[citation needed] Mood disorders may also be substance induced, or occur in response to a medical condition.

Recent research has concluded that, while this may be true in some cases, alcohol misuse directly causes the development of depression in a significant number of heavy drinkers.

[38][40][41] Depression and other mental health problems associated with alcohol misuse may be due to distortion of brain chemistry, as they tend to improve on their own after a period of abstinence.

While the anxiolytic and hypnotic effects of benzodiazepines may disappear as tolerance develops, depression and impulsivity with high suicidal risk commonly persist.

[44] These symptoms are "often interpreted as an exacerbation or as a natural evolution of previous disorders and the chronic use of sedatives is overlooked".

[51] As with alcohol, the effects of benzodiazepine on neurochemistry, such as decreased levels of serotonin and norepinephrine, are believed to be responsible for the increased depression.

[61][62][63] While benzodiazepine-induced depressive disorder may be exacerbated immediately after discontinuation of benzodiazepines, evidence suggests that mood significantly improves after the acute withdrawal period to levels better than during use.

[70] Meta-analyses show that high scores on the personality domain neuroticism are a strong predictor for the development of mood disorders.

This theory helps to explain why negative life incidents precede depression in around 80 percent of cases,[74][75] and why they so often strike people during their peak reproductive years.

[73] A depressed mood is a predictable response to certain types of life occurrences, such as loss of status, divorce, or death of a child or spouse.

A depressed mood can be seen as an adaptive response, in the sense that it causes an individual to turn away from the earlier (and reproductively unsuccessful) modes of behavior.

[76] The occurrence of low-level depression during the winter months, or seasonal affective disorder, may have been adaptive in the past, by limiting physical activity at times when food was scarce.

[76] It is argued that humans have retained the instinct to experience low mood during the winter months, even if the availability of food is no longer determined by the weather.

[81][82] Underlying these sex differences, studies have shown a dysregulation of stress-responsive neuroendocrine function causing an increase in the likelihood of developing these affective disorders.

This chronic stress is associated with sustained CRF release, resulting in the increased production of anxiety- and depressive-like behaviors and serving as a potential mechanism for differences in prevalence between men and women.

[43] Bipolar disorders underwent a few changes in the DSM-5, most notably the addition of more specific symptomology related to hypomanic and mixed manic states.

Major depressive disorder (MDD) also underwent a notable change, in that the bereavement clause has been removed.

Lithium specifically has been proven to reduce suicide and all causes of mortality in people with mood disorders.

[90] If mitochondrial dysfunction or mitochondrial diseases are the cause of mood disorders like bipolar disorder,[78] then it has been hypothesized that N-acetyl-cysteine (NAC), acetyl-L-carnitine (ALCAR), S-adenosylmethionine (SAMe), coenzyme Q10 (CoQ10), alpha-lipoic acid (ALA), creatine monohydrate (CM), and melatonin could be potential treatment options.

[93] According to a substantial number of epidemiology studies conducted, women are twice as likely to develop certain mood disorders, such as major depression.

[94] In 2011, mood disorders were the most common reason for hospitalization among children aged 1–17 years in the United States, with approximately 112,000 stays.

They also found that the likelihood of 'engaging in creative activities on the job' is significantly higher for bipolar than nonbipolar workers.

Clinical studies have shown that those in a manic state will rhyme, find synonyms, and use alliteration more than controls.

Those in a manic state are more emotionally sensitive and show less inhibition about attitudes, which could create greater expression.