Mood disorders

• Public health interventions that reduce the availability of means for suicide, such as guns, can have powerful effects.
• Depressive disorders include major depressive disorder (MDD) and persistent depressive disorder, along with the newer diagnoses of premenstrual dysphoric disorder and disruptive mood dysregulation disorder.
• MDD is episodic, and recurrence is common.
• Persistent depressive disorder is characterized by low levels of symptoms that last at least 2 years.
• MDD is one of the most common psychological disorders, affecting at least 16.2% of people during their lifetime.
• Bipolar disorders include bipolar I disorder, bipolar II disorder, and cyclothymia.
• Bipolar I disorder is defined by mania.
• Bipolar II disorder is defined by hypomania and episodes of depression.
• Cyclothymic disorder is characterized by low levels of manic and depressive symptoms that last at least 2 years.
• Bipolar I disorder and bipolar II disorder are episodic.
• Recurrence is even more common in these disorders than it is in major depressive disorder.
• Bipolar I disorder affects less than 1% of the population.
• Estimates of the prevalence of bipolar II disorder are varied (from 0.4% to 2%).
• Cyclothymic disorder may affect 4% of the population.
• Bipolar disorder is strongly heritable, and MDD is somewhat heritable.
• Imaging research on neurotransmitters has provided conflicting findings regarding mood disorders.
• People with depression show diminished sensitivity to drugs that increase dopamine levels, and those with mania show increased sensitivity to drugs that increase dopamine levels.
• Bipolar disorders and unipolar disorders are tied to elevated activity of the amygdala and the anterior cingulate and to diminished activity in the hippocampus and regions of the prefrontal cortex during tasks that involve emotion and emotion regulation.
• Unipolar disorder is related to diminished volume of the hippocampus, anterior cingulate, and prefrontal cortex.
• Unipolar and bipolar disorder are related to thinner frontal and temporal cortices.
• Bipolar disorder is related to heightened activation of the striatum, but activity in this region is low among those with depression.
• The cortisol awakening response (CAR) is elevated in unipolar depression and bipolar depression.
• Pro-inflammatory cytokines are sometimes elevated in people with unipolar depression and those with bipolar disorder.
• Socioenvironmental models focus on the role of childhood adversity, recent negative life events (and particularly negative interpersonal life events), lack of social support, marital discord, and expressed emotion as triggers for episodes.
• The personality trait that is most closely related to depression is neuroticism.
• Neuroticism predicts the onset of depression.
• Influential cognitive theories include Beck’s cognitive theory, hopelessness theory, and rumination theory.
• According to hopelessness theory, beliefs that a life event will have stable global consequences can instill a sense of hopelessness, which in turn results in depression.
• Psychoeducation, family therapy, and cognitive therapy are helpful adjuncts to medication for bipolar disorder; there is some support for interpersonal psychotherapy as well.
• Psychological influences on suicidal ideation include poor problem solving and hopelessness.
• Mania also can be triggered by sleep deprivation.
• Research suggests that suicide prevention can work.
• All posit that depression can be caused by cognitive factors, but the nature of the cognitive factors differs across theories.
• Repetitive transcranial magnetic stimulation is FDA-approved for people with antidepressant-resistant depression.
• Rumination theory focuses on the negative effects of repetitively dwelling on the reasons for a sad mood.
• For people with a psychological disorder, medications and psychotherapies targeting those symptoms help reduce suicidality.
• Early adversity and negative life events influence the function of the cortisol system, the levels of pro-inflammatory cytokines, neural activity in response to emotion stimuli, and the dopamine and serotonin systems.
• Prospective evidence is available for each model.
• Lithium is the best-researched treatment for bipolar disorder, but antipsychotic and anticonvulsant medications also help decrease manic symptoms.
• Several psychological therapies are effective for depression, including interpersonal psychotherapy, cognitive therapy, behavioral activation therapy, and behavioral couples therapy.