Anorexia nervosa (AN) has serious negative effects on multiple organs and systems of the human body. As patients often do not make their eating disorder the subject of discussion, the physician is forced to rely on the physical examination and laboratory parameters as diagnostic hints. Obvious signs of AN are a body mass index (BMI) below 17.5 kg/m, dry and scaly skin, lanugo, edema, acrocyanosis, petechias, dental problems, and low blood pressure. However, because the often complex laboratory alterations can be difficult for the general psychiatrist to interpret, this article presents some useful guidelines. The plasma of patients with AN often shows alterations in laboratory parameters and appetite regulators, including electrolytes, liver enzymes, leukocyte count, hemoglobin (Hb), leptin, neuropeptide Y (NPY), triiodothyronine (T3), follicle-stimulating hormone (FSH), luteinizing hormone (LH), estrogen, ghrelin, pancreatic polypeptide (PP), tumor necrosis factor-alpha (TNF-alpha), and cortisol. Medical problems secondary to AN or due to the treatment itself may lead to further laboratory abnormalities. To date, despite these associated laboratory alterations, the diagnosis of anorexia is a clinical one, based on weight and specific psychopathology.

Nervous and immune system interact through many different messenger substances such as neurotransmitters, cytokines or neuropeptides. For instance, neuropeptides are capable of affecting the metabolism of cells belonging to the immune system. Conversely, cytokines such as tumor necrosis factor (TNF)-alpha, interferon (IFN)-alpha and IFN-gamma, contribute to the receptor resistance of neuropeptides, reduce the availability of amino acids which are needed for the synthesis of neurotransmitters or show neurotoxic effects. Other cytokines like granulocyte-colony stimulating factor (G-CSF) may be highly attractive candidates for the treatment of neurodegenerative conditions. Cytokines are decisively involved in the pathophysiology of psychiatric disorders such as depression, schizophrenia or anorexia nervosa as well as in neurological, respectively neurodegenerative diseases like Parkinson's or Alzheimer's. This connection between the immune system and the pathogenesis of psychiatric disorders leads to the concept that immunomodulatory drugs which are already in use for various diseases related to the immune system may also be efficient in the treatment of psychiatric disorders. This article is supposed to give an overview over the current concepts and possibilities since hopefully these hypotheses lead to new therapeutical strategies for psychiatric patients in the future.

A remarkable number of targeted interventions aimed at reducing the stigma attached to mental illness have been carried out. However, due to methodological limitations no definite assessment of the effect of these interventions is possible at the present time. There is a pressing need for research that adheres more closely to the methodological standards of evaluation research.

To correctly diagnose a patient with anorexia nervosa, medical history according to DSM-IV or ICD-10 criteria and the physical examination is essential. Furthermore, it is useful for a physician to have knowledge regarding typical alteration in laboratory parameters of anorectic patients to realize diagnostical hints. Typical laboratory changes, although not exclusively seen in anorexia nervosa, include hyponatremia, hypokalemia, hypochloremia, liver enzyme elevation, and low red and white blood cell count. The hormones leptin, neuropeptide Y (NPY), triiodothyronine (T3), follicle-stimulating hormone (FSH), luteinizing hormone (LH) and oestrogen are usually below the normal range, whereas ghrelin, pancreatic polypeptide (PP), tumor necrosis factor-alpha (TNF-alpha) and cortisol levels are reported to be typically elevated.

A concretised understanding far from Freud's original conception of unconscious conflict dominates, which is even stronger in the former communist parts of Germany. Psychoanalytical terms do not necessarily carry a psychoanalytical significance with the public.