level of 24.7 ng/dl). The relationship between testosterone and depression was nonlinear in that there is a sharp jump between the third and fourth quintiles, whereas the effects of estrogen on depression appeared to be reasonably linear. In this study, levels of FSH and LH had no effect on depression rates over and above those accounted for by testosterone and estrogen. The findings of this study parallel previous findings that negative affect is associated with higher levels of androgens and estrogens in adolescent girls and imply that hormones rather than physical status are the 'active ingredient' in the effects of puberty on depression in girls (Angold et al., 1999).

More recently, Angold and colleagues hypothesized that the apparent effects of both testosterone and estrogen could represent an intracellular estrogenic effect (Angold et al., 2003), since when behavioral effects of testosterone in animals have been investigated at the level of the brain receptors involved, most have proven to occur via estrogen receptors following intracellular aromatization, or conversion, of testosterone to estrogen (Hutchison, Schumacher, Steimer, & Gahr, 1990; Rasmussen, Torres-Aleman, MacLusky, Naftolin, & Robbins, 1990). Using the same sample of girls from previously described studies, the researchers combined levels of testosterone and estrogen, instead of entering testosterone and estrogen separately in analyses. The rationale for this decision was that both may act on the same receptors in their effects on depression. The sum of the measured molarities of testosterone and estrogen was called sex steroid level (SSL). The distribution of SSL was divided into deciles, and the prevalence of depression was plotted in the deciles. The plot showed pronounced threshold effects of SSL groups based on 3 cutpoints; the difference between each group was significant, with the highest rate of depressive symptoms for the SSL group in the 80th percentile and above. Additional analyses showed that the effects of pubertal hormone status were not explained by either changes in levels of life events or by the interaction of life events and SSL status. The threshold effect of the SSL hormones is similar to the findings of Brooks-Gunn and Warren (1989), in which a significant quadratic effect was found for girls' depressive symptoms, with highest levels of depressive symptoms in the groups that demonstrated initial increases in hormones. Both studies underscore the need to consider linear and nonlinear models when examining effects of hormones on behaviors.

Anxiety and Depression 101

Anxiety and Depression 101

Everything you ever wanted to know about. We have been discussing depression and anxiety and how different information that is out on the market only seems to target one particular cure for these two common conditions that seem to walk hand in hand.

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