Methods and systems for treating anxiety and depression

A method of treating anxiety or depression, comprising:

• administering a therapeutically effective amount of a bilaterally alternating sensory stimulus to a user via a headset, wherein the sensory stimulus includes a visual stimuli or an auditory stimuli;
• obtaining a sequence of measurements of beat-to-beat intervals of a heart of the user using a heart rate sensor;
• calculating values of heart rate variability using the sequence of measurements of beat-to-beat intervals of the heart of the user, including first and second values of heart rate variability respectively corresponding to a first time period and a second time period that is later than the first time period;
• calculating a change in heart rate variability based on at least the first and second values of heart rate variability;
• determining a state of the user based on the calculated change in heart rate variability, including determining a first state of the user based on the calculated change being positive and determining a second state of the user based on the calculated change being negative;
• and
• modifying the sensory stimulus according to the state of the user, including reducing an intensity of the sensory stimulus based on the user being in the first state and increasing an intensity of the sensory stimulus based on the user being in the second state,
• wherein the sensory stimulus further includes a first stimuli pattern and a second stimuli pattern that is different than the first stimuli pattern,
• wherein the first stimuli pattern includes a first repetitive component corresponding to at least one of a delta, theta, or alpha brain wave frequency, and wherein the second stimuli pattern includes a second repetitive component corresponding to a different duration of applied stimuli at the at least one delta, theta, or alpha brain wave frequency.