritalina, Rilatine, Attenta, Methylin, Penid, and Rubifen. Their most important characteristic is that the majority of the beads are released immediately after intake and a small amount of beads are released again about five hours after intake. The other type of methylphenidates are sustained release tablets, namely Concerta, Metadate CD, Methylin ER, Ritalin LA, and Ritalin-SR. These tablets have an immediate release of approximately 30 percent or even less and the rest is evenly distributed 10-12 hours after intake. This guarantees a much longer effect (Green List: Annex to the annual statistical report on psychotropic substances 2003). Another type of medication includes amphetamines like Adderall, which are also used for the treatment of ADHD and work similar as cocaine, but last longer. The effects on the central nervous system are diverse and independent of each other. They can be divided into three classes: psychoanaleptic, hallucinogenic and empathogenic. Just like methylphenidate, amphetamines increase norepinephrine and dopamine in the brain. When amphetamines are active, the concentration of neurotransmitters in the synaptic cleft increases (Robertson, 2009).
Culture and Society
The use and general perspective people have about stimulants differs from country to country. In the United States the medication is prescribed very fast and easily, however, in other countries, like the UK or Germany, it is very difficult and sometimes even illegal for adults to obtain them and is meant for very severe cases only (King, 2006). During authorization of the last Diagnostic and Statistical Manual of Mental Disorders (DSM) it was brought to light that some of the authors of the ADHD related chapters were paid by the pharmaceutical industry to write a rather subjective and brought diagnosis of ADHD. The goal was to make more children fit the criteria of the disorder and to substantially increase profits. For this reason, the authors that will publish the DSM-V in 2012 are obliged to disclose their income and are not allowed to earn more than 10000 US Dollar per year for manual embrace (Center for Science in the Public Interest 2008), (The New York Times 2008).
ADHD in adults
Children who have been diagnosed with ADHD in the United States are known to be less likely to graduate from high school, obtain a college degree and have higher chances of various negative life outcomes like being involved in car crashes, teen pregnancy, substance abuse etc. (Molina, 2009). The stigmatization of people and especially of peers with mental illness is common and has been a great problem in society. Mental illnesses can be unapparent like in the case of depression, or they can be obvious, like in the case of ADHD. High comorbidity of ADHD is responsible that patients are commonly mistreated for other mental illnesses like for instance depression. A study by Fischer revealed that mental health care professionals might still not be adequately capable of diagnosing ADHD and that they ought to take the presence of comorbid major depressive disorder (MDD) as a warning for potential ADHD (Fischer,2007). The severity of ADHD in childhood predicts the likely outcome of the illness in adulthood. It became evident that around four percent of adult population suffers from it, and that this subgroup attracts numerous negative life outcomes e.g. lower academic and professional performance, higher divorce rates and lower socioeconomic status (Kessler, Chiu, Demler, & Walters, 2005). Of those four percent overall affected, 80 percent present comorbid problems, and are often misdiagnosed with malfunctions like conduct disorder, oppositional defiant disorder, antisocial personality disorder, substance abuse, anxiety disorders and most commonly MDD (Biederman, Faraone, Spencer, & Wilens, 1993; Downey, Stelson, Pomerleau, & Giordani, 1997). A subsequent study by Kessler found out that the majority of adults in the United States who suffer from ADHD remain untreated, even though they seek therapeutic help for many other comorbid disorders (Kessler et al, 2006).

## Tic Disorders
### Tourette's Syndrome

Tourette's Syndrome (TS) is a disorder characterized by the presence of at least two tics, one motor and one physical. The vocal tic is, however, more critical to the diagnosis of Tourette's. Tourette's syndrome sufferers usually have faster reflexes than other people. Tourette's syndrome sufferers have a roughly 40% occurrence rate of involuntary swearing, known as coprolalia. This relatively rare symptom has been abused by the media and is a source of much misunderstanding about TS. Tourette's syndrome is also featured in a number of movies, such as 'What about Bob?', in which Bob, the main character, pretends to have Tourette's.

## Anxiety Disorders
### Phobias

Phobias are fears of a specific object or situation. Most phobias have a heritable basis- identical twins separated at birth often develop the same phobia, regardless of environment. Other evidence for the heritable argument is that many phobias are logical when the human ancestors are considered. It makes sense that natural selection would favor genes that caused our ancestors to fear natural dangers like snakes, spiders, and other poisonous animals. Strong memories of situations may also create a phobia. For example, if a person was placed in a tight space as a toddler and nearly suffocated, a life-long fear of closed spaces may follow (claustrophobia).

