Mental health antecedents of early midlife insomnia: evidence from a four-decade longitudinal study

Abstract

Study objectives: Insomnia is a highly prevalent condition that constitutes a major public health and economic burden. However, little is known about the developmental etiology of adulthood insomnia.

Design: We examined whether indicators of psychological vulnerability across multiple developmental periods (psychiatric diagnoses in young adulthood and adolescence, childhood behavioral problems, and familial psychiatric history) predicted subsequent insomnia in adulthood.

Setting and participants: We used data from the ongoing Dunedin Multidisciplinary Health and Development Study, a population-representative birth cohort study of 1,037 children in New Zealand who were followed prospectively from birth (1972-1973) through their fourth decade of life with a 95% retention rate.

Measurements: Insomnia was diagnosed at age 38 according to DSM-IV criteria. Psychiatric diagnoses, behavioral problems, and family psychiatric histories were assessed between ages 5 and 38.

Results: In cross-sectional analyses, insomnia was highly comorbid with multiple psychiatric disorders. After controlling for this concurrent comorbidity, our results showed that individuals who have family histories of depression or anxiety, and who manifest lifelong depression and anxiety beginning in childhood, are at uniquely high risk for age-38 insomnia. Other disorders did not predict adulthood insomnia.

Conclusions: The link between lifelong depression and anxiety symptoms and adulthood insomnia calls for further studies to clarify the neurophysiological systems or behavioral conditioning processes that may underlie this association.

Keywords: anxiety; depression; insomnia.

Figure 1

Insomnia diagnosis status and psychiatric comorbidity at age 38 years. Bars depict, among study members with age-38 insomnia (dark gray bars) and without age-38 insomnia (light gray bars), the percent with zero, one, two, or ≥ 3 concurrent psychiatric conditions (including major depression, generalized anxiety disorder, any fear or phobia, post-traumatic stress disorder, alcohol dependence, cannabis dependence, and hard drug dependence).

Figure 2

Dose-response relationships between lifecourse internalizing disorders and midlife insomnia. Bars depict percentage of study members diagnosed with insomnia at age 38 years, according to their number of lifetime diagnoses with depression (left-side, light gray bars) and anxiety (right-side, dark gray bars).