Twenty doctors referred to medical watchdog over substance abuse
Substance abuse was cited as the reason 20 doctors were referred to a special health committee of their regulatory body last year.
Another 23 medics had a mental disability, the annual report of the Medical Council revealed.
Although 407 complaints against doctors were assessed by the watchdog, just 56 made it to a full sworn inquiry.
Poor communication sparked the greatest number of complaints, with 126 grievances due to failure of the doctor to provide appropriate information or respond to people's concerns.
The council said it can amount to a "miscommunication, not explaining a diagnosis or treatment plan in an understandable or clear manner, a disagreement, or simply a personality clash.
"In a large number of cases these issues can be dealt with by a simple apology where appropriate or with mediation."
However, a litany of other complaints were also made, including issues with intimate examinations, prescribing, a refusal to treat a patient, dishonesty and also inappropriate relationships with the person they were treating.
Chief executive Bill Prasifka said: "When communicating with patients, a doctor should be honest and give all relevant information.
"A doctor should welcome questions from patients and respond to them in an open, honest and comprehensive way."
The council has the power to impose sanctions after a fitness to practise inquiry and three doctors were struck off. Nine others were sanctioned but allowed to continue to practise.
There are 22,649 doctors on the medical register - a rise of 4pc compared with 2016.
There were 13 inquiries into doctors held in public last year - down from 18 in 2015.