### Panic Attacks

Panic Disorder is characterized by a series of panic attacks. A panic attack is an inappropriate intense feeling of fear or discomfort including many of the following symptoms: heart palpitations, trembling, shortness of breath, chest pain, dizziness. These symptoms are so severe that the person may actually believe he or she is having a heart attack. In fact, many, if not most of the diagnoses of Panic Disorder are made by a physician in a hospital emergency room.

### Obsessive Compulsive Disorder

Obsessive Compulsive Disorder is an anxiety disorder characterized by the presence of two things: Obsessions and Compulsions. Obsessions are defined as recurring or persistent thoughts, images, or actions that significantly interfere with a person's day-to-day functioning. Some common obsessions are cleanliness, symmetry/order, and fear of falling seriously ill. The person will attempt to minimize or eliminate these unwanted thoughts through the use of compulsions. Compulsions are the behaviors used to cope with obsessions. The most common compulsions are hand washing, checking (as in checking to make sure doors are locked several times a night), and counting.
While most people with OCD only have one to a few main obsessions, the disorder also interferes with many thoughts and actions unrelated to their obsessions. For example:
A person who obsesses over cleanliness will often be caught in a loop: First, they will wash their hands. As they finish, the thought occurs to them that the water may have been contaminated. So they wash again, and this time, upon finishing, they wonder if there were germs in the soap. Again, they wash their hands, and after drying, they will likely wonder who's been touching the towel. This goes on and on - if the person does not execute the compulsions, the obsessive thoughts won't allow them to focus on anything else.
But the pattern often shows in other situations: perhaps the person notices a knife laying out in the kitchen, and suddenly realizes that, if they wanted, they could use it to kill their entire family. This normally isn't a pleasant thought, and the person tries to push it from their mind. But the thought doesn't go away - it stays at the front of the person's mind until the person acts on it (hopefully by putting the knife away or going into another room). These thoughts aren't (or shouldn't be) nearly strong enough to make a person murder anyone, but they are very distracting, unpleasant, persistent, and often damaging. For reasons similar to this example, many people with OCD are uncomfortable around sharp objects or weapons.
Case studies to follow?

## Psychotic Disorders
### Schizophrenia

The schizophrenic disorders are characterized in general by fundamental and characteristic distortions of thinking and perception, and affects that are inappropriate or blunted. Clear consciousness and intellectual capacity are usually maintained although certain cognitive deficits may evolve in the course of time. The most important psychopathological phenomena include thought echo; thought insertion or withdrawal; thought broadcasting; delusional perception and delusions of control; influence or passivity; hallucinatory voices commenting or discussing the patient in the third person; thought disorders and negative symptoms.
The course of schizophrenic disorders can be either continuous, or episodic with progressive or stable deficit, or there can be one or more episodes with complete or incomplete remission. The diagnosis of schizophrenia should not be made in the presence of extensive depressive or manic symptoms unless it is clear that schizophrenic symptoms antedate the affective disturbance. Nor should schizophrenia be diagnosed in the presence of overt brain disease or during states of drug intoxication or withdrawal. (from WHO - ICD 10)

