The relationship between cognitive functioning and psychopathology in patients with psychiatric disorders: a transdiagnostic network analysis

BACKGROUND

Patients with psychiatric disorders often experience cognitive dysfunction, but the precise relationship between cognitive deficits and psychopathology remains unclear. We investigated the relationships between domains of cognitive functioning and psychopathology in a transdiagnostic sample using a data-driven approach.

METHODS

Cross-sectional network analyses were conducted to investigate the relationships between domains of psychopathology and cognitive functioning and detect clusters in the network. This naturalistic transdiagnostic sample consists of 1016 psychiatric patients who have a variety of psychiatric diagnoses, such as depressive disorders, anxiety disorders, obsessive-compulsive and related disorders, and schizophrenia spectrum and other psychotic disorders. Psychopathology symptoms were assessed using various questionnaires. Core cognitive domains were assessed with a battery of automated tests.

RESULTS

Network analysis detected three clusters that we labelled: general psychopathology, substance use, and cognition. Depressive and anxiety symptoms, verbal memory, and visual attention were the most central nodes in the network. Most associations between cognitive functioning and symptoms were negative, i.e. increased symptom severity was associated with worse cognitive functioning. Cannabis use, (subclinical) psychotic experiences, and anhedonia had the strongest total negative relationships with cognitive variables.

CONCLUSIONS

Cognitive functioning and psychopathology are independent but related dimensions, which interact in a transdiagnostic manner. Depression, anxiety, verbal memory, and visual attention are especially relevant in this network and can be considered independent transdiagnostic targets for research and treatment in psychiatry. Moreover, future research on cognitive functioning in psychopathology should take a transdiagnostic approach, focusing on symptom-specific interactions with cognitive domains rather than investigating cognitive functioning within diagnostic categories.

The social instability stress paradigm in rat and mouse: A systematic review of protocols, limitations, and recommendations

BACKGROUND

Social stress is an important environmental risk factor for the development of psychiatric disorders, including depression and anxiety disorders. Social stress paradigms are commonly used in rats and mice to gain insight into the pathogenesis of these disorders. The social instability stress (SIS) paradigm entails frequent (up to several times a week) introduction of one or multiple unfamiliar same-sex home-cage partners. The subsequent recurring formation of a new social hierarchy results in chronic and unpredictable physical and social stress.

PURPOSE

We compare and discuss the stress-related behavioral and physiological impact of SIS protocols in rat and mouse, and address limitations due to protocol variability. We further provide practical recommendations to optimize reproducibility of SIS protocols.

METHODS

We conducted a systematic review in accordance with the PRISMA statement in the following three databases: PubMed, Web of Science and Scopus. Our search strategy was not restricted to year of publication but was limited to articles in English that were published in peer-reviewed journals. Search terms included "social* instab*" AND ("animal" OR "rodent" OR "rat*" OR "mice" OR "mouse").

RESULTS

Thirty-three studies met our inclusion criteria. Fifteen articles used a SIS protocol in which the composition of two cage mates is altered daily for sixteen days (SIS16D). Eleven articles used a SIS protocol in which the composition of four cage mates is altered twice per week for 49 days (SIS49D). The remaining seven studies used SIS protocols that differed from these two protocols in experiment duration or cage mate quantity. Behavioral impact of SIS was primarily assessed by quantifying depressive-like, anxiety-like, social-, and cognitive behavior. Physiological impact of SIS was primarily assessed using metabolic parameters, hypothalamus-pituitary-adrenal axis activity, and the assessment of neurobiological parameters such as neuroplasticity and neurogenesis.

CONCLUSION

Both shorter and longer SIS protocols induce a wide range of stress-related behavioral and physiological impairments that are relevant for the pathophysiology of depression and anxiety disorders. To date, SIS16D has only been reported in rats, whereas SIS49D has only been reported in mice. Given this species-specific application as well as variability in reported SIS protocols, additional studies should determine whether SIS effects are protocol duration- or species-specific. We address several issues, including a lack of consistency in the used SIS protocols, and suggest practical, concrete improvements in design and reporting of SIS protocols to increase standardization and reproducibility of this etiologically relevant preclinical model of social stress.

Acceptability of internet-based interventions for depression in Indonesia

BACKGROUND

In Indonesia, internet-based interventions may represent a promising strategy to reduce the mental health gap given that the level of internet usage in the country continues to increase. To check the acceptability of internet-based interventions, this study investigates factors that contribute to the use of internet-based interventions for depression in Indonesia.

METHOD

The survey was conducted online and had 904 participants recruited from specific social networks on mental health and general social media (Mean age = 27.07, 50.22% females). The three dependent variables were (1) behavioral intention to start using internet-based interventions for depression, (2) preference to use it as a substitute for regular treatments and (3) preference to use it to complement regular treatments. The predictor variables included sociodemographic characteristics, perceived mental health conditions, personal situational characteristics, personal innovativeness toward online services, and depression level.

RESULTS

A large majority reported to be open to using internet-based interventions for depression (73.7%), as well as to use it as a substitution (73.3%) or as a complementary (73%) to regular treatments. Personal innovativeness toward online services was the strongest significant predictor for all types of use, even when corrected for current depression level. When added to the analyses separately, depression level was the second strongest predictive factor for all dependent variables.

CONCLUSION

The majority of Indonesians showed openness to use internet-based interventions for depression. To increase the adoption of internet-based interventions for depression, it is important to first promote internet usage to more people across the country, especially for those who are currently depressed.

Imagine your mood: Study design and protocol of a randomized controlled micro-trial using app-based experience sampling methodology to explore processes of change during relapse prevention interventions for recurrent depression

Background

Relapse prevention strategies include continuation of antidepressant medication and preventive psychological interventions. This study aims to gain understanding that may inform tailoring of relapse prevention to individual differences, to improve their effects. Such treatment personalization may be based on repeated assessments within one individual, using experience sampling methodology. As a first step towards informing decisions based on this methodology, insight is needed in individual differences in risk of relapse and response to treatment, and how relapse prevention strategies may differentially target vulnerability for relapse.

Methods

The smartphone application ‘Imagine your mood’ has been developed specifically for this study to assess emotions, imagery, cognitions, and behaviors in daily life. Parallel to the randomized controlled trial ‘Disrupting the rhythm of depression’, 45 remitted recurrently depressed individuals taking continuation antidepressant medication will be randomly assigned to either continuing antidepressant medication (n = 15), continuing antidepressant medication combined with an eight-session preventive cognitive therapy (n = 15), or tapering of antidepressant medication in combination with preventive cognitive therapy (n = 15). Relapse and return of depressive symptomatology over a 24-month follow-up will be assessed. Additionally, matched never depressed individuals (n = 15) will be recruited as controls.

Discussion

This innovative study combines the strengths of a randomized controlled trial and experience sampling methodology in a micro-trial to explore individual differences in risk of relapse and what works for whom to prevent relapse. Results may ultimately pave the way for therapists to tailor relapse prevention strategies to individual (affective) vulnerability.

Trial registration

ISRCTN15472145, retrospectively registered.

Non-fatal disease burden for subtypes of depressive disorder: population-based epidemiological study

BACKGROUND

Major depression is the leading cause of non-fatal disease burden. Because major depression is not a homogeneous condition, this study estimated the non-fatal disease burden for mild, moderate and severe depression in both single episode and recurrent depression. All estimates were assessed from an individual and a population perspective and presented as unadjusted, raw estimates and as estimates adjusted for comorbidity.

METHODS

We used data from the first wave of the second Netherlands-Mental-Health-Survey-and-Incidence-Study (NEMESIS-2, n = 6646; single episode Diagnostic and Statistical Manual (DSM)-IV depression, n = 115; recurrent depression, n = 246). Disease burden from an individual perspective was assessed as 'disability weight * time spent in depression' for each person in the dataset. From a population perspective it was assessed as 'disability weight * time spent in depression *number of people affected'. The presence of mental disorders was assessed with the Composite International Diagnostic Interview (CIDI) 3.0.

RESULTS

Single depressive episodes emerged as a key driver of disease burden from an individual perspective. From a population perspective, recurrent depressions emerged as a key driver. These findings remained unaltered after adjusting for comorbidity.

CONCLUSIONS

The burden of disease differs between the subtype of depression and depends much on the choice of perspective. The distinction between an individual and a population perspective may help to avoid misunderstandings between policy makers and clinicians.

DHEAS and cortisol/DHEAS-ratio in recurrent depression: State, or trait predicting 10-year recurrence?

BACKGROUND

Major depressive disorder (MDD) has been associated with low dehydroepiandrosterone-sulphate (DHEAS), - particularly relative to high cortisol - although conflicting findings exist. Moreover, it is unclear whether low DHEAS is only present during the depressive state, or manifests as a trait that may reflect vulnerability for recurrence. Therefore, we longitudinally tested whether low DHEAS and high cortisol/DHEAS-ratio in recurrent MDD (I) reflects a trait, and/or (II) varies with depressive state. In addition, we tested associations with (III) previous MDD-episodes, (IV) prospective recurrence, and (V) effects of cognitive therapy.

METHODS

At study-entry, we cross-sectionally compared morning and evening salivary DHEAS and molar cortisol/DHEAS-ratio of 187 remitted recurrent MDD-patients with 72 matched controls. Subsequently, patients participated in an 8-week randomized controlled cognitive therapy trial. We repeated salivary measures after 3 months and 2 years. We measured clinical symptoms during a 10-year follow-up.

RESULTS

Remitted patients showed steeper diurnal DHEAS-decline (p<.005) and a flatter diurnal profile of cortisol/DHEAS-ratio (p<.001) than controls. We found no state-effect in DHEAS or cortisol/DHEAS-ratio throughout follow-up and no association with number of previous episodes. Higher morning cortisol/DHEAS-ratio predicted shorter time till recurrence over the 10-year follow-up in interaction with the effects of cognitive therapy (p<.05). Finally, cognitive therapy did not influence DHEAS or cortisol/DHEAS-ratio.

CONCLUSIONS

Diurnal profiles of DHEAS and cortisol/DHEAS-ratio remain equally altered in between depressive episodes, and may predict future recurrence. This suggests they represent an endophenotypic vulnerability trait rather than a state-effect, which provides a new road to understand recurrent depression and its prevention.

TRIAL REGISTRATION

www.isrctn.com/ISRCTN68246470.

Fatty acids and homocysteine levels in patients with recurrent depression: an explorative pilot study

Major depressive disorders (MDD) and cardiovascular disease are mutually associated. They share signs and symptoms of the "metabolic syndrome". Two observations that may be causally related with the metabolic syndrome and therefore with both MDD and cardiovascular disease are a decrease in omega-3 polyunsaturated fatty acids (PUFAs) and a rise in plasma homocysteine (tHcy) levels. Both the rise in tHcy and the decrease in omega-3 PUFAs may be associated with enhanced lipid peroxidation. We exploratively studied 44 randomly chosen patients out of a cohort of 134 patients with the recurrent form of MDD (MDD-R). We measured tHcy levels together with saturated FAs, monounsaturated fatty acids (MUFAs) and PUFAs of the omega-3, omega-6 and omega-9 series in plasma and erythrocytes. Levels were compared with laboratory reference values. The main findings were a decrease in the erythrocytes of C22:5omega-3, C22:6omega-3, C24:1omega-9 and C20:3omega-9 and in the plasma a decrease in C24:1omega-9 and C20:3omega-9. The only significant association we found was between the total of omega-6 fatty acids and plasma tHcy. The FA alterations were found in patients although most of them were clinically recovered, suggesting that the alterations may represent a biological" trait" marker for recurrent depression.