Each dyad (mother and their child) will receive 8 sessions of promoting positive emotions intervention with a clinician for 8 weeks.

Mothers will be sent written information and resources on depression for 8 weeks over email.

F-PPE is an 8-session dyadic intervention designed to enhance positive emotionality and buffer against the effects of stress on anhedonia in children. The intervention will be administered online through videoconferencing sessions with a clinician to mothers and their children.

The National Institutes of Health Toolbox Perceived Stress survey consists of 10 questions with options ranging in value from 1 to 5 to assess self-reported perceived stress for children (self- and parent-report). The minimum score is 10 and the maximum score is 50, with higher values meaning greater stress.

Hypothesis 1a: Children in the F-PPE group will show lower post-intervention perceived stress compared to the written information group.

The Patient-Reported Outcomes Measurement Information System (Anxiety, Depression, Anger) short form consists of questions with five response options ranging in value from 1 to 5 to assess self-reported anxiety, depression, anger and irritability for participants (parent, child, and parent report). Total scores on the emotional distress scales for children range from 33 to 165 for self-report and 26 to 130 for parent report, with higher scores reflect greater distress.

Hypothesis 1b: Children in the F-PPE group will show lower post-intervention emotional distress compared to the written information group.

Positive affect will be assessed using the positive affect scale of the Positive and Negative Affect Schedule for Children administered through ecological momentary assessment over 10 days. Children rate their current affect on 5 items with a 1 to 5 scale for total scores from 5 to 25, with greater values reflecting greater positive affect.

Hypothesis 2a: Children in the F-PPE group will show relative increases in daily positive affect from pre- to post-intervention compared to the written information condition.

Hypothesis 2b: Changes in positive affect will partly account for F- PPE effects on child perceived stress and emotional distress.

Hypothesis 2c: Changes in positive affect will partly account for F- PPE effects on child perceived stress and emotional distress.

Reward learning will be measured using a Reinforcement Learning Task. The extent to which children begin to preferentially select the button that is more likely to be reinforced as a reward across the task will be used to quantify reinforcement learning.

Hypothesis 3a: Children in the F-PPE group will show relative increases in reward learning from pre- to post-intervention compared to the written information condition.

Hypothesis 3b: Changes in reward learning will partly account for F- PPE effects on child perceived stress and emotional distress.

Hypothesis 3c: Changes in reward learning will partly account for F- PPE effects on child perceived stress and emotional distress.