## Sexual Disorders
### Paraphilias
#### Pedophilia

a sexual preference for children of prepubertal or early pubertal age

#### Other Paraphilias
## Drug Related Disorders
### Addiction And Dependence
## Impulse Control Disorders

An Impulse Control Disorder can be loosely defined as the failure to resist an impulsive act or behavior that may be harmful to self or others (Hucker, S. J., 2004). Impulse-control disorders are psychological disorders characterized by the repeated inability to refrain from performing an act. An impulsive behavior or act is considered to be one that is not premeditated or not considered in advance and one over which the individual has little or no control. The concept of impulsivity covers a wide range of “actions that are poorly conceived, prematurely expressed, unduly risky, or inappropriate to the situation and that often result in undesirable consequences” (Daruna & Barnes, 1993, p. 23).
Impulsivity, by Grant (2008) is defined as a predisposition toward rapid, unplanned reactions to stimuli (either internal or external) without thinking of the negative consequences. Impulse control disorders share common core qualities such as repetitive or compulsive engagement in a behavior despite unwanted consequences, diminished control over the problematic behavior, an urge or craving state prior to commitment in the behavior, and a hedonic quality during the performance of the behavior in question. Subjective distress and impaired functioning are often a consequence of impulse control disorders, and their avoidance feeds the cycle of repetitive behaviors. Patients with these disorders continue to struggle with their desire to engage in the behavior that might have terrible outcomes (i.e. addictions, gambling) and it might cause emerging social, occupational, financial, or legal consequences.
Another definition of impulse-control disorders are defined by the American Psychiatric Association (2000) as “the failure to resist an impulse, drive, or temptation to perform an act that is harmful to the person or to others”. Typically the “individual feels an increasing sense of tension or arousal before committing the act, and then experiences pleasure, gratification, or relief at the time of committing the act” (p. 609). Following the act there may or may not be regret, self-reproach, or guilt.
Under many of the poor decision making and impulsive/short sighted behaviors there lays a perceptual distortion called delay discounting (Perna, 2010). Delay discounting is an evaluation process whereby when considering an immediate behavior; a person minimizes the long-term risks or benefits associated with that decision. It is a decrease in the subjective value of a reinforcer (i.e., money, drugs) as a function of time to its delivery. Impulsive behaviors occur when individuals choose small but immediate rewards over long term rewards (or reducing possible long term risks). Eysenck (1977) related impulsivity to risk taking, lack of planning, and making up one’s mind too quickly. Patton et. al.(1995) considered impulsivity in three components;
* Acting on the spur of the moment (motor activation)
* Not focusing on the task at hand (attention)
* Not planning and thinking carefully (lack of future planning)
Impulse Control Disorders are a specific group of impulsive behaviors that have been accepted as psychiatric disorders under the DSM-IV- TR. The following are included under the Impulse Control Disorders in the DSM-IV-TR (APA,2000);
* Intermittent Explosive Disorder is characterized by discrete episodes of failure to resist aggressive impulses resulting in serious assaults or destruction of property.
* Kleptomania is characterized by the recurrent failure to resist impulses to steal objects not needed for personal use or monetary value.
* Pyromania is characterized by a pattern of fire setting for pleasure, gratification, or relief of tension.
* Pathological Gambling is characterized by recurrent and persistent maladaptive gambling behavior.
* Trichotillomania is characterized by recurrent pulling out of one's hair for pleasure, gratification, or relief of tension that result in noticeable hair loss.
* Impulse-Control Disorder Not Otherwise Specified is included for coding disorders of impulse control that do not meet the criteria for any of the specific Impulse-Control Disorders described above or in other sections of the manual.

