it is estimated that around 6.5 per cent of the total population in Bangladesh have been suffering from psychiatric disorders. A large portion of them (about 2.9 per cent) do suffer from depressive disorders and women are affected by depression four times as frequently as men. Though the causes of depression are multi-factorial but in Bangladesh the main cause may be due to socio-economical and political inconsistency especially when there is imbalance between earning and expenditure in predisposed persons.

Appetite change is a cardinal feature in depression. This symptom is reported by 77-90 per cent of all depressed patients. Among these types of patients 4 out of 5 will have a loss of appetite. Anorexia or weight loss is strongly associated with the diagnosis of melancholia and a family history of depressive illness. The patient with a diminished food supply (semi-starvation) may undergo profound alterations in nutritional metabolism. The basic adaptation is non-complicated semi-starvation and body wasting with subcutaneous fat loss and muscle wasting. Basic disturbance during protein deficiency are muscle wasting and a distortion of hepatic visceral protein synthesis leading to lower serum protein levels.

Depression has been a prominent feature of the neuropsychiatric disorders attributed to folic acid deficiency. Vitamin B 12 deficiency usually takes much longer to develop than folate deficiency owing to the much greater body storage of vitamin B 12. It is already apparent that folate and its derivatives have potent excitatory properties and may play a part in synaptic events, whereas there is no evidence for this with vitamin B 12. It is interesting; therefore, that deficiency of a substance with excitatory properties leads most commonly to depression.

Diagnosis of depressive disorders

In recent years, there has been impressive progress in diagnosing depression. The features of depressive disorders include

a)Dysphoric mood or loss of interest or pleasure in all or almost all usual activities and pastimes.

b)At least 4 of 8 selected symptoms of a psychological, physical and behavioral nature (worthlessness and guilt, suicidal thoughts, sleep disturbance, appetite changes, psychomotor agitation and retardation, loss of interest or pleasure, loss of energy, poor concentration) have been present nearly everyday for a period of at least two weeks.

c)Lack of preoccupation with mood-incongruent delusion or hallucination or bizarre behavior; and

d)Absence of schizophrenia, organic mental disorder or uncomplicated bereavement.

Mood Sadness, complaints of depression, gloom, dejection and crying may charecterise depressed mood.

Physical symptoms: Sleep and appetite disturbance are frequently associated with endocrine disorders. Such symptoms do not satisfactorily discriminate depression from general medical patients.

Function and behavior: Generally depressed patients feel most fatigued when they get up in the morning and gradually improve as the day goes on. Depressed patients may complain of diminished ability to think or concentrate such as slow thinking or indecisiveness. Illness and hospitalisation induce mild degree of cognitive dysfunction.

Nutritional factors as psycho pathogenesis of depression

Malnourishment may be directly related to endocrine abnormalities. Some vitamins act as co-enzymes which exert significant anti-depressant action in patients of all ages.

In one study red blood cell folate concentrations were estimated in patients with major depressive disorders and normal controls. Results showed significantly lower serum and RBC folate concentration in patient with major depressive disorders than that of normal control.

Malnutrition may be assessed by means of standard anthropometric measurements, consist of clinical estimation of muscle mass, fat storage or both through body weight, length, wrist circumference, mean arm circumference and triceps skin folds thickness and biochemical measurements of serum proteins like albumin, pre-albumin and transferring of clinical malnutrition. Recently it has been established that hypotransferrinemia is a hallmark for severe depression.

Conclusion

Modern civilization is not free from stress and anxiety which lead to depressive disorder making uncomfortable personal social life. Depression represents a major challenge to modern medicine. In most cases, it can be effectively treated by vitamins, correction of nutritional deficiencies, and treatment of secondary causes along with antidepressant cognitive psychotherapy and in some cases electro-convulsive therapy.

However, recognition and appropriate management of cases of depression in the medically ill is still inadequate. Clinicians should be aware of that mood changes are a major and life threatening complication of endocrine diseases, particularly in Cushing's syndrome, Addison's disease, Hyperthyroidism, Hypothyroidism and Hyperprolactemia.

Proper advice may be given to the mass population in the community for taking balanced diet with containing vitamins, iron and iodine as a part of prevention of depressive illness to some extent where the cause lies in the above mentioned factors.