The impact of mental health problems has been extensively researched in the literature through the different life stages, particularly because of its relation to difficulties in life trajectory. However, the research is limited on later treatment seeking and treatment outcome for depression and anxiety.

The objectives of this study were to explore childhood predictors of treatment seeking for adult depression and anxiety; to investigate the patterns of mental health service utilisation in adulthood; and to examine the types of treatment used.

This study used data from the Christchurch Health and Development study, a prospective longitudinal study involving 1265 participants recruited at birth. This current research utilised 5 waves of data, consisting of 1011 (496 men and 515 women) participants at age 21; 1003 (488 men and 515 women) participants at age 25; 987 (478 men and 509 women) participants at age 30; 962 (463 men and 499 women) participants at age 35; and 904 (431 men and 473 women) participants at age 40. At age 40, the sample consisted of 17.8% of individuals who identified as Māori and 82.2% as non-Māori. Participants were assessed for mental health problems, such as depression and anxiety, and treatment seeking at ages 21, 25, 30, 35 and 40 year assessments.

The findings were that individuals, especially women, were more likely to seek treatment, especially as they aged. Individuals with depression were more likely to seek treatment than those with anxiety. The childhood determinants of later service use for depression were childhood adversity, identifying as female, higher neuroticism, identifying as non-Māori and higher paternal education. For anxiety, determinants were childhood adversity, identifying as female and higher neuroticism. When time-dynamic covariates were included, cannabis use disorder, alcohol use disorder and life stress became significant predictors of treatment seeking for depression. The results were similar for treatment seeking for anxiety except for alcohol use disorder which was not significant.

In conclusion, individuals who identified as female, had exposure to childhood adversity, identified as non-Māori, had neuroticism as a personality trait, and whose fathers had higher education, were more inclined to seek treatment for their mental well-being. This research also found that accumulative factors such as experiencing alcohol and cannabis problems, and life stress may serve as contributing factors to seeking treatment, consistent with an allostatic load explanation.