### Etiology

Grant (2008) suggests similarities regarding impulse control disorders and the existence of a neurobiological feature also present in addiction. Therefore, he suggests that impulse control disorders can be considered as behavioral addictions. The positive responses obtained from treatment with opioid antagonists and glutamatergic agents suggests that the dopamine and possible glutamate systems affected by these medication may have a role in impulse control disorders as well as substance abuse and dependence to substances. The neural systems regulating impulsive, compulsive, and habitual behaviors likely have some differences; however, there seems be overlapping neurobiology (e.g., activation of the OFC) that might explain why several psychiatric disorders have comorbid impulsive and compulsive features (Torregrossa, 2008).
The Prefrontal Cortex- more specifically the orbito-frontal cortex (OFC)- is thought to play a role in the etiology of decision making and impulse control behaviors. According to Jentsch (1999), the Prefrontal Cortex is thought to be impaired in disorders of impulsivity and compulsivity such as drug addiction and obsessive compulsive disorder (OCD), as well as attentional disorders.
The biological theories formulated to explain the causes of impulse control (or lack of) problems are similar to those of substance use. Schmitz (2005) posits a biologically based theory of ICD’s or as he calls them “behavioral addictions”. He hypothesized that the behavioral addictions are using the same neurological reward/pleasure pathways as do substance related disorders. These specific neurocircuits have been identified to take role in the reward/pleasure pathways involved in the reinforcing properties or drug abuse and drug craving. According to Koob (1992), the neurotransmitters which have a role in the reward pathways are dopamine, opioid peptides, glutamate and gamma-amino butyric acid (GABA). Drugs stimulate this pathway and cause the person to feel feelings of intense reward/pleasure. Addictive behaviors are thought to work in this manner too.
Reward Deficiency Hypothesis
The Reward Deficiency Hypothesis proposes that those individuals who have a malfunctioning reward/pleasure circuit are not satisfied with the normal rewards such as food and sex but rather they are in need of unnatural rewards that cause higher thrills and excitement (Becker, 1999; Comings & Blum, 2000) According to Schmitz (2005), impulse control disorders such as kleptomania, or pathological gambling have similar patterns to drug cravings associated with chemical dependency, therefore, they are thought to have their bases in the reward pathways. In example, when a kleptomaniac has the urge to steal, he/she is feeling the thrill and a high that is similar to high from drugs.
The Feeling State Theory (FST)
The Feeling State Theory posits that impulse control disorders were created when positive feelings form links with specific objects or behavior thus forming a state-dependent memory (Miller, 2010). This state dependent memory is formed of feelings and the event: which make up a unit called a ‘feeling state’. This is seen as the cause of impulse control disorders. During the creation of these ‘feelings states’ the person feels intense psycho-physiological arousal and can become fixation on this. Therefore, to feel it again, the will repeat the behavior to reach that state. FST includes the element of memory as well stating that the ‘feeling sate’ is composed of feelings associated with behaviors plus the memory of the behavior. For example, a person who thinks about the emotions and thoughts when he felt good could raise the memory and cause him to repeat the behavior and to be impulse in seeking the event.

