Autistic children and adults are at increased risk of showing behaviours that may be described as challenging, however, little is known about whether or how these behaviours may change over time. Given the profound impact that challenging behaviour can have on both the autistic individual and their support network, it is critical that the trajectory of challenging behaviours be better understood. This systematic review and meta-analysis identified and synthesised observational longitudinal studies of challenging behaviour in autistic individuals. Fifty-six studies were included in the systematic review, and the effect sizes of 37 independent samples arising from 34 of these reports were examined through meta-analysis. Crucially, across the 37 samples, scores on the measures of challenging behaviour reduced by a small, yet significant, extent over time. Although age of the sample at baseline assessment did not moderate the effect, the time between the baseline assessment and final follow-up and age at final follow-up both moderated the magnitude of the effect, with challenging behaviour scores reducing to a larger extent in (a) studies with longer intervals between baseline and final follow-up and (b) studies with older samples at follow-up. The results from the current systematic review and meta-analysis have both theoretical and practical implications for understanding challenging behaviour over time in autistic individuals. Avenues for future research are also highlighted that may allow better understanding, and therefore support of, challenging behaviour in autistic individuals.

自闭症儿童和成人表现出可能被描述为具有挑战性的行为的风险增加，然而，人们对这些行为是否或如何随着时间的推移而改变知之甚少。鉴于挑战行为可能对自闭症患者及其支持网络产生深远影响，更好地理解挑战行为的轨迹至关重要。这项系统回顾和荟萃分析确定并综合了自闭症患者挑战性行为的观察性纵向研究。系统评价纳入了 56 项研究，并通过荟萃分析检查了其中 34 份报告中的 37 个独立样本的效应大小。至关重要的是，在这 37 个样本中，随着时间的推移，挑战性行为的衡量标准出现了小幅但显着的下降。尽管基线评估时样本的年龄并没有减轻影响，但基线评估和最终随访之间的时间以及最终随访时的年龄都减轻了影响的程度，挑战行为得分在更大程度上降低了(a) 基线和最终随访之间间隔较长的研究；(b) 随访时使用较旧样本的研究。当前的系统评价和荟萃分析的结果对于理解自闭症患者随时间推移的挑战性行为具有理论和实践意义。还强调了未来研究的途径，这些途径可能有助于更好地理解并因此支持自闭症患者的挑战性行为。