Mental conditions can sometimes be covered by workers' comp if you can prove the mental or psychiatric problem was primarily caused by your work. Generally, it must be shown that the mental condition was the result of abnormal work conditions.
However, psychological cases, such as a claim for work-induced stress, are very hard to win, especially without a workers' comp lawyer. And it can be hard to find a workers' comp lawyer to take your case, since the chance of winning are poor, and the lawyer will get paid only if you win your case. Furthermore, the chances of winning a permanent disability award is even more slim (since you would be expected to recover after you left the job), and workers' comp lawyers are paid through a percentage of your permanent disability benefits. In many cases, the most you could reasonably hope for is to get compensated for your medical expenses and some temporary disability benefits to replace your wages while you take some time off work.
If your psychological or psychiatric condition is tied to a physical accident at work or an illness caused by work, you would have a better chance of being compensated. For example, job-related stress or tension may contribute to a heart attack. Another example might be a worker who suffers a traumatic physical injury and later develops anxiety disorder or PTSD (post-traumatic stress disorder) as a result.
In many cases, if you have a severe mental impairment that prevents you from going back to work, your best bet would be to file for Social Security disability based on your mental condition.