A Dynamical Systems View of Psychiatric Disorders-Theory: A Review.

Importance: Psychiatric disorders may come and go with symptoms changing over a lifetime. This suggests the need for a paradigm shift in diagnosis and treatment. Here we present a fresh look inspired by dynamical systems theory. This theory is used widely to explain tipping points, cycles, and chaos in complex systems ranging from the climate to ecosystems. Observations: In the dynamical systems view, we propose the healthy state has a basin of attraction representing its resilience, while disorders are alternative attractors in which the system can become trapped. Rather than an immutable trait, resilience in this approach is a dynamical property. Recent work has demonstrated the universality of generic dynamical indicators of resilience that are now employed globally to monitor the risks of collapse of complex systems, such as tropical rainforests and tipping elements of the climate system. Other dynamical systems tools are used in ecology and climate science to infer causality from time series. Moreover, experiences in ecological restoration confirm the theoretical prediction that under some conditions, short interventions may invoke long-term success when they flip the system into an alternative basin of attraction. All this implies practical applications for psychiatry, as are discussed in part 2 of this article. Conclusions and Relevance: Work in the field of dynamical systems points to novel ways of inferring causality and quantifying resilience from time series. Those approaches have now been tried and tested in a range of complex systems. The same tools may help monitoring and managing resilience of the healthy state as well as psychiatric disorders.

A Dynamical Systems View of Psychiatric Disorders-Practical Implications: A Review.

Importance: Dynamical systems theory is widely used to explain tipping points, cycles, and chaos in complex systems ranging from the climate to ecosystems. It has been suggested that the same theory may be used to explain the nature and dynamics of psychiatric disorders, which may come and go with symptoms changing over a lifetime. Here we review evidence for the practical applicability of this theory and its quantitative tools in psychiatry. Observations: Emerging results suggest that time series of mood and behavior may be used to monitor the resilience of patients using the same generic dynamical indicators that are now employed globally to monitor the risks of collapse of complex systems, such as tropical rainforest and tipping elements of the climate system. Other dynamical systems tools used in ecology and climate science open ways to infer personalized webs of causality for patients that may be used to identify targets for intervention. Meanwhile, experiences in ecological restoration help make sense of the occasional long-term success of short interventions. Conclusions and Relevance: Those observations, while promising, evoke follow-up questions on how best to collect dynamic data, infer informative timescales, construct mechanistic models, and measure the effect of interventions on resilience. Done well, monitoring resilience to inform well-timed interventions may be integrated into approaches that give patients an active role in the lifelong challenge of managing their resilience and knowing when to seek professional help.

Pharmacotherapy of first-episode psychosis.

Early intervention in psychosis has attracted more attention in the last few years. The treatment of this phase of the disorders requires a specific and adapted approach. The issue of engaging the patient is so critical that it influences not only the choice of medication, but also the context and the way in which it is administered. In the case of a first admission, patients should be observed for 24-48 h without any antipsychotic treatment, in order to clarify the diagnosis and exclude the possibility that symptoms are caused by acute intoxication with illicit substances, for example. The diagnosis is often difficult and unstable. A dimensional, rather than a categorical approach, is usually more likely to be adopted. In recent years, atypical antipsychotics have become the most frequently used first-line treatment. They are less likely to cause secondary negative symptoms, cognitive impairments and dysphoria. They also appear to influence the course of depression and hostility/aggression better than conventional neuroleptics, have possibly mood-stabilising properties and, subjectively, are often better accepted by patients. On the risk side, prevalence of acute extrapyramidal side effects and possibly tardive dyskinesia are lower, compared to the older neuroleptics. Although, the risk for short-term weight gain, cardiovascular, and especially hyperglycaemic complications are somewhat higher for some of these antipsychotics. Finally, the dose should be adapted as it has been shown that patients presenting a first psychotic episode respond to a lower dose of antipsychotic. This article focuses on the pharmacotherapy of first-episode psychosis, on the basis of a computerised and a manual search for articles dealing with antipsychotic treatment of these patients. Findings are discussed and combined in clinical guidelines for first-episode affective and non-affective psychosis, for patients with incomplete recovery or treatment resistance, for cases of emergency and for side effects associated with antipsychotic treatment.