18 Nov Specific Symptom Associations May Determine Persistence of Depression
MedicalResearch.com Interview with:
Claudia van Borkulo, MSc
University of Groningen, University Medical Center Groningen
Department of Psychiatry,
Research School of Behavioural and Cognitive Neurosciences,
Interdisciplinary Center for Psychopathology and Emotion Regulation,
Groningen, the Netherlands
Medical Research: What is the background for this study? What are the main findings?
Response: We consider psychiatric disorders as complex dynamical systems in which symptoms can interact with each other. This novel network approach to psychopathology – that is new to psychiatry – implies that a more densely connected network of symptoms of a disorder might be indicative of worse prognosis. Having one symptom can easily lead to developing more symptoms in a densely connected network, in which more symptoms reinforce each other. Reversely, a symptom in a less densely connected network will rarely turn on other symptoms. A densely connected network can theoretically be related to an increased vulnerability; because of the high level of mutual reinforcement, a small external stressor can induce a quicker transition from a healthy state to a depressed state for people with a more densely connected network.
In our study, we investigated the association between baseline network structure of depression symptoms and longitudinal course of depression. We compared the baseline network structure of persisters (defined as patients with MDD at baseline and depressive symptomatology at 2-year follow-up) and remitters (patients with MDD at baseline without depressive symptomatology at 2-year follow-up). While both groups have similar symptomatology at baseline, persisters have a more densely connected network compared to remitters. More specific symptom associations seem to be an important determinant of persistence of depression.
Medical Research: What should clinicians and patients take away from your report?
Response: Zooming in on individual symptom patterns can reveal interesting information. The level of connectivity of individual symptoms may guide clinical therapy. Symptoms with a central location in the network can be identified as plausible targets for micro-interventions. Since a central symptom is likely to have an influence on many other nodes, intervening on such a symptom might be more effective than general interventions. However, it is important to note that the networks in this study are based on a between-subjects design. Thus, this study is a proof-of-principal and seems a promising line of research; it offers support for a different take on psychopathology, namely that of a network of symptoms.
Medical Research: What recommendations do you have for future research as a result of this study?
Response: As the results in this study are based on a between-subjects design, a first step would be to investigate whether the network structures are generalizable to individual patients. This would require gathering data according to the Experience Sampling Method (ESM). With ESM data, the network of an individual patient can be inferred and related to the course of depression.
According to the network approach, symptoms with an important role in the network may be interesting targets for intervention. However, there are many measures that are indicative for the importance of an element in a network. It has yet to be established which measures are clinically relevant in identifying important symptoms.
Finally, it would be interesting to establish directionality in the networks. Although a symptom can have many connections to other symptoms and, thus, be a central symptom in the network, it is of importance to establish the direction of the influences. If all influences are directed towards the central symptom, it will probably not be an efficient target.
Specific Symptom Associations May Determine Persistence of Depression (2015). Specific Symptom Associations May Determine Persistence of Depression