### Connections between ICD and OCD, and Addiction

Habits and impulsive behavior have been considered to be at the opposite ends of a behavioral spectrum however, the behaviors that define impulsivity and compulsivity have some commonalities. Compulsivity is the leading cause of obsessive-compulsive disorders where the person is compelled to do a certain act to relieve anxiety/stress even when the behavior seems inappropriate. They repeat these behaviors in a ritualistic manner and as mentioned above, the involve dysfunction in the OFC (Evans, 2004). When we consider impulsivity, it also includes an element of inability to inhibit a motor response and somewhat compulsive in nature. People suffering from an impulse control disorder have mentioned to obsess about performing the act (in relation to their disorder) and being feeling compelled to do so (Grant, 2006).
One difference between the ICD’s and OCD’s is that individuals with ICD’s engaging in repetitive behaviors are considered to be egosyntonic; generally refers to behaviors, values, feelings that are in harmony with or acceptable to the needs and goals of the ego, or consistent with one's ideal self image or self concept. The person feels pleasure, gratification or relief at the time of committing the act. The repetitive behaviors or rituals in OCD’s are considered to be egodystonic (Grant, 2006; Blasczynski, 1999) meaning that the compulsions experienced or expressed are not consistent with the individual's self-perception; the patient realizes the obsessions are not reasonable. Individuals with ICD are generally sensation seekers and that’s why they are impulsively repeating thrilling behaviors, where as OCD individuals are more interested in harm avoidance and repetition of behavior reduces anxiety for a certain time.
Drug addiction is also involves impulsivity (i.e. to take drugs), a compulsion that is pushing someone to take drugs after chronic usage and eventually developing into a habit that is further characterized by automatic responses to take drugs without considering the outcomes. ICDs and substance disorders have similar disturbances related to affective regulation. After performing ICD action and feeling the associated high patients have described the acute onset of depressive symptoms that is similar to those occurring during withdrawal from many substances, including depressed mood, feelings of guilt, fatigue. Another similarity has been the behaviors associated with tolerance and withdrawal. For example, pathological gamblers have reported that they need to progressively increase to larger sums of money in order to feel the desired ‘high’ (Goodman, 1997) (similar to tolerance where to dosage of the substance has to be increased to get the same high). Also, the have reported to have physiological symptoms such as insomnia, anorexia, tremor, headaches, upset stomach, nightmares on discontinuation of gambling (Anderson, 1984).
References
* ↑ Hucker, S.J. (2004) “Disorders of impulse control”. In: Forensic Psychology by O’Donohue, W. and Levensky, E. (eds), Academic Press
* ↑ Daruna, J. H., & Barnes, P. A. (1993). A neurodevelopmental view of impulsivity. In W. G. McCown, J. L. Johnson, & M. B. Shure (Eds.), The impulsive client: Theory, research, and treatment (pp. 23–37). Washington, DC: American Psychological Association.
* ↑ Grant, E. Jon., (2008), Impulse Control Disorders: A Clinician’s Guide to Understanding and Treating Behavioral Addictions, BOOK AND MEDIA REVIEW, pp 209
* ↑ American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (IV-TR). Washington DC: American Psychiatric Association, 2000.
* ↑ Perna, Robert, (2010), Impulsivity, Shorsighted Decisions, and Discounting. A review of Madden, Gregory and Bickel, Warren, (2010), Impulsivity: The Behavioral and Neurological Science of Discounting, PsychCritiques, Vol:55, No: 8, 1
* ↑ Eysenck SB, Eysenck HJ: The place of impulsiveness in a dimensional system of personality description. Br J Soc Clin Psychol, 1977; 16:57–68
* ↑ Patton JH, Stanford MS, Barratt ES: Factor structure of the Barratt Impulsiveness Scale. J Clin Psychol 1995; 51:768–774
* ↑ American Psychiatric Association. (2000). Diagnostic and statistical manual of mental disorders (IV-TR). Washington DC: American Psychiatric Association, 2000.
* ↑ Grant, E. Jon., (2008), Impulse Control Disorders: A Clinician’s Guide to Understanding and Treating Behavioral Addictions, BOOK AND MEDIA REVIEW, pp 209
* ↑ Torregrossa, M, M., Jennifer J. Quinn, and Jane R. Taylor (2008) Impulsivity, Compulsivity, and Habit: The Role of Orbitofrontal Cortex Revisited, BIOL PSYCHIATRY 2008;63:253–255
* ↑ Jentsch JD, Taylor JR (1999): Impulsivity resulting from frontostriatal dysfunction in drug abuse: Implications for the control of behavior by reward-related stimuli. Psychopharmacol 146:373–390.
* ↑ Schmitz, J. M. (2005). The interface between impulse-control disorders and addictions: Are pleasure pathway responses shared neurobiological substrates? Sexual Addiction & Compulsivity, 12, 149-168.
* ↑ Koob, G. F. (1992). Drugs of abuse: Anatomy, pharmacology and function of reward pathways. Trends in Pharmacological Sciences, 13, 177-184.
* ↑ Becker, H. C. (1999). Alcohol withdrawal: Neuroadaptation and sensitization. CNS Spectrums, 4. 38-65.
* ↑ Comings, D. E., & Blum, K. (2000). Reward deficiency syndrome: Genetic aspects of behavioral disorders. Progress in Brain Research, 126, 325-341
* ↑ Schmitz, J. M. (2005). The interface between impulse-control disorders and addictions: Are pleasure pathway responses shared neurobiological substrates? Sexual Addiction & Compulsivity, 12, 149-168.
* ↑ Miller, R. 2010, The Feeling-State Theory of Impulse-Control Disorders and the Impulse-Control Disorder Protocol, Traumatology, 16:3, pp 2-10
* ↑ Evans DW, Lewis MD, Lobst E (2004): The role of the orbitofrontal cortex in normally developing compulsive-like behaviors and obsessive-compulsive disorder.
* ↑ Grant JE, Potenza MN (2006): Compulsive aspects of impulse-control disorders. Psychiatry Clin North Am 29:539 –551.
* ↑ Blaszczynski A. Pathological gambling and obsessivecompulsive spectrum disorders. Psychol Rep 1999;84(1):107–13.
* ↑ Grant JE, Potenza MN (2006): Compulsive aspects of impulse-control disorders. Psychiatry Clin North Am 29:539 –551.
* ↑ Goodman, A., 1997, Sexual addiction. In Lowinson JH, Ruiz P, Millmasn RB, Langrod, JG, eds Substance Abuse, A Comprehensive Textbook. Baltimore, MD: Williams and Wilkins, 1997:340-354
* ↑ Anderson G., Brown, R. I, 1984, Real and Laboratory gambling, sensation seeking and arousal. Br J Psychol. 75:401-410

## Developmental Disorders
### Asperger's Syndrome

Asperger's is now categorized under autism but was historically labeled as "higher functioning" with little to no IQ impairments.

## Personality

Borderline Syndrome