Depression is common as a normal response to situational stress and is usually transient. By contrast, depressive disorders are persistent. A causative factor is not obviously present and the term endogenous depression is sometimes used for the condition.
In additional to situational factors which cause depression, other factors may be linked to depressive illnesses. Depression may occur in people with chronic mental illness e.g. neurotic personality disorder, schizophrenia. It may occur as a consequence of hormonal (endocrine) disorders and also with use of hormone-based drugs (steroids, sex hormones, oral contraceptives). It may be associated with chronic illnesses e.g. cancer, where abnormal physiological and biochemical changes may be contributing factors. Physiological changes may also induce depression e.g. hormonal changes associated with menstruation, menopause and puberty.

The depressive illness most commonly seen in the community can be broadly divided into two groups viz. bi-polar affective disorder and depressive (unipolar) disorders.

Depressive disorders are associated with mood depression and disinterest in occupation, social interaction, sex and personal appearance. Sleep disturbance, difficulty with concentration, loss of appetite (anorexia) and delusional thoughts may occur. Lethargy, headaches, constipation and other somatic symptoms may be present. Suicidal thoughts give some indication of the severity of the problem.

Acupuncture is effective for the treatment of situational depression as well as for mild depressive illness, in conjunction with psychological counselling. Moderate to severe depression requires the use of anti-depressant drugs.

Bipolar depressive illness is characterised by episodes of depression interspersed with periods of mania. Features of mania include initial feelings of wellbeing, euphoria and elation. There may be paradoxical nervousness and irritability which may be associated with aggression. Increase in activity and work capacity may occur. Increased sexual and promiscuous activity is not uncommon. Sleep impairment and a decrease in food intake can occur. Rapid thinking is characterised by alteration in speech which reflects both rapid flighty sequencing of ideas and causal association of words and thoughts. Conversations mimic a paper chase. Grandiose ideas with unrealistic perception of the subject’s own importance, capability and importance are common.

Mild mania or hypomania may occur and can be difficult to recognise. Shortened sleep, irritability, over-confidence, over-responsiveness, poor judgement, increased sexual interest all give some indication of the disorder.

Drugs are the mainstay of management in all phases of bipolar disorders. Acupuncture has a secondary supportive role in this disorder