The four different types of depression they identified are:
- Biotype 1 is characterised by anxiety, insomnia, and fatigue.
- Biotype 2 is characterised by exhaustion and low energy.
- Biotype 3 is characterised by an inability to feel pleasure as well as slowed movements and speech.
- Biotype 4 is characterised mostly by anxiety with insomnia along with the inability to feel pleasure.
- Biotype 5 is characterised by people who can't see much difference between the Biotypes.