Four common disorders characterized by instability in mood and emotions are Borderline Personality Disorder, Bipolar Disorder, Premenstrual Dysphoric Disorder and Drug Abuse.

Borderline Disorder
Also called emotionally unstable personality disorder. Unstable relations, impulsivity, recklessness, explosiveness. Borderline personality disorder (BPD) is defined within the fields of psychiatry and clinical psychology as a mental condition characterized primarily by emotional dysregulation, extreme "black and white" thinking, or "splitting" (believing that something is one of only two possible things, and ignoring any possible "in-betweens"), and chaotic relationships. It is described by mental health professionals as a serious mental illness characterized by pervasive instability in mood, interpersonal relationships, self-image, identity, and behavior, as well as a disturbance in the individual's sense of self. In extreme cases, this disturbance in the sense of self can lead to periods of dissociation.

The disturbances suffered by those with borderline personality disorder have a wide-ranging and pervasive negative impact on many or all of the psychosocial facets of life, including employability and relationships in work, home, and social settings.


Bipolar (Manic - Depressive) Disorder
Dramatic mood swings between overly "high" (manic) states and depression, with periods of normal mood in between. Mania is a severe medical condition characterized by extremely elevated mood, energy, and unusual thought patterns. There are several possible causes for mania, but it is most often associated with bipolar disorder, where episodes of mania may cyclically alternate with episodes of clinical depression. Though the elevated mood and energy level typical of mania could be seen as a benefit, mania generally has many undesirable consequences and has the potential to be very destructive. Classic symptoms include rapid speech, racing thoughts, decreased need for sleep, hypersexuality, euphoria, grandiosity, irritability, and increased interest in goal-directed activities. Mild forms of mania, known as hypomania, cause little or no impairment; more severe forms of mania do cause impairment and may even feature grandiose delusions or hallucinations. In the most extreme cases, manic patients may need to be hospitalized to protect themselves and others. Mania and hypomania have also been associated with creativity and artistic talent.

Premenstrual Dysphoric Disorder (PMDD)
Irritability and mood swings in the week before a menstruation in women. Premenstrual syndrome (PMS) (also called PMT or Premenstrual Tension) is a collection of physical, psychological, and emotional symptoms related to a woman's menstrual cycle. While most women (about 80 to 95 percent) of child-bearing age have some premenstrual symptoms, women with PMS have symptoms of "sufficient severity to interfere with some aspects of life". Further, such symptoms are predictable and occur regularly during the two weeks prior to menses. The symptoms vanish after the bleeding starts, but may continue even after bleeding has begun. About 14 percent of women between the ages of 20 to 35 get so affected that they must stay home from school or work.

Substance Abuse Kicks and Abstinence
Substance abuse (and other kinds of abuse) has its own periodicity of kicks and abstinence symptoms. Drug abuse has a wide range of definitions related to taking a psychoactive drug or performance enhancing drug for a non-therapeutic or non-medical effect. Some of the most commonly abused drugs include alcohol, amphetamines, barbiturates, cocaine, methaqualone, opium alkaloids, and minor tranquilizers. Use of these drugs may lead to criminal penalty in addition to possible physical, social, and psychological harm, both strongly depending on local jurisdiction. Other definitions of drug abuse fall into four main categories: public health definitions, mass communication and vernacular usage, medical definitions, and political and criminal justice definitions