Medical boards around the world face the challenge of creating competency-based postgraduate training programs. Recent legislation requires that all postgraduate medical training programmes in The Netherlands be reformed. In this article the Dutch Advisory Board for Postgraduate Curriculum Development shares some of their experiences with guiding the design of specialist training programs, based on the Canadian Medical Educational Directives for Specialists (CanMEDS). All twenty-seven Dutch Medical Specialty Societies take three steps in designing a curriculum. First they divide the entire content of a specialty into logical units, so-called 'themes'. The second step is discussing, for each theme, for which tasks trainees have to be instructed, guided, and assessed. Finally, for each task an assessment method is chosen to focus on a limited number of CanMEDS roles. This leads to a three step training cycle: (i) based on their in-training assessment and practices, trainees will gather evidence on their development in a portfolio; (ii) this evidence stimulates the trainee and the supervisor to regularly reflect on a trainee's global development regarding the CanMEDS roles as well as on the performance in specific tasks; (iii) a personal development plan structures future learning goals and strategies. The experiences in the Netherlands are in line with international developments in postgraduate medical education and with the literature on workplace-based teaching and learning.

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Nerve impulse generation and propagation are often thought of as solely electrical events. The prevalence of this view is the result of long and intense study of nerve impulses in electrophysiology culminating in the introduction of the Hodgkin-Huxley model of the action potential in the 1950s. To this day, this model forms the physiological foundation for a broad area of neuroscientific research. However, the Hodgkin-Huxley model cannot account for non-electrical phenomena that accompany nerve impulse propagation, for which there is nevertheless ample evidence. This raises the question whether the Hodgkin-Huxley model is a complete model of the nerve impulse. Several alternative models have been proposed that do take into account non-electrical aspects of the nerve impulse and emphasize their importance in gaining a more complete understanding of the nature of the nerve impulse. In our opinion, these models deserve more attention in neuroscientific research, since, together with the Hodgkin-Huxley model, they will help in addressing and solving a number of questions in basic and applied neuroscience which thus far have remained outside our grasp. Here we provide a historico-scientific overview of the developments that have led to the current conception of the action potential as an electrical phenomenon, discuss some major objections against this conception, and suggest a number of scientific factors which have likely contributed to the enduring success of the Hodgkin-Huxley model and should be taken into consideration whilst contemplating the formulation of a more extensive and complete conception of the nerve impulse.

In half of Obsessive Compulsive Disorder (OCD) patients the disorder runs a chronic course despite treatment. The factors determining this unfavourable outcome remain unknown. The Netherlands Obsessive Compulsive Disorder Association (NOCDA) study is a multicentre naturalistic cohort study of the biological, psychological and social determinants of chronicity in a clinical sample. Recruitment of OCD patients took place in mental health organizations. Its design is a six-year longitudinal cohort study among a representative clinical sample of 419 OCD patients. All five measurements within this six-year period involved validated semi-structured interviews and self-report questionnaires which gathered information on the severity of OCD and its co-morbidity as well as information on general wellbeing, quality of life, daily activities, medical consumption and key psychological and social factors. The baseline measurements also include DNA and blood sampling and data on demographic and personality variables. The current paper presents the design and rationale of the study, as well as data on baseline sample characteristics. Demographic characteristics and co-morbidity ratings in the NOCDA sample closely resemble other OCD study samples. Lifetime co-morbid Axis I disorders are present in the majority of OCD patients, with high current and lifetime co-morbidity ratings for affective disorders (23.4% and 63.7%, respectively) and anxiety disorders other than OCD (36% current and 46.5% lifetime).

Patients with obsessive-compulsive disorder (OCD) not only suffer from obsessive-compulsive symptoms, but also the disorder is associated with aberrant social functioning and a diminished quality of life (QoL). Although studies concerning the effect of treatment interventions on symptoms are common, studies with regard to the effect of treatment interventions on QoL are scarce. We examined the effect of a pharmacological intervention on QoL in 150 patients with OCD. Furthermore, we studied whether two different drugs, venlafaxine and paroxetine, differed in their effect on QoL. Finally, we examined whether any found improvement in QoL was related to improvement in symptoms and/or the baseline self-directedness score, which is one of the character dimensions of the psychobiological model of Cloninger. We demonstrated that QoL, as assessed with the Lancashire Quality of Life Profile, improved following pharmacological intervention, for which paroxetine and venlafaxine appeared to be equally effective. Furthermore, neither improvement in symptoms, nor baseline self-directedness, was associated with the improvement in QoL.

Borsboom and colleagues have recently proposed a “network theory” of psychiatric disorders that conceptualizes psychiatric disorders as relatively stable networks of causally interacting symptoms. They have also claimed that the network theory should include non-symptom variables such as environmental factors. How are environmental factors incorporated in the network theory, and what kind of explanations of psychiatric disorders can such an “extended” network theory provide? The aim of this article is to critically examine what explanatory strategies the network theory that includes both symptoms and environmental factors can accommodate. We first analyze how proponents of the network theory conceptualize the relations between symptoms and between symptoms and environmental factors. Their claims suggest that the network theory could provide insight into the causal mechanisms underlying psychiatric disorders. We assess these claims in light of network analysis, Woodward’s interventionist theory, and mechanistic explanation, and show that they can only be satisfied with additional assumptions and requirements. Then, we examine their claim that network characteristics may explain the dynamics of psychiatric disorders by means of a topological explanatory strategy. We argue that the network theory could accommodate topological explanations of symptom networks, but we also point out that this poses some difficulties. Finally, we suggest that a multilayer network account of psychiatric disorders might allow for the integration of symptoms and non-symptom factors related to psychiatric disorders and could accommodate both causal/mechanistic and topological explanations.

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