Since the introduction of a separate axis in DSM-III (1980), the validity of the categorical nature of the classification of personality disorders has been seriously questioned. Subsequently, a number of multidimensional alternatives have been proposed based on statistical procedures or theoretical considerations. At the same time, the study of the neurobiological underpinnings of personality and personality disorders has created a better understanding of etiological and pathogenetic processes responsible for these chronic disorders. The findings of these studies corroborate some of the major findings of statistical studies regarding the nature of the frequent comorbidity of axis II disorders. In the discussion, a mixed, two-tier diagnostic model is proposed to serve both scientific and clinical aims without the disadvantages of an exclusive choice for either categorical or dimensional approaches to the classification of personality pathology.

Because of the graded nature of adaptational processes, a dimensional diagnostic approach is more adequate than the categorical classification. The broad concept of the serotonin-aggression relationship, irrespective of the diagnostic category, is increasingly questionable and seems to be present in young, white male adults with antisocial personality disorders only. In this group, dopaminergic and neurosteroid-linked mechanisms are important as well.

A fundamental issue in the neurobiology of adaptation disorders is how the hormones of the hypothalamic-pituitary-adrenal (HPA) axis protect the brain from such disorders, and how in a different context these very same stress hormones may enhance vulnerability. This contribution focuses on the corticosteroids which exert through two distinct nuclear receptor types control over gene networks underlying stress system activity in brain. The mineralocorticoid receptor mediates the pro-active mode of corticosteroid action involved in maintenance of basal stress system activity. The glucocorticoid receptor mediates the reactive feedback mode aimed to facilitate recovery from stress-induced disturbance. The balance between these pro-active and reactive modes of control is thought to be of critical importance for homeostasis, and thus for control of hormone-responsive genes which enhance vulnerability to stress-related affective and neurodegenerative disorders.

The cytochrome P450 iso-enzyme system plays a key role in the biotransformation of many drugs, including psychotropics. Its activity is determined by both genetic and environmental factors. The most important iso-enzymes for psychiatry in general are P450 IID6, 3A4 and 1A2. Knowledge about the involvement of these enzymes and biotransformation processes is mandatory because of the individual variability in their metabolic capacity. Regular measurement of plasmaconcentrations of (psycho)pharmacological compounds is therefore essential. In addition, the potential value of pheno- and/or genotyping has to be investigated.

In the training program for residents in psychiatry, scientific education and participation in research projects are relatively underdeveloped. This may result in a gap between recently acquired scientific knowledge and its implementation in clinical practice.

Since the start of the residency training in psychiatry in 1989 in the Vincent van Gogh Institute for Psychiatry, several research lines have been developed especially concerning dimensional diagnostic procedures, evaluation of treatment effects, stress and psychopathology, pharmacokinetics of psychotropic compounds and disordered impulse and aggression regulation. It is concluded that active participation in research projects by both psychiatrists and residents in psychiatry is increasingly mandatory due to social-economic en scientific developments. Despite several countervailing factors, the Vincent van Gogh Institute for Psychiatry has succeeded in the creation of a scientific orientation in the residency program resulting in a number of publications.

With aging, most cognitive functions decline, especially processes concerning memorizing, attention, concentration, organizing, planning and problem solving. Neuropsychology can make an important contribution in early and differential diagnostics. The borderline between normal and pathological cognitive aging is especially important in this respect. The neuropsychologist gains insight in medical, biological, psychological and social factors of the aging person. Has the profile of complaints and deficits a normal background or is a pathological process taking place? It is important to people who are unnecessarily worried about possible dementia.

Neuropsychological assessment also provides information about a patient's disturbed and undisturbed cognitive functions, their personality and their way of coping with problems in every day's life. This is of major importance, because it provides information and possibilities for biological or psychological interventions. Because of the complexity of problems that may occur, it is necessary that the neuropsychologist is experienced and works in a multidisciplinary team in which neurological and psychiatric expertise is present.

Classical psychiatric taxonomy appears to be increasingly inadequate in the diagnostic process of mentally retarded subjects. The reasons for this are the atypical presentation of classical psychiatric disorders, special diagnostic entities like cycloid psychosis and unstable mood disorder and the existence of so-called behavioural phenotypes related to syndromes with a known genetic etiology. In addition, disturbed behaviour may be the result of somatic or neurologic comorbidity and induced to adverse drug events.

The European psychiatric literature is rich in descriptions and studies of atypical psychotic disorders. Most of these are finally deemed to be varieties of the affective or schizophrenic disorders, which in turn are regarded to be typical.

The acute polymorphic psychotic disorder according to the ICD-10, and the periodic catatonia of Gjessing, although hardly recognized and acknowledged, are good candidates to be considered as separate psychotic disease entities.

Although the Hamilton Rating Scale for Depression (HRSD) is the most frequently used rating scale for quantifying depressive states, it has been criticized for its reliability and its usability in clinical practice. This criticism is less applying to the Montgomery-Asberg Depression Rating Scale (MADRS). Goal of the present study is to investigate the reliability and validity, and clinical relationship between the HRSD and the MADRS. For 60 out-patients with diagnosed depression (DSM IV296.2x, 296.3x, 300.40 and 311.00), the HRSD and MADRS were scored at baseline and 6 weeks later by an independent rater according to a structured interview. Also the Clinical Global Impression (CGI) was assessed by a psychiatrist. Satisfying agreement was found between the totalscores (r= .75, p>.000 en r=.92, p>.000 respectively, at baseline and 6 weeks later). Furthermore agreement was found between the items of both scales, and these agree with the clinical impression. The reliability of the MADRS is more stable than the reliability of the HRSD (α = .6367 and α =.8900 vs α = .2193 and α = .8362 at baseline and at endpoint respectively). Considering the ease of scoring both scales in one interview and the widely international use of the HRSD, scoring both the HRSD and the MADRS to measure the severity of a depression seems to be an acceptabel covenant.