Impulsivity is a personality trait characterized by the inclination of an individual to initiate behavior without adequate forethought as to the consequences of their actions, acting on the spur of the moment. Eysenck and Eysenck related impulsivity to risk-taking, lack of planning, and making up one's mind quickly. Impulsivity has been shown to be a major component of various neuropsychiatric disorders such as ADHD, substance abuse disorders and bipolar disorder

Bipolar disorder

Bipolar disorder or bipolar affective disorder, historically known as manic–depressive disorder, is a psychiatric diagnosis that describes a category of mood disorders defined by the presence of one or more episodes of abnormally elevated energy levels, cognition, and mood with or without one or...

. Impulsivity has been shown to have a genetic component and may be inheritable. Abnormal patterns of impulsivity may also be an acquired trait as a result of various neurodegenerative diseases, traumatic brain injury

Traumatic brain injury

Traumatic brain injury , also known as intracranial injury, occurs when an external force traumatically injures the brain. TBI can be classified based on severity, mechanism , or other features...

 (TBI), hypoxic ischemic encephalopathy, intrauterine hypoxia

Intrauterine hypoxia

Intrauterine hypoxia occur when the fetus is deprived of an adequate supply of oxygen. IH is used to describe inadequate oxygen availability during the gestation period, birth asphyxia can result from inadequate supply of oxygen immediately prior to, during or just after delivery...

, bacteria

Bacteria

Bacteria are a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria have a wide range of shapes, ranging from spheres to rods and spirals...

l or viral

Virus

A virus is a small infectious agent that can replicate only inside the living cells of organisms. Viruses infect all types of organisms, from animals and plants to bacteria and archaea...

 infections or neurotoxicity

Neurotoxicity

Neurotoxicity occurs when the exposure to natural or artificial toxic substances, which are called neurotoxins, alters the normal activity of the nervous system in such a way as to cause damage to nervous tissue. This can eventually disrupt or even kill neurons, key cells that transmit and process...

 as a result of chemical exposure. The orbitofrontal cortex

Orbitofrontal cortex

The orbitofrontal cortex is a prefrontal cortex region in the frontal lobes in the brain which is involved in the cognitive processing of decision-making...

 and right inferior frontal gyrus

Inferior frontal gyrus

The inferior frontal gyrus is a gyrus of the frontal lobe . It is labelled gyrus frontalis inferior, its Latin name...

 have been shown to play a part in impulse control.

As a personality trait, impulsivity is part of normal behavior as it contributes to adaptive functioning. To do something and not be aware, especially for young children, is relatively common. Recent psychological research has suggested that there are various facets of impulsivity. Some researchers have proposed a 3-factor model according to impulsivity; attention

Attention

Attention is the cognitive process of paying attention to one aspect of the environment while ignoring others. Attention is one of the most intensely studied topics within psychology and cognitive neuroscience....

al ("getting easily bored"), motor

Motor system

The motor system is the part of the central nervous system that is involved with movement. It consists of the pyramidal and extrapyramidal system....

 ("going into action") and cognitive ("inability to plan") factors. Recent theories have suggested five separate aspects of impulsivity:

• Positive urgency; the tendency to act rashly while in a positive mood.
• Negative urgency; the tendency to act rashly while in a negative mood.
• Lack of premeditation; the inability to anticipate the future consequences of actions.
• Lack of perseverance; the inability to follow through on a task
• Sensation-seeking; the experience of positive feelings towards risky actions.

Psychometric tests for impulsivity

• Lifetime History of Impulsive Behaviors; a self-report questionnaire of the lifetime prevalence of impulsive behavior.
• UPPS Impulsive Behavior Scale (Whiteside and Lynam; 2001); a 45-item self-report questionnaire which distinguishes four facets of impulsivity: urgency, lack of premeditation, lack of perseverance, and sensation-seeking. It is scored on a 4-point scale from Strongly Agree to Strongly Disagree.
  • UPPS-P Impulsive Behavior Scale (UPPS-P); a revised version of the UPPS is a 59-item self-report questionnaire that adds an additional factor, "positive urgency".
  • UPPS-R Interview (UPPS-R); Semi-structured interview format for UPPS-P Impulsive Behavior Scale.
• Barratt Impulsiveness Scale; a 30-item self-report questionnaire.