Depression and coronary heart disease (CHD) are highly comorbid conditions. Brain-derived neurotrophic factor (BDNF) plays an important role in cardiovascular processes. Depressed patients typically show decreased BDNF concentrations. We analysed the relationship between BDNF and depression in a sample of patients with CHD and additionally distinguished between cognitive-affective and somatic depression symptoms. We also investigated whether BDNF was associated with somatic comorbidity burden, acute coronary syndrome (ACS) or congestive heart failure (CHF).

The following variables were assessed for 225 hospitalised patients with CHD: BDNF concentrations, depression [Patient Health Questionnaire-9 (PHQ-9)], somatic comorbidity (Charlson Comorbidity Index), CHF, ACS, platelet count, smoking status and antidepressant treatment.

Regression models revealed that BDNF was not associated with severity of depression. Although depressed patients (PHQ-9 score >7) had significantly lower BDNF concentrations compared to non-depressed patients (p = 0.04), this was not statistically significant after controlling for confounders (p = 0.15). Cognitive-affective symptoms and somatic comorbidity burden each closely missed a statistically significant association with BDNF concentrations (p = 0.08, p = 0.06, respectively). BDNF was reduced in patients with CHF (p = 0.02). There was no covariate-adjusted, significant association between BDNF and ACS.

Serum BDNF concentrations are associated with cardiovascular dysfunction. Somatic comorbidities should be considered when investigating the relationship between depression and BDNF.

We studied the cumulative incidence of physical illnesses, and the effect of early environmental factors (EEFs) on somatic comorbidity in schizophrenia, in nonschizophrenic psychosis and among nonpsychotic controls from birth up to the age of 50 years.

The sample included 10,933 members of the Northern Finland Birth Cohort 1966, of whom, 227 had schizophrenia and 205 had nonschizophrenic psychosis. Diagnoses concerning physical illnesses were based on nationwide registers followed up to the end of 2016 and classified into 13 illness categories. Maternal education and age, family type at birth and paternal socioeconomic status were studied as EEFs of somatic illnesses.

When adjusted by gender and education, individuals and especially women with nonschizophrenic psychosis had higher risk of morbidity in almost all somatic illness categories compared to controls, and in some categories, compared to individuals with schizophrenia. The statistically significant adjusted hazard ratios varied from 1.27 to 2.42 in nonschizophrenic psychosis. Regarding EEFs, single-parent family as the family type at birth was a risk factor for a higher somatic score among men with schizophrenia and women with nonschizophrenic psychosis. Maternal age over 35 years was associated with lower somatic score among women with nonschizophrenic psychosis.

Persons with nonschizophrenic psychoses have higher incidence of somatic diseases compared to people with schizophrenia and nonpsychotic controls, and this should be noted in clinical work. EEFs have mostly weak association with somatic comorbidity in our study.

Somatic diseases have been associated with an increased risk for subsequent schizophrenia; however, it is unknown whether prior somatic diseases negatively affect early treatment outcomes after a first-time schizophrenia diagnosis.

We included all individuals born in Denmark after January 1st, 1977 and first-time diagnosed with schizophrenia between January 1st, 1996 and December 31st, 2015. We identified all life-time somatic hospital contacts and all prescriptions within the year before the first-time schizophrenia diagnosis and followed patients for up to five years regarding risk for schizophrenia (re)-hospitalization (relapse). We performed Cox regression analyses calculating hazard rate ratios (HRR) including 95%-confidence intervals (CI) and adjusted for relevant confounders.

We followed a total of 11,856 patients with a first-time schizophrenia diagnosis (58.7% male, mean age 23.1 (SD = 4.7) years) for 39,033 person-years, whereof 5506 (46.4%) had relapse with schizophrenia re-hospitalization during 5-year of follow-up. Somatic hospital contacts ever before (95.4%; HRR = 1.30; 95%-CI = 1.07–1.59), and specifically during the year before schizophrenia diagnosis (42.5%; HRR = 1.36; 95%-CI = 1.11–1.66) were associated with an increased risk of schizophrenia relapse as were a greater number of prior somatic hospital contacts (p < 0.001). Individuals with up to four different prescriptions for somatic medications showed a trend towards a slightly lower risk of relapse.

Somatic diseases and health seeking patterns might have an impact on the course of schizophrenia, where severe somatic comorbidity, specifically during the year before first-time schizophrenia diagnosis, seem to negatively affect early treatment course, whereas previous somatic medication use may indicate a better compliance and help-seeking behavior.