Longitudinal dynamics between anxiety and depression in bipolar spectrum disorders.

Today, I am examining three studies of adults, each examining trajectories. First, Kim, McInnis & Sperry (2024) published “Longitudinal Dynamics between Anxiety and Depression in Bipolar Spectrum Disorders” in Journal of Psychopathology and Clinical Science. Here are the edited abstract and impact statements:

Anxiety and depression are common among individuals with bipolar spectrum disorders (BSDs), with anxiety being a risk factor for depression and vice versa. While the harmful effects of these symptoms are well recognized, their temporal dynamics have not been fully tested. To address this gap, our study investigated bidirectional relationships between anxiety and depression in individuals with BSDs using data from the Prechter Longitudinal Study of Bipolar Disorder, collected over an average of 11 years. We included 651 participants with various BSD subtypes (BD I, BD II, BD not otherwise specified, and schizoaffective bipolar type), with at least 5 years’ data for adequate statistical power in detecting temporal dynamics. Bimonthly measurements of anxiety and depression were analyzed using dynamic structural equation modeling. Beyond assessing autoregressive and cross-lagged effects, this study also investigated whether temporal dynamics differed based on demographic characteristics and the use of psychiatric medication. Our findings revealed that individuals with BSDs experienced significant fluctuations in anxiety and depression over time. Comparison of the cross-lagged effects demonstrated that anxiety had a greater effect on subsequent depression than vice versa. Age and marital status impacted cross-lagged and autoregressive effects. 

Our findings revealed significant autoregressive and cross-lagged effects of anxiety and depression, with anxiety exerting a more pronounced cross-lagged influence on subsequent depression than vice versa. Moreover, older individuals displayed more robust temporal associations between depression and subsequent anxiety, while widowed individuals exhibited heightened connections between depression and subsequent depression. These findings underscore the importance of early identification and intervention strategies targeting anxiety and depression in individuals with BSDs. 

For professionals who work with adults with BPD this work is helpful in several ways. The finding that anxiety impacts depression more than the opposite is helpful, as are the findings regarding older adults and widowed persons. 

The next study looks at affective trajectories in general. Cintron& Ong (2024) published “Trajectories of Affective Well-being and Survival in Middle-aged and Older Adults” in Emotion. Here’s the abstract:

Affective experiences are key components of subjective well-being with important implications for health. However, little is known about heterogeneous longitudinal affect trajectories and their links to survival. This study identified joint trajectory subgroups based on 18-year changes in positive affect (PA) and negative affect (NA) and examined their differential associations with mortality risk. Participants were 3,250 adults (aged 39–93 years) from the Midlife in the U.S. study assessed over three waves (1995–2013). Parallel growth mixture modeling revealed three subgroups: (a) improving (increasing PA, decreasing NA), (b) deteriorating (decreasing PA, increasing NA), and (c) flourishing (high, stable PA, low, stable NA). Adjusting for baseline demographic and health covariates, Cox proportional-hazard results showed the improving group had the lowest mortality risk (HR = 0.82, 95% CI [0.35, 1.32]) and the deteriorating group had the highest mortality risk (HR = 1.86, 95% CI [1.34, 3.55]), relative to flourishing. These findings highlight the importance of modeling multidimensional trajectories of affective well-being and their heterogeneous links to survival. 

This is a large sample and I find the three trajectories potentially helpful, especially to therapists. It’s not at all surprising that those people who fall in the improving category (which in the developmental literature has been seen as most common in middle adulthood) have the lowest mortality risk. It also highlights the urgency of interventions in the deteriorating group.

Finally, Komischke-Konnerup, Vang, Lundorff, Elklit & O'Connor (2023) published “Do Early Symptoms of Prolonged Grief Disorder Lead to Symptoms of Posttraumatic Stress Disorder and Depression? A longitudinal register-based study of the two first years of bereavement” in Journal of Psychopathology and Clinical Science. The edited abstract and impact statements follow:

Symptoms of prolonged grief disorder (PGD), depression, and posttraumatic stress disorder (PTSD) often emerge concurrently in bereavement. The understanding of temporal relationships between these syndromes in a general bereaved population is limited. This study aims to investigate temporal relationships between these syndromes from 2 months postloss throughout the two first years of bereavement. Data were derived from a registry-based cohort study with 1,224 adult participants, who lost a spouse or parent. Participants completed self-report measures of PGD, depression, and PTSD at 2, 6, 11, 18, and 26 months postloss. Random intercept cross-lagged panel analyses examined the temporal relationships between PGD, PTSD, and depression. In spousal and parental bereavement, high levels of grief symptoms at 2 months postloss predicted subsequent high symptoms of PTSD and depression at 6 months postloss, not vice versa. PGD, PTSD, and depression showed strong intertwined relationships over the two first years of bereavement. Between-person differences explained an increasingly large amount of variance in symptoms of PGD, PTSD, and depression over time. Losing a spouse and younger age was associated with higher symptoms of PGD, PTSD, and depression compared to losing a parent and older age. In the early years of bereavement, large differences exist between bereaved individuals in general levels of PGD, PTSD, and depression. Within bereaved individuals, the temporal relationships between these syndromes become increasingly complex and intertwined over time. Findings should be interpreted with respect to the nonclinical sample and self-report data used. 

This study suggests that high levels of early grief symptoms evolve into symptoms of posttraumatic stress disorder (PTSD) and depression within bereaved individuals. Furthermore, symptoms of prolonged grief disorder (PGD), PTSD, and depression become increasingly intertwined through the first years of spousal and parental bereavement. 

This is a fairly large sample and, in my view, another study helpful to those who work with bereaved adults. The findings about younger age and spousal death are unsurprising in that they involve violations of normative expectations. However, the intertwining of prolonged grief, post-traumatic stress, and depression over time may be very important for therapists to understand.