In: Psychology
1) Exposure therapy , CBT can be used for treating phobia for snakes.Medications can also be used for severe cases: Phobia of snakes can be caused due to learned behaviour,negative experiences, imitating the behaviour etc. In exposure therapy exposure is done in a non threatening manner, such as seeing pictures, touching the snake dummies etc.Finally the transition to the real scenarios.CBT is also used for this(explained in the following part).
2) Behavioural therapy and CBT can be used for aggression issues: Aggression issues can outsurface because of low self esteem, emotional conflicts, etc. Psychosocial CBT can play role in alleviating aggression by highlighting the cognitive distortions, underlying thoughts, feelings and related behaviour .
3) ADHD in adults is a reason why they leave jobs so often and are not able to concentrate : The first preference would be choosing a career that involves physical needs and recurrent shifts of focus, such as firefighting, police etc.Medications,Behaviour therapy, physical exercices ( to curb the bouts of physical motion).
Good luck!