### chemical deficiency:

Bipolar disorder
* accounts for a large proportion of children s psychiatric hospitalizations.
* are a universal phenomenon, however, and occur in all races and nationalities
  - different in children than in adults
* can be difficult to understand
  - severe and long-term, or it can be mild with infrequent episodes
* can have episodes of just mania or mania and depression together
  - significant consequences on an individual's life
* causes extreme changes in mood, thinking, and behavior
  - severe changes of mood and behavior
* chemical deficiency.
* chronic medical condition that can be hard to treat
  - mental health disorder that is genetic in nature
* combination of depression and manic or hypomanic episodes.
* common but serious mental illness.
* complex, chronic disease.
* does occur in preadolescents, although it is uncommon.
* has a strong genetic influence
  - heterogeneous outcome
* involve periods of depression followed by periods of mania.
* involves cycles of depression and elation or mania
  - episodes of mania and depression
  - unusual shifts in mood, energy, and functioning
* is affective disorder
  - an emotional disturbance
* is an illness that causes extreme mood swings
  - needs long-term management
  - where the person's state of mind alternates between extremes
  - associated with hypomania
  - caused by a dominant gene on the X chromosome
  - characterised by extreme states of mind, from depression through to mania
* is characterized by alternating cycles of depression and mania
* is characterized by bouts of depression and mania
  - mania followed by bouts of depressions
  - dramatic mood swings between mania and depression
  - episodes of mania alternating with episodes of depression
  - mood swings, from depression to mania
* is characterized by periods of depression which give way to manic episodes
  - symptoms that fall into several major categories
  - clinical depressions
  - diagnosed in equal numbers of men and women
  - different in children than it is in adults
  - equally common in men and women in the United States
  - highly responsive to treatment with mood stabilizers, including lithium
  - marked by incidents of mania
  - more common in adolescents than in younger children
* is often a chronic recurring condition
  - difficult to recognize and diagnose
  - one of the most well researched mental illnesses
* is probably due to the interaction of many different genes
  - the best known mood disorder
  - rare before puberty
  - recognized by episodes of mania or depression separated by periods of wellness
  - the new name for what used to be called manic depression
  - thought to be genetic
  - treatable, but if ignored, the condition is likely to worsen by the day
  - treated with medicine to stop the mood swings
  - when people alternate between episodes of mania and depression
* lifelong disease.
* lifetime illness.
* major lifelong condition.
* medical disorder requiring a lifetime of medication
* neurobiological brain disorder involving extremes in mood.
* occurs more often among creative writers and artists.
* recurring illness.
* serious, but treatable disorder of the brain chemistry
  - potentially fatal illness
* tends to be inherited.
* tends to run in families, and is believed to be inherited in many cases
  - there is strong evidence that it is inherited
  - worsen with age
* widely misunderstood condition.

Chemical disinfection
* generally lightweight method, easy to use, inexpensive and effective.
* is an integral part of pool water treatment.