Mood disorders

The essentials

Mood disorders (also called affective disorders) involve disturbances in emotional state. The two main groups are depressive disorders and bipolar and related disorders.

Major depressive disorder is a period of depressed mood and/or loss of interest or pleasure in most activities, along with other symptoms such as change in body weight, constant sleep problems, tiredness, inability to think clearly, agitation, greatly slowed behaviour, feelings of worthlessness or excessive guilt, and thoughts of death and suicide.

Key points

• Mania: an episode of euphoric, elated or irritable mood with excessive activity, rapid speech, racing thoughts, reduced need for sleep and grand plans.
• Bipolar I disorder: involves both manic and depressive episodes; it was earlier called manic-depressive disorder. Pure mania is rare.
• Risk factors for depression: genetic make-up and heredity, age (women are more at risk in early adulthood, men in early middle age), gender (women are more likely than men to report depression), negative life events and lack of social support.
• Suicide: depression is a major risk factor. Warning signs include talking about death, giving away possessions, withdrawal, sudden changes in behaviour and expressions of hopelessness. Suicide is preventable; such signs must be taken seriously and the person helped to get professional support.
• Helpful responses: listen without judging, avoid leaving the person alone if at risk, and connect them to a counsellor, doctor or helpline.
• Low serotonin activity has been linked with depression.

Exam tips

• Distinguish depression (only low episodes) from bipolar disorder (manic and depressive episodes).
• Case questions often describe mania through rapid speech, little sleep and unrealistic plans.

Common mistakes

• Treating ordinary sadness after a loss as major depression; the disorder involves severe, lasting symptoms that impair functioning.
• Thinking people who talk about suicide never attempt it; such talk is a warning sign.