The role of retinal irradiance estimates in melanopsin-driven retinal responsivity: A reanalysis of the post-illumination pupil response (PIPR) in seasonal affective disorder.

To isolate melanopsin contributions to retinal sensitivity measured by the post-illumination pupil response (PIPR), controlling for individual differences in non-melanopsin contributions including retinal irradiance is required. When methodologies to negate such differences present barriers, statistical controls have included age, baseline diameter, iris pigmentation, and circadian time of testing. Alternatively, the pupil light reflex (PLR) and calculations estimating retinal irradiance both reflect retinal irradiance, while the PLR also reflects downstream pathways. We reanalyzed data from an observational, correlational study comparing the PIPR across seasons in seasonal affective disorder (SAD) and controls. The PIPR was measured in 47 adults in Pittsburgh, Pennsylvania (25 SAD) over 50 s after 1 s red and blue stimuli of 15.3 log photons/cm2/s. The PLR was within 1 s while PIPR was averaged over 10-40 seconds post-stimulus. Two raters ranked iris pigmentation using a published scale. We evaluated model fit using Akaike's Information Criterion (AIC) across different covariate sets. The best fitting models included either estimated retinal irradiance or PLR, and circadian time of testing. The PLR is collected contemporaneously in PIPR studies and is an individually specific measure of nonspecific effects, while being minimally burdensome. This work extends the prior publication by introducing theoretically grounded covariates that improved analytic model fits based on AIC specific to the present methods and sample. Such quantitative methods could be helpful in studies which must balance participant and researcher burden against tighter methodological controls of individual differences in retinal irradiance.

Circadian photoentrainment varies by season and depressed state: associations between light sensitivity and sleep and circadian timing.

STUDY OBJECTIVES: Altered light sensitivity may be an underlying vulnerability for disrupted circadian photoentrainment. The photic information necessary for circadian photoentrainment is sent to the circadian clock from melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs). The current study tested whether the responsivity of ipRGCs measured using the post-illumination pupil response (PIPR) was associated with circadian phase, sleep timing, and circadian alignment, and if these relationships varied by season or depression severity. METHODS: Adult participants (N = 323, agem = 40.5, agesd = 13.5) with varying depression severity were recruited during the summer (n = 154) and winter (n = 169) months. Light sensitivity was measured using the PIPR. Circadian phase was assessed using Dim Light Melatonin Onset (DLMO) on Friday evenings. Midsleep was measured using actigraphy. Circadian alignment was calculated as the DLMO-midsleep phase angle. Multilevel regression models covaried for age, gender, and time since wake of PIPR assessment. RESULTS: Greater light sensitivity was associated with later circadian phase in summer but not in winter (ß = 0.23; p = 0.03). Greater light sensitivity was associated with shorter DLMO-midsleep phase angles (ß = 0.20; p = 0.03) in minimal depression but not in moderate depression (SIGHSAD < 6.6; Johnson-Neyman region of significance). CONCLUSIONS: Light sensitivity measured by the PIPR was associated with circadian phase during the summer but not in winter, suggesting ipRGC functioning in humans may affect circadian entrainment when external zeitgebers are robust. Light sensitivity was associated with circadian alignment only in participants with minimal depression, suggesting circadian photoentrainment, a possible driver of mood, may be decreased in depression year-round, similar to decreased photoentrainment in winter.

Social functioning mediates the relationship between psychiatric symptoms and recovery among veteran and community service users with serious mental illness.

OBJECTIVE: Previous research has established the impact of psychiatric symptoms on social functioning, while there is a paucity of research examining how social functioning relates to personal recovery, an individual's self-assessment of their mental health recovery. This study examined the mediating effect of social engagement, interpersonal communication, and satisfaction with support in the relationship between distinct psychiatric symptom clusters and perceived mental health recovery. METHODS: In a cross-sectional study, both patient self-report and provider assessment data were collected for 250 patients with serious mental illness (SMI) across four mental health service sites. Parallel mediation analytic models were used. RESULTS: Interpersonal communication partially mediated the relationship between positive and negative symptom clusters and personal recovery. Satisfaction with social supports partially mediated the relationship between excited symptoms and personal recovery. Both interpersonal communication and satisfaction with social supports partially mediated the relationship between general psychological distress and depressive symptoms and personal recovery. Collectively, social functioning mediators explained nearly half of the relationship between general psychological distress and excited symptoms and personal recovery and nearly all of the relationship between positive symptoms and personal recovery. CONCLUSIONS AND IMPLICATIONS FOR PRACTICE: Clinical providers working with persons with SMI should regularly assess social functioning in addition to assessing psychiatric symptoms and personal recovery factors and should incorporate social skills education into SMI group and individual treatments. Social functioning as a target of treatment may be especially beneficial for patients who are dissatisfied with other interventions or feel they have experienced the maximum benefit from treatment and are seeking additional methods to support personal recovery. (PsycInfo Database Record (c) 2023 APA, all rights